diff --git a/apps/array-builder/beam-pattern-surface-view.js b/apps/array-builder/beam-pattern-surface-view.js
new file mode 100644
index 0000000..845da76
--- /dev/null
+++ b/apps/array-builder/beam-pattern-surface-view.js
@@ -0,0 +1,429 @@
+const MAX_PIXEL_RATIO = 3;
+const MAX_SURFACE_VIEW_SAMPLES = 20_000;
+const MAX_PITCH_RAD = Math.PI * 0.46;
+const DEFAULT_YAW_RAD = -Math.PI / 5;
+const DEFAULT_PITCH_RAD = Math.PI / 4.5;
+
+function clamp(value, minimum, maximum) {
+  return Math.min(maximum, Math.max(minimum, value));
+}
+
+function numericSequence(value) {
+  return Array.isArray(value) || ArrayBuffer.isView(value);
+}
+
+function formatFrequency(frequencyHz) {
+  if (frequencyHz >= 1_000_000) return (frequencyHz / 1_000_000).toFixed(3) + " MHz";
+  if (frequencyHz >= 1_000) return (frequencyHz / 1_000).toFixed(3) + " kHz";
+  return frequencyHz.toFixed(1) + " Hz";
+}
+
+function surfaceColor(level, alpha = 0.72) {
+  const normalized = clamp(level, 0, 1);
+  const hue = 198 - normalized * 48;
+  const saturation = 58 + normalized * 24;
+  const lightness = 18 + normalized * 48;
+  return `hsla(${hue}, ${saturation}%, ${lightness}%, ${alpha})`;
+}
+
+function validateSurface(surface) {
+  if (!surface || typeof surface !== "object") {
+    throw new TypeError("3D 빔 패턴 결과가 없습니다.");
+  }
+  const azimuthAxisDeg = surface.azimuthAxisDeg;
+  const elevationAxisDeg = surface.elevationAxisDeg;
+  const displayDb = surface.displayDb;
+  if (
+    !numericSequence(azimuthAxisDeg) ||
+    !numericSequence(elevationAxisDeg) ||
+    !numericSequence(displayDb)
+  ) {
+    throw new TypeError("3D 빔 패턴 축과 displayDb는 수치 배열이어야 합니다.");
+  }
+  const rows = Number(surface.gridShape?.[0]);
+  const columns = Number(surface.gridShape?.[1]);
+  if (
+    !Number.isInteger(rows) ||
+    !Number.isInteger(columns) ||
+    rows !== elevationAxisDeg.length ||
+    columns !== azimuthAxisDeg.length ||
+    rows < 2 ||
+    columns < 3 ||
+    displayDb.length !== rows * columns
+  ) {
+    throw new RangeError("3D 빔 패턴 grid shape과 표본 수가 일치하지 않습니다.");
+  }
+  if (rows * columns > MAX_SURFACE_VIEW_SAMPLES) {
+    throw new RangeError(
+      "3D 표시 표본은 " + MAX_SURFACE_VIEW_SAMPLES.toLocaleString("en-US") +
+      "개를 넘을 수 없습니다.",
+    );
+  }
+  const dbFloor = Number(surface.dbFloor);
+  if (!Number.isFinite(dbFloor) || dbFloor >= 0) {
+    throw new RangeError("3D 빔 패턴 dbFloor는 0보다 작은 유한한 값이어야 합니다.");
+  }
+  for (const value of displayDb) {
+    if (!Number.isFinite(Number(value))) {
+      throw new RangeError("3D 빔 패턴 displayDb에는 유한한 값만 사용할 수 있습니다.");
+    }
+  }
+  return { azimuthAxisDeg, elevationAxisDeg, displayDb, rows, columns, dbFloor };
+}
+
+function prepareCanvas(canvas, context, view) {
+  const rect = canvas.getBoundingClientRect();
+  const width = Math.max(1, rect.width || canvas.clientWidth || 720);
+  const height = Math.max(1, rect.height || canvas.clientHeight || width * 0.625);
+  const ratio = Math.min(MAX_PIXEL_RATIO, Math.max(1, Number(view.devicePixelRatio) || 1));
+  const pixelWidth = Math.max(1, Math.round(width * ratio));
+  const pixelHeight = Math.max(1, Math.round(height * ratio));
+  if (canvas.width !== pixelWidth || canvas.height !== pixelHeight) {
+    canvas.width = pixelWidth;
+    canvas.height = pixelHeight;
+  }
+  context.setTransform(ratio, 0, 0, ratio, 0, 0);
+  context.clearRect(0, 0, width, height);
+  return { width, height };
+}
+
+function unitDirection(azimuthDeg, elevationDeg) {
+  const azimuth = Number(azimuthDeg) * Math.PI / 180;
+  const elevation = Number(elevationDeg) * Math.PI / 180;
+  const horizontal = Math.cos(elevation);
+  return [
+    horizontal * Math.cos(azimuth),
+    horizontal * Math.sin(azimuth),
+    Math.sin(elevation),
+  ];
+}
+
+function rotatedPoint(point, yaw, pitch) {
+  const cosYaw = Math.cos(yaw);
+  const sinYaw = Math.sin(yaw);
+  const xYaw = cosYaw * point[0] - sinYaw * point[1];
+  const yYaw = sinYaw * point[0] + cosYaw * point[1];
+  const cosPitch = Math.cos(pitch);
+  const sinPitch = Math.sin(pitch);
+  return [
+    xYaw,
+    point[2] * cosPitch + yYaw * sinPitch,
+    point[2] * sinPitch - yYaw * cosPitch,
+  ];
+}
+
+function projectedPoint(point, yaw, pitch, size) {
+  const rotated = rotatedPoint(point, yaw, pitch);
+  const perspective = 1 / Math.max(0.68, 1 - rotated[2] * 0.18);
+  const scale = Math.min(size.width, size.height) * 0.39;
+  return {
+    x: size.width / 2 + rotated[0] * scale * perspective,
+    y: size.height / 2 - rotated[1] * scale * perspective,
+    depth: rotated[2],
+  };
+}
+
+function polygonArea(points) {
+  let area = 0;
+  for (let index = 0; index < points.length; index += 1) {
+    const current = points[index];
+    const next = points[(index + 1) % points.length];
+    area += current.x * next.y - next.x * current.y;
+  }
+  return Math.abs(area) / 2;
+}
+
+export function createReceiveBeamPatternSurfaceView(canvas) {
+  if (!canvas?.getContext) {
+    throw new TypeError("3D 빔 패턴 canvas가 필요합니다.");
+  }
+  const context = canvas.getContext("2d", { alpha: false });
+  if (!context) throw new Error("3D 빔 패턴 2D drawing context를 만들 수 없습니다.");
+  const view = canvas.ownerDocument?.defaultView ?? globalThis;
+  const requestFrame = view.requestAnimationFrame?.bind(view) ??
+    ((callback) => view.setTimeout(callback, 16));
+  const cancelFrame = view.cancelAnimationFrame?.bind(view) ?? view.clearTimeout?.bind(view);
+  let surface = null;
+  let validation = null;
+  let errorMessage = "";
+  let yaw = DEFAULT_YAW_RAD;
+  let pitch = DEFAULT_PITCH_RAD;
+  let orbit = null;
+  let frameId = 0;
+  let destroyed = false;
+
+  function schedule() {
+    if (!destroyed && !frameId) frameId = requestFrame(draw);
+  }
+
+  function drawMessage(size, message) {
+    context.fillStyle = "#07110f";
+    context.fillRect(0, 0, size.width, size.height);
+    context.fillStyle = "#ffc1bd";
+    context.font = "650 13px system-ui, sans-serif";
+    context.textAlign = "center";
+    context.textBaseline = "middle";
+    context.fillText(message, size.width / 2, size.height / 2);
+  }
+
+  function drawAxis(size, vector, color, label) {
+    const start = projectedPoint([0, 0, 0], yaw, pitch, size);
+    const end = projectedPoint(vector.map((value) => value * 1.18), yaw, pitch, size);
+    context.strokeStyle = color;
+    context.fillStyle = color;
+    context.lineWidth = 1.6;
+    context.beginPath();
+    context.moveTo(start.x, start.y);
+    context.lineTo(end.x, end.y);
+    context.stroke();
+    context.font = "750 11px ui-monospace, SFMono-Regular, Consolas, monospace";
+    context.textAlign = "center";
+    context.textBaseline = "middle";
+    context.fillText(label, end.x, end.y - 10);
+  }
+
+  function draw() {
+    frameId = 0;
+    if (destroyed) return;
+    const size = prepareCanvas(canvas, context, view);
+    context.fillStyle = "#07110f";
+    context.fillRect(0, 0, size.width, size.height);
+    if (errorMessage) {
+      drawMessage(size, errorMessage);
+      return;
+    }
+    if (!surface || !validation) {
+      drawMessage(size, "3D 빔 패턴을 계산하고 있습니다.");
+      return;
+    }
+
+    const { azimuthAxisDeg, elevationAxisDeg, displayDb, rows, columns, dbFloor } =
+      validation;
+    const vertices = new Array(rows * columns);
+    for (let row = 0; row < rows; row += 1) {
+      for (let column = 0; column < columns; column += 1) {
+        const index = row * columns + column;
+        const level = clamp((Number(displayDb[index]) - dbFloor) / -dbFloor, 0, 1);
+        const direction = unitDirection(azimuthAxisDeg[column], elevationAxisDeg[row]);
+        const point = direction.map((value) => value * level);
+        vertices[index] = { ...projectedPoint(point, yaw, pitch, size), level };
+      }
+    }
+
+    const faces = [];
+    for (let row = 0; row < rows - 1; row += 1) {
+      for (let column = 0; column < columns; column += 1) {
+        const nextColumn = (column + 1) % columns;
+        const points = [
+          vertices[row * columns + column],
+          vertices[row * columns + nextColumn],
+          vertices[(row + 1) * columns + nextColumn],
+          vertices[(row + 1) * columns + column],
+        ];
+        if (polygonArea(points) < 0.08) continue;
+        faces.push({
+          points,
+          depth: points.reduce((sum, point) => sum + point.depth, 0) / points.length,
+          level: points.reduce((sum, point) => sum + point.level, 0) / points.length,
+        });
+      }
+    }
+    faces.sort((left, right) => left.depth - right.depth);
+    for (const face of faces) {
+      context.beginPath();
+      context.moveTo(face.points[0].x, face.points[0].y);
+      for (let index = 1; index < face.points.length; index += 1) {
+        context.lineTo(face.points[index].x, face.points[index].y);
+      }
+      context.closePath();
+      context.fillStyle = surfaceColor(face.level);
+      context.fill();
+      context.strokeStyle = "rgba(218,245,236,.075)";
+      context.lineWidth = 0.55;
+      context.stroke();
+    }
+
+    const steeringDirection = Array.isArray(surface.steeringDirection)
+      ? surface.steeringDirection
+      : unitDirection(surface.steeringAzimuthDeg ?? 0, surface.steeringElevationDeg ?? 90);
+    const origin = projectedPoint([0, 0, 0], yaw, pitch, size);
+    const steeringEnd = projectedPoint(
+      steeringDirection.map((value) => Number(value) * 1.12),
+      yaw,
+      pitch,
+      size,
+    );
+    context.save();
+    context.setLineDash([7, 5]);
+    context.strokeStyle = "#ffc56e";
+    context.lineWidth = 2;
+    context.beginPath();
+    context.moveTo(origin.x, origin.y);
+    context.lineTo(steeringEnd.x, steeringEnd.y);
+    context.stroke();
+    context.restore();
+
+    drawAxis(size, [1, 0, 0], "#ff8f85", "+X");
+    drawAxis(size, [0, 1, 0], "#58c7e8", "+Y");
+    drawAxis(size, [0, 0, 1], "#65f2bf", "+Z FRONT");
+
+    context.fillStyle = "rgba(7,17,15,.82)";
+    context.fillRect(12, 12, 190, 42);
+    context.fillStyle = "#dceee8";
+    context.font = "700 12px ui-monospace, SFMono-Regular, Consolas, monospace";
+    context.textAlign = "left";
+    context.textBaseline = "top";
+    context.fillText(formatFrequency(Number(surface.frequencyHz)), 20, 20);
+    context.fillStyle = "#8eaaa0";
+    context.font = "600 10px ui-monospace, SFMono-Regular, Consolas, monospace";
+    context.fillText(columns + "×" + rows + " raw sphere samples", 20, 38);
+
+    const legendX = 16;
+    const legendY = size.height - 26;
+    const legendWidth = Math.min(170, size.width * 0.3);
+    for (let index = 0; index < 32; index += 1) {
+      const level = index / 31;
+      context.fillStyle = surfaceColor(level, 1);
+      context.fillRect(legendX + legendWidth * level, legendY, legendWidth / 31 + 1, 7);
+    }
+    context.fillStyle = "#9bb4ab";
+    context.font = "600 9px ui-monospace, SFMono-Regular, Consolas, monospace";
+    context.textBaseline = "bottom";
+    context.fillText(String(dbFloor) + " dB", legendX, legendY - 2);
+    context.textAlign = "right";
+    context.fillText("0 dB", legendX + legendWidth, legendY - 2);
+  }
+
+  function render(nextSurface) {
+    if (destroyed) return;
+    try {
+      validation = validateSurface(nextSurface);
+      surface = nextSurface;
+      errorMessage = "";
+      canvas.dataset.sampleCount = String(validation.rows * validation.columns);
+      canvas.dataset.frequencyHz = String(nextSurface.frequencyHz);
+      canvas.dataset.gridShape = validation.columns + "x" + validation.rows;
+    } catch (error) {
+      surface = null;
+      validation = null;
+      delete canvas.dataset.sampleCount;
+      delete canvas.dataset.frequencyHz;
+      delete canvas.dataset.gridShape;
+      errorMessage = error instanceof Error ? error.message : String(error);
+    }
+    schedule();
+  }
+
+  function renderError(message) {
+    surface = null;
+    validation = null;
+    delete canvas.dataset.sampleCount;
+    delete canvas.dataset.frequencyHz;
+    delete canvas.dataset.gridShape;
+    errorMessage = String(message || "3D 빔 패턴을 표시할 수 없습니다.");
+    schedule();
+  }
+
+  function finishOrbit(event) {
+    if (!orbit || (event?.pointerId !== undefined && event.pointerId !== orbit.pointerId)) return;
+    const pointerId = orbit.pointerId;
+    orbit = null;
+    delete canvas.dataset.orbiting;
+    try {
+      if (canvas.hasPointerCapture?.(pointerId)) canvas.releasePointerCapture?.(pointerId);
+    } catch {
+      // Pointer capture may already be released.
+    }
+  }
+
+  function onPointerDown(event) {
+    if (event.button !== 0 || orbit) return;
+    event.preventDefault();
+    try {
+      canvas.focus({ preventScroll: true });
+    } catch {
+      canvas.focus?.();
+    }
+    orbit = { pointerId: event.pointerId, x: event.clientX, y: event.clientY };
+    canvas.dataset.orbiting = "true";
+    try {
+      canvas.setPointerCapture?.(event.pointerId);
+    } catch {
+      // Synthetic pointers may not own capture.
+    }
+  }
+
+  function onPointerMove(event) {
+    if (!orbit || orbit.pointerId !== event.pointerId) return;
+    event.preventDefault();
+    yaw += (event.clientX - orbit.x) * 0.011;
+    pitch = clamp(
+      pitch - (event.clientY - orbit.y) * 0.011,
+      -MAX_PITCH_RAD,
+      MAX_PITCH_RAD,
+    );
+    orbit.x = event.clientX;
+    orbit.y = event.clientY;
+    schedule();
+  }
+
+  function onKeyDown(event) {
+    const step = event.shiftKey ? 15 : 5;
+    if (event.key === "ArrowLeft") yaw -= step * Math.PI / 180;
+    else if (event.key === "ArrowRight") yaw += step * Math.PI / 180;
+    else if (event.key === "ArrowUp") {
+      pitch = clamp(pitch + step * Math.PI / 180, -MAX_PITCH_RAD, MAX_PITCH_RAD);
+    } else if (event.key === "ArrowDown") {
+      pitch = clamp(pitch - step * Math.PI / 180, -MAX_PITCH_RAD, MAX_PITCH_RAD);
+    }
+    else if (event.key.toLowerCase() === "r") {
+      yaw = DEFAULT_YAW_RAD;
+      pitch = DEFAULT_PITCH_RAD;
+    } else return;
+    event.preventDefault();
+    schedule();
+  }
+
+  canvas.setAttribute("aria-keyshortcuts", "ArrowLeft ArrowRight ArrowUp ArrowDown R");
+  canvas.addEventListener("pointerdown", onPointerDown);
+  canvas.addEventListener("pointermove", onPointerMove);
+  canvas.addEventListener("pointerup", finishOrbit);
+  canvas.addEventListener("pointercancel", finishOrbit);
+  canvas.addEventListener("lostpointercapture", finishOrbit);
+  canvas.addEventListener("keydown", onKeyDown);
+  let resizeObserver = null;
+  const onResize = () => schedule();
+  if (typeof view.ResizeObserver === "function") {
+    resizeObserver = new view.ResizeObserver(onResize);
+    resizeObserver.observe(canvas);
+  } else {
+    view.addEventListener?.("resize", onResize);
+  }
+  schedule();
+
+  return {
+    render,
+    renderError,
+    resetOrbit() {
+      yaw = DEFAULT_YAW_RAD;
+      pitch = DEFAULT_PITCH_RAD;
+      schedule();
+    },
+    destroy() {
+      if (destroyed) return;
+      destroyed = true;
+      if (frameId) cancelFrame?.(frameId);
+      resizeObserver?.disconnect();
+      view.removeEventListener?.("resize", onResize);
+      canvas.removeEventListener("pointerdown", onPointerDown);
+      canvas.removeEventListener("pointermove", onPointerMove);
+      canvas.removeEventListener("pointerup", finishOrbit);
+      canvas.removeEventListener("pointercancel", finishOrbit);
+      canvas.removeEventListener("lostpointercapture", finishOrbit);
+      canvas.removeEventListener("keydown", onKeyDown);
+      surface = null;
+      validation = null;
+      orbit = null;
+    },
+  };
+}
diff --git a/apps/array-builder/canvas-view.js b/apps/array-builder/canvas-view.js
index 870a4d3..521d3c2 100644
--- a/apps/array-builder/canvas-view.js
+++ b/apps/array-builder/canvas-view.js
@@ -7,6 +7,7 @@ const MIN_ZOOM = 0.25;
 const MAX_ZOOM = 16;
 const TOUCH_GESTURE_THRESHOLD_PX = 6;
 const DEFAULT_MARGINS = Object.freeze({ left: 54, right: 22, top: 30, bottom: 46 });
+const DEFAULT_ORBIT = Object.freeze({ yaw: -Math.PI / 5, pitch: Math.PI / 4.5 });
 
 export const ARRAY_CANVAS_TOOLS = Object.freeze(["select", "add"]);
 
@@ -21,8 +22,10 @@ function finiteNumber(value, fallback = 0) {
 
 function validPosition(position) {
   return Array.isArray(position) &&
+    position.length >= 3 &&
     Number.isFinite(Number(position[0])) &&
-    Number.isFinite(Number(position[1]));
+    Number.isFinite(Number(position[1])) &&
+    Number.isFinite(Number(position[2]));
 }
 
 function apertureDimensions(arrayDefinition) {
@@ -198,6 +201,89 @@ export function hitTestMicrophone(point, microphones, viewport, radiusPx = 12) {
   return best;
 }
 
+function rotateArrayPosition3d(position, yaw, pitch) {
+  const x = finiteNumber(position?.[0]);
+  const y = finiteNumber(position?.[1]);
+  const z = finiteNumber(position?.[2]);
+  const cosYaw = Math.cos(yaw);
+  const sinYaw = Math.sin(yaw);
+  const cosPitch = Math.cos(pitch);
+  const sinPitch = Math.sin(pitch);
+  const horizontal = cosYaw * x - sinYaw * y;
+  const away = sinYaw * x + cosYaw * y;
+  return {
+    horizontal,
+    vertical: z * cosPitch + away * sinPitch,
+    depth: z * sinPitch - away * cosPitch,
+  };
+}
+
+/** Project an array [x,y,z] position into a fitted 3D inspection viewport. */
+export function projectArrayPosition3d(position, viewport) {
+  const rotated = rotateArrayPosition3d(position, viewport.yaw, viewport.pitch);
+  return {
+    x: viewport.centerPixelX + (rotated.horizontal - viewport.centerHorizontal) * viewport.scale,
+    y: viewport.centerPixelY - (rotated.vertical - viewport.centerVertical) * viewport.scale,
+    depth: rotated.depth,
+  };
+}
+
+function fitArrayViewport3d(width, height, model, zoom, orbit) {
+  const canvasWidth = Math.max(1, finiteNumber(width, 1));
+  const canvasHeight = Math.max(1, finiteNumber(height, 1));
+  const margins = resolvedMargins(canvasWidth, canvasHeight, {
+    left: 32,
+    right: 32,
+    top: 45,
+    bottom: 38,
+  });
+  const plot = {
+    x: margins.left,
+    y: margins.top,
+    width: Math.max(1, canvasWidth - margins.left - margins.right),
+    height: Math.max(1, canvasHeight - margins.top - margins.bottom),
+  };
+  const aperture = apertureDimensions(model.arrayDefinition);
+  const referenceSpan = Math.max(aperture.width, aperture.height, 0.000001);
+  const points = [
+    [-aperture.width / 2, -aperture.height / 2, 0],
+    [aperture.width / 2, -aperture.height / 2, 0],
+    [aperture.width / 2, aperture.height / 2, 0],
+    [-aperture.width / 2, aperture.height / 2, 0],
+    [0, 0, referenceSpan * 0.72],
+  ];
+  for (const microphone of model.arrayDefinition.microphones ?? []) {
+    if (validPosition(microphone?.position)) points.push(microphone.position);
+  }
+  const rotated = points.map((position) => rotateArrayPosition3d(position, orbit.yaw, orbit.pitch));
+  const horizontalValues = rotated.map((point) => point.horizontal);
+  const verticalValues = rotated.map((point) => point.vertical);
+  const horizontalMin = Math.min(...horizontalValues);
+  const horizontalMax = Math.max(...horizontalValues);
+  const verticalMin = Math.min(...verticalValues);
+  const verticalMax = Math.max(...verticalValues);
+  const horizontalSpan = Math.max(0.000001, horizontalMax - horizontalMin);
+  const verticalSpan = Math.max(0.000001, verticalMax - verticalMin);
+  const scale = Math.max(
+    Number.MIN_VALUE,
+    Math.min(plot.width / (horizontalSpan * 1.22), plot.height / (verticalSpan * 1.22)) * zoom,
+  );
+  return {
+    width: canvasWidth,
+    height: canvasHeight,
+    plot,
+    scale,
+    zoom,
+    yaw: orbit.yaw,
+    pitch: orbit.pitch,
+    centerHorizontal: (horizontalMin + horizontalMax) / 2,
+    centerVertical: (verticalMin + verticalMax) / 2,
+    centerPixelX: plot.x + plot.width / 2,
+    centerPixelY: plot.y + plot.height / 2,
+    referenceSpan,
+  };
+}
+
 /** Pure keyboard-to-array delta mapping used by the canvas controller. */
 export function keyboardNudgeForKey(key, stepM = 0.001, shiftKey = false) {
   const requestedStep = Math.abs(finiteNumber(stepM, 0.001));
@@ -444,9 +530,233 @@ function drawArray(context, size, model, zoom, drag) {
   context.textBaseline = "top";
   context.fillText(Math.round(zoom * 100) + "%", viewport.plot.x + viewport.plot.width, 8);
   context.textAlign = "left";
+  context.textBaseline = "top";
+  context.fillStyle = "rgba(101,242,191,.88)";
+  context.font = "700 10px ui-monospace, SFMono-Regular, Consolas, monospace";
+  context.beginPath();
+  context.arc(viewport.plot.x + 10, viewport.plot.y + 11, 5, 0, Math.PI * 2);
+  context.stroke();
+  context.beginPath();
+  context.arc(viewport.plot.x + 10, viewport.plot.y + 11, 1.8, 0, Math.PI * 2);
+  context.fill();
+  context.fillText("+Z FRONT", viewport.plot.x + 20, viewport.plot.y + 5);
+  context.textAlign = "left";
   return viewport;
 }
 
+function traceProjectedPositions(context, positions, viewport, close = false) {
+  context.beginPath();
+  positions.forEach((position, index) => {
+    const point = projectArrayPosition3d(position, viewport);
+    if (index === 0) context.moveTo(point.x, point.y);
+    else context.lineTo(point.x, point.y);
+  });
+  if (close) context.closePath();
+}
+
+function aperturePerimeter3d(model, sampleCount = 72) {
+  const aperture = apertureDimensions(model.arrayDefinition);
+  if (model.apertureShape !== "ellipse") {
+    return [
+      [-aperture.width / 2, -aperture.height / 2, 0],
+      [aperture.width / 2, -aperture.height / 2, 0],
+      [aperture.width / 2, aperture.height / 2, 0],
+      [-aperture.width / 2, aperture.height / 2, 0],
+    ];
+  }
+  return Array.from({ length: sampleCount }, (_, index) => {
+    const angle = index / sampleCount * Math.PI * 2;
+    return [
+      Math.cos(angle) * aperture.width / 2,
+      Math.sin(angle) * aperture.height / 2,
+      0,
+    ];
+  });
+}
+
+function drawProjectedLine(context, start, end, viewport) {
+  const a = projectArrayPosition3d(start, viewport);
+  const b = projectArrayPosition3d(end, viewport);
+  context.beginPath();
+  context.moveTo(a.x, a.y);
+  context.lineTo(b.x, b.y);
+  context.stroke();
+  return b;
+}
+
+function drawArrayPlane3d(context, model, viewport) {
+  const perimeter = aperturePerimeter3d(model);
+  traceProjectedPositions(context, perimeter, viewport, true);
+  context.fillStyle = "rgba(101,242,191,.055)";
+  context.fill();
+  context.strokeStyle = "rgba(174,229,210,.72)";
+  context.lineWidth = 1.5;
+  context.setLineDash([7, 5]);
+  context.stroke();
+  context.setLineDash([]);
+
+  const aperture = apertureDimensions(model.arrayDefinition);
+  context.strokeStyle = "rgba(166,196,186,.14)";
+  context.lineWidth = 1;
+  for (const fraction of [-0.75, -0.5, -0.25, 0, 0.25, 0.5, 0.75]) {
+    if (model.apertureShape === "ellipse") {
+      const bound = Math.sqrt(Math.max(0, 1 - fraction * fraction));
+      drawProjectedLine(
+        context,
+        [fraction * aperture.width / 2, -bound * aperture.height / 2, 0],
+        [fraction * aperture.width / 2, bound * aperture.height / 2, 0],
+        viewport,
+      );
+      drawProjectedLine(
+        context,
+        [-bound * aperture.width / 2, fraction * aperture.height / 2, 0],
+        [bound * aperture.width / 2, fraction * aperture.height / 2, 0],
+        viewport,
+      );
+    } else {
+      drawProjectedLine(
+        context,
+        [fraction * aperture.width / 2, -aperture.height / 2, 0],
+        [fraction * aperture.width / 2, aperture.height / 2, 0],
+        viewport,
+      );
+      drawProjectedLine(
+        context,
+        [-aperture.width / 2, fraction * aperture.height / 2, 0],
+        [aperture.width / 2, fraction * aperture.height / 2, 0],
+        viewport,
+      );
+    }
+  }
+}
+
+function drawAxis3d(context, viewport, endpoint, color, label) {
+  context.strokeStyle = color;
+  context.fillStyle = color;
+  context.lineWidth = 2;
+  const point = drawProjectedLine(context, [0, 0, 0], endpoint, viewport);
+  context.beginPath();
+  context.arc(point.x, point.y, 3, 0, Math.PI * 2);
+  context.fill();
+  context.font = "800 10px ui-monospace, SFMono-Regular, Consolas, monospace";
+  context.textAlign = "left";
+  context.textBaseline = "middle";
+  context.fillText(label, point.x + 6, point.y);
+}
+
+function drawAxes3d(context, model, viewport) {
+  const aperture = apertureDimensions(model.arrayDefinition);
+  drawAxis3d(context, viewport, [aperture.width * 0.58, 0, 0], "#ff9e75", "+X");
+  drawAxis3d(context, viewport, [0, aperture.height * 0.58, 0], "#76b9ff", "+Y");
+  drawAxis3d(
+    context,
+    viewport,
+    [0, 0, viewport.referenceSpan * 0.72],
+    "#65f2bf",
+    "+Z FRONT",
+  );
+}
+
+function projectedMicrophones(model, viewport) {
+  return (model.arrayDefinition.microphones ?? [])
+    .filter((microphone) => validPosition(microphone?.position))
+    .map((microphone, index) => ({
+      microphone,
+      index,
+      point: projectArrayPosition3d(microphone.position, viewport),
+    }))
+    .sort((left, right) => left.point.depth - right.point.depth);
+}
+
+function drawMicrophones3d(context, model, viewport) {
+  const microphones = projectedMicrophones(model, viewport);
+  const baseRadius = clamp(8 - Math.log2(Math.max(1, microphones.length)) * 0.55, 3, 7);
+  let selected = null;
+  for (const item of microphones) {
+    const { microphone, point } = item;
+    const isSelected = microphone.id === model.selectedMicrophoneId;
+    const inside = positionInsideAperture(
+      microphone.position,
+      model.arrayDefinition.aperture,
+      model.apertureShape,
+    );
+    const radius = isSelected ? Math.max(7, baseRadius + 2) : baseRadius;
+    context.fillStyle = inside ? "rgba(101,242,191,.96)" : "rgba(255,184,92,.98)";
+    context.shadowColor = inside ? "rgba(101,242,191,.7)" : "rgba(255,184,92,.7)";
+    context.shadowBlur = isSelected ? 16 : microphones.length > 256 ? 0 : 6;
+    context.beginPath();
+    context.arc(point.x, point.y, radius, 0, Math.PI * 2);
+    context.fill();
+    context.shadowBlur = 0;
+    context.strokeStyle = "rgba(239,255,249,.7)";
+    context.lineWidth = 1;
+    context.stroke();
+    if (isSelected) selected = { microphone, point, radius };
+  }
+  if (selected) {
+    context.strokeStyle = "rgba(255,255,255,.94)";
+    context.lineWidth = 2;
+    context.beginPath();
+    context.arc(selected.point.x, selected.point.y, selected.radius + 6, 0, Math.PI * 2);
+    context.stroke();
+    drawSelectedLabel(context, selected.microphone, selected.point, viewport);
+  }
+  return microphones;
+}
+
+function drawArray3d(context, size, model, zoom, orbit) {
+  context.fillStyle = BACKGROUND;
+  context.fillRect(0, 0, size.width, size.height);
+  if (!model?.arrayDefinition?.aperture || !Array.isArray(model.arrayDefinition.microphones)) {
+    drawEmpty(context, size.width, size.height);
+    return null;
+  }
+  const viewport = fitArrayViewport3d(size.width, size.height, model, zoom, orbit);
+  context.fillStyle = PLOT_BACKGROUND;
+  context.fillRect(viewport.plot.x, viewport.plot.y, viewport.plot.width, viewport.plot.height);
+  context.save();
+  context.beginPath();
+  context.rect(viewport.plot.x, viewport.plot.y, viewport.plot.width, viewport.plot.height);
+  context.clip();
+  drawArrayPlane3d(context, model, viewport);
+  drawAxes3d(context, model, viewport);
+  viewport.projectedMicrophones = drawMicrophones3d(context, model, viewport);
+  context.restore();
+
+  context.strokeStyle = "rgba(174,211,199,.28)";
+  context.lineWidth = 1;
+  context.strokeRect(
+    viewport.plot.x + 0.5,
+    viewport.plot.y + 0.5,
+    Math.max(0, viewport.plot.width - 1),
+    Math.max(0, viewport.plot.height - 1),
+  );
+  context.font = "700 10px ui-monospace, SFMono-Regular, Consolas, monospace";
+  context.textBaseline = "top";
+  context.fillStyle = "rgba(205,225,218,.72)";
+  context.textAlign = "left";
+  context.fillText("3D INSPECT - drag to orbit", viewport.plot.x, 8);
+  context.textAlign = "right";
+  context.fillText(Math.round(zoom * 100) + "%", viewport.plot.x + viewport.plot.width, 8);
+  context.textAlign = "left";
+  return viewport;
+}
+
+function hitTestProjectedMicrophone(point, model, viewport, radiusPx = 12) {
+  let best = null;
+  for (const item of viewport?.projectedMicrophones ?? projectedMicrophones(model, viewport)) {
+    const distancePx = Math.hypot(item.point.x - point.x, item.point.y - point.y);
+    const isCloser = !best || distancePx < best.distancePx - 1e-9;
+    const isNearerTie = best &&
+      Math.abs(distancePx - best.distancePx) <= 1e-9 &&
+      item.point.depth > best.point.depth;
+    if (distancePx <= radiusPx && (isCloser || isNearerTie)) {
+      best = { ...item, id: item.microphone.id, distancePx };
+    }
+  }
+  return best;
+}
+
 function normalizedTool(tool) {
   return ARRAY_CANVAS_TOOLS.includes(tool) ? tool : "select";
 }
@@ -471,6 +781,9 @@ export function createArrayCanvas(canvas, callbacks = {}) {
   let destroyed = false;
   let zoom = 1;
   let tool = "select";
+  let viewMode = "2d";
+  let orbit = { ...DEFAULT_ORBIT };
+  let orbitDrag = null;
   let drag = null;
   let pendingAdd = null;
 
@@ -479,15 +792,23 @@ export function createArrayCanvas(canvas, callbacks = {}) {
     if (canvas.dataset) {
       canvas.dataset.tool = tool;
       canvas.dataset.zoom = String(zoom);
+      canvas.dataset.viewMode = viewMode;
+      canvas.dataset.orbiting = String(Boolean(orbitDrag));
+    }
+    if (canvas.style) {
+      canvas.style.cursor = viewMode === "3d"
+        ? orbitDrag ? "grabbing" : "grab"
+        : tool === "add" ? "crosshair" : drag ? "grabbing" : "default";
     }
-    if (canvas.style) canvas.style.cursor = tool === "add" ? "crosshair" : drag ? "grabbing" : "default";
   }
 
   function drawCurrent() {
     frameId = 0;
     if (destroyed) return;
     const size = prepareContext(canvas, context, view);
-    viewport = drawArray(context, size, model, zoom, drag);
+    viewport = viewMode === "3d"
+      ? drawArray3d(context, size, model, zoom, orbit)
+      : drawArray(context, size, model, zoom, drag);
     updateCanvasAffordance();
   }
 
@@ -499,20 +820,30 @@ export function createArrayCanvas(canvas, callbacks = {}) {
     if (viewport) return viewport;
     if (!model?.arrayDefinition) return null;
     const rect = canvas.getBoundingClientRect();
-    viewport = fitArrayViewport(rect.width, rect.height, model.arrayDefinition, { zoom });
+    viewport = viewMode === "3d"
+      ? fitArrayViewport3d(rect.width, rect.height, model, zoom, orbit)
+      : fitArrayViewport(rect.width, rect.height, model.arrayDefinition, { zoom });
     return viewport;
   }
 
   function render(nextModel) {
     if (destroyed) return;
     model = nextModel;
+    const nextViewMode = nextModel?.viewMode === "3d" ? "3d" : "2d";
+    if (viewMode !== nextViewMode) {
+      viewMode = nextViewMode;
+      drag = null;
+      pendingAdd = null;
+      orbitDrag = null;
+    }
     tool = normalizedTool(nextModel?.tool ?? tool);
+    if (viewMode === "3d") tool = "select";
     viewport = null;
     schedule();
   }
 
   function setTool(nextTool) {
-    const resolved = normalizedTool(nextTool);
+    const resolved = viewMode === "3d" ? "select" : normalizedTool(nextTool);
     if (resolved === tool) return tool;
     if (resolved !== "add") pendingAdd = null;
     tool = resolved;
@@ -524,6 +855,7 @@ export function createArrayCanvas(canvas, callbacks = {}) {
 
   function fit() {
     zoom = 1;
+    if (viewMode === "3d") orbit = { ...DEFAULT_ORBIT };
     viewport = null;
     schedule();
     return zoom;
@@ -586,8 +918,29 @@ export function createArrayCanvas(canvas, callbacks = {}) {
       TOUCH_GESTURE_THRESHOLD_PX;
   }
 
+  function finishOrbit(event) {
+    if (!orbitDrag || (event?.pointerId !== undefined && event.pointerId !== orbitDrag.pointerId)) {
+      return false;
+    }
+    const pointerId = event?.pointerId ?? orbitDrag.pointerId;
+    orbitDrag = null;
+    try {
+      if (canvas.hasPointerCapture?.(pointerId)) canvas.releasePointerCapture?.(pointerId);
+    } catch {
+      // Capture can be released by the browser before cancellation arrives.
+    }
+    updateCanvasAffordance();
+    schedule();
+    return true;
+  }
+
   function onTouchStart(event) {
-    if (destroyed || tool !== "select" || !model?.arrayDefinition) return;
+    if (destroyed || !model?.arrayDefinition) return;
+    if (viewMode === "3d") {
+      event.preventDefault();
+      return;
+    }
+    if (tool !== "select") return;
     const touch = event.changedTouches?.[0] ?? event.touches?.[0];
     const currentViewport = ensureViewport();
     if (!touch || !currentViewport) return;
@@ -601,8 +954,27 @@ export function createArrayCanvas(canvas, callbacks = {}) {
 
   function onPointerDown(event) {
     if (destroyed || event.button !== 0 || !model?.arrayDefinition) return;
-    if (drag || pendingAdd) return;
+    if (drag || pendingAdd || orbitDrag) return;
     focus();
+    if (viewMode === "3d") {
+      event.preventDefault();
+      const currentViewport = ensureViewport();
+      if (!currentViewport) return;
+      const hit = hitTestProjectedMicrophone(pointerPoint(event), model, currentViewport);
+      callbacks.onSelect?.(hit?.id ?? null);
+      orbitDrag = {
+        pointerId: event.pointerId,
+        lastClient: clientPoint(event),
+      };
+      try {
+        canvas.setPointerCapture?.(event.pointerId);
+      } catch {
+        // Synthetic pointers and interrupted input do not always own capture.
+      }
+      updateCanvasAffordance();
+      schedule();
+      return;
+    }
     if (tool === "add") {
       const position = constrainedEventPosition(event, 0);
       if (position) {
@@ -649,6 +1021,18 @@ export function createArrayCanvas(canvas, callbacks = {}) {
   }
 
   function onPointerMove(event) {
+    if (orbitDrag?.pointerId === event.pointerId) {
+      const current = clientPoint(event);
+      const dx = current.x - orbitDrag.lastClient.x;
+      const dy = current.y - orbitDrag.lastClient.y;
+      orbitDrag.lastClient = current;
+      orbit.yaw += dx * 0.01;
+      orbit.pitch = clamp(orbit.pitch - dy * 0.01, -Math.PI * 0.46, Math.PI * 0.46);
+      viewport = null;
+      event.preventDefault();
+      schedule();
+      return;
+    }
     if (pendingAdd?.pointerId === event.pointerId) {
       if (exceedsTouchThreshold(pendingAdd.startClient, event)) pendingAdd = null;
       return;
@@ -705,6 +1089,39 @@ export function createArrayCanvas(canvas, callbacks = {}) {
 
   function onKeyDown(event) {
     if (event.altKey || event.ctrlKey || event.metaKey) return;
+    if (viewMode === "3d") {
+      const key = event.key.length === 1 ? event.key.toLowerCase() : event.key;
+      if (key === "f" || key === "r") {
+        event.preventDefault();
+        fit();
+        callbacks.onFit?.();
+        return;
+      }
+      if (event.key === "Escape") {
+        event.preventDefault();
+        finishOrbit();
+        return;
+      }
+      const orbitStep = event.shiftKey ? 0.18 : 0.06;
+      if (event.key === "ArrowLeft" || event.key === "ArrowRight") {
+        event.preventDefault();
+        orbit.yaw += event.key === "ArrowLeft" ? -orbitStep : orbitStep;
+        viewport = null;
+        schedule();
+        return;
+      }
+      if (event.key === "ArrowUp" || event.key === "ArrowDown") {
+        event.preventDefault();
+        orbit.pitch = clamp(
+          orbit.pitch + (event.key === "ArrowUp" ? orbitStep : -orbitStep),
+          -Math.PI * 0.46,
+          Math.PI * 0.46,
+        );
+        viewport = null;
+        schedule();
+      }
+      return;
+    }
     const lowerKey = event.key.length === 1 ? event.key.toLowerCase() : event.key;
     if (lowerKey === "a") {
       event.preventDefault();
@@ -742,16 +1159,22 @@ export function createArrayCanvas(canvas, callbacks = {}) {
   }
 
   function onPointerUp(event) {
+    if (finishOrbit(event)) return;
     if (finishPendingAdd(event, false)) return;
     finishDrag(event, false);
   }
 
   function onPointerCancel(event) {
+    if (finishOrbit(event)) return;
     if (finishPendingAdd(event, true)) return;
     finishDrag(event, true);
   }
 
   function onLostPointerCapture(event) {
+    if (orbitDrag?.pointerId === event.pointerId) {
+      finishOrbit(event);
+      return;
+    }
     if (drag?.pointerId === event.pointerId) finishDrag(event, false);
   }
 
@@ -798,6 +1221,7 @@ export function createArrayCanvas(canvas, callbacks = {}) {
       canvas.removeEventListener("keydown", onKeyDown);
       model = null;
       viewport = null;
+      orbitDrag = null;
       drag = null;
       pendingAdd = null;
     },
diff --git a/apps/array-builder/index.html b/apps/array-builder/index.html
index 7158485..1deff39 100644
--- a/apps/array-builder/index.html
+++ b/apps/array-builder/index.html
@@ -44,7 +44,7 @@
           <div class="workspace-heading">
             <div>
               <p class="eyebrow">마이크 배치</p>
-              <h1>Array 평면 편집</h1>
+              <h1>Array 2D 편집 · 3D 검사</h1>
             </div>
             <p class="workspace-summary" id="workspace-summary">0.45 × 0.45 m · 12 channels</p>
           </div>
@@ -54,6 +54,10 @@
               <button class="tool-button is-active" id="select-tool-button" type="button" aria-pressed="true" aria-keyshortcuts="V">선택 <kbd>V</kbd></button>
               <button class="tool-button" id="add-tool-button" type="button" aria-pressed="false" aria-keyshortcuts="A">추가 <kbd>A</kbd></button>
             </div>
+            <div class="toolbar-group array-view-toggle" role="group" aria-label="배열 보기 방식">
+              <button class="tool-button is-active" id="array-view-2d-button" type="button" aria-pressed="true">2D 편집</button>
+              <button class="tool-button" id="array-view-3d-button" type="button" aria-pressed="false">3D 검사</button>
+            </div>
             <div class="toolbar-group" aria-label="실행 취소와 다시 실행">
               <button class="tool-button" id="undo-button" type="button" aria-keyshortcuts="Control+Z" disabled>실행 취소</button>
               <button class="tool-button" id="redo-button" type="button" aria-keyshortcuts="Control+Shift+Z" disabled>다시 실행</button>
@@ -80,6 +84,7 @@
               <strong>마이크를 클릭하거나 드래그해 위치를 편집하세요.</strong>
               <span>추가 도구에서는 빈 공간을 클릭해 새 채널을 만듭니다.</span>
             </div>
+            <div class="canvas-front-badge" id="canvas-front-badge">+Z FRONT · 화면 바깥쪽</div>
             <div class="selection-status" id="selection-status" role="status" aria-live="polite">선택된 마이크 없음</div>
           </div>
 
@@ -96,7 +101,7 @@
                 <p class="eyebrow">배열 분석</p>
                 <h2>수신 빔 패턴</h2>
               </div>
-              <span id="beam-pattern-summary">1 kHz · XZ · +Z 조향</span>
+              <span id="beam-pattern-summary">1 kHz · XZ/YZ/XY 동시</span>
             </summary>
 
             <div class="beam-pattern-body">
@@ -106,18 +111,30 @@
                   <span>geometry-only</span>
                 </p>
 
+                <div class="beam-pattern-view-switch" role="group" aria-label="빔 패턴 보기 방식">
+                  <button class="tool-button is-active" id="beam-pattern-view-cuts-button" type="button" aria-pressed="true">세 평면</button>
+                  <button class="tool-button" id="beam-pattern-view-3d-button" type="button" aria-pressed="false">3D 표면</button>
+                </div>
+
                 <div class="beam-pattern-fields">
-                  <label class="field">
-                    <span>아날로그 주파수 (Hz)</span>
-                    <input
-                      id="beam-pattern-frequency"
-                      type="number"
-                      min="1"
-                      max="1000000"
-                      step="100"
-                      value="1000"
-                      inputmode="decimal"
-                    />
+                  <label class="field beam-frequency-field">
+                    <span>아날로그 주파수 · 로그 슬라이더</span>
+                    <div class="beam-frequency-control">
+                      <input
+                        id="beam-pattern-frequency"
+                        type="range"
+                        min="0"
+                        max="6000"
+                        step="1"
+                        value="3000"
+                        aria-valuemin="1"
+                        aria-valuemax="1000000"
+                        aria-valuenow="1000"
+                        aria-valuetext="1.000 kHz"
+                      />
+                      <output id="beam-pattern-frequency-value" for="beam-pattern-frequency">1.000 kHz</output>
+                    </div>
+                    <small>1 Hz–1 MHz · 이동 중 live preview</small>
                   </label>
                   <label class="field">
                     <span>음속 (m/s)</span>
@@ -131,16 +148,8 @@
                       inputmode="decimal"
                     />
                   </label>
-                  <label class="field">
-                    <span>360° 절단면</span>
-                    <select id="beam-pattern-cut">
-                      <option value="xz">XZ · 0° +Z / 90° +X</option>
-                      <option value="yz">YZ · 0° +Z / 90° +Y</option>
-                      <option value="xy">XY · 0° +X / 90° +Y</option>
-                    </select>
-                  </label>
-                  <label class="field">
-                    <span>조향각 (deg)</span>
+                  <label class="field" data-beam-mode="cuts">
+                    <span>단면별 조향각 (deg)</span>
                     <input
                       id="beam-pattern-steering-angle"
                       type="number"
@@ -150,8 +159,9 @@
                       value="0"
                       inputmode="decimal"
                     />
+                    <small>각 XZ/YZ/XY 평면 안에서 독립 조향</small>
                   </label>
-                  <label class="field">
+                  <label class="field" data-beam-mode="cuts">
                     <span>각도 샘플</span>
                     <select id="beam-pattern-samples">
                       <option value="auto">자동 · 위상 간격 기준</option>
@@ -162,6 +172,24 @@
                       <option value="5760">5,760 · 0.0625°</option>
                     </select>
                   </label>
+                  <label class="field" data-beam-mode="surface" hidden>
+                    <span>3D 조향 방위각 (deg)</span>
+                    <input id="beam-pattern-steering-azimuth" type="number" min="-360" max="360" step="1" value="0" inputmode="decimal" />
+                    <small>XY에서 +X→+Y</small>
+                  </label>
+                  <label class="field" data-beam-mode="surface" hidden>
+                    <span>3D 조향 고도각 (deg)</span>
+                    <input id="beam-pattern-steering-elevation" type="number" min="-90" max="90" step="1" value="90" inputmode="decimal" />
+                    <small>+90°가 +Z FRONT</small>
+                  </label>
+                  <label class="field" data-beam-mode="surface" hidden>
+                    <span>3D 구면 표본</span>
+                    <select id="beam-pattern-surface-resolution">
+                      <option value="5">5° · 72×37</option>
+                      <option value="3" selected>3° · 120×61</option>
+                      <option value="2.5">2.5° · 144×73</option>
+                    </select>
+                  </label>
                   <label class="field">
                     <span>표시 하한 (dB)</span>
                     <select id="beam-pattern-floor">
@@ -185,24 +213,44 @@
                   현재 배열의 수신 array factor를 계산하고 있습니다.
                 </p>
                 <p class="beam-pattern-note" id="beam-pattern-model-note">
-                  이상적으로 보정된 무지향성 점 마이크의 자유장 평면파 단면입니다. 3D 전체 패턴,
-                  근거리, 방·하우징, 마이크 주파수 응답은 포함하지 않습니다. ADC가 없으므로
-                  Nyquist 초과 주파수도 접지 않고 원래 파장으로 계산합니다.
+                  이상적으로 보정된 무지향성 점 마이크의 자유장 평면파 응답입니다. 세 평면은 각각
+                  독립 조향한 great-circle 단면이며 3D 모드는 실제 구면 방향을 계산합니다. 근거리,
+                  방·하우징, 마이크 주파수 응답은 포함하지 않습니다. ADC가 없으므로 Nyquist 초과
+                  주파수도 접지 않고 원래 파장으로 계산합니다.
                 </p>
               </div>
 
-              <figure class="beam-pattern-figure">
-                <svg
-                  id="beam-pattern-plot"
-                  viewBox="0 0 520 520"
-                  role="img"
-                  aria-label="수신 빔 패턴 polar plot"
-                  aria-describedby="beam-pattern-status beam-pattern-model-note beam-pattern-peaks"
-                ></svg>
-                <figcaption id="beam-pattern-peaks">
-                  국소 최대를 계산하고 있습니다.
-                </figcaption>
-              </figure>
+              <div class="beam-pattern-visuals">
+                <div class="beam-pattern-cut-grid" id="beam-pattern-cuts-view">
+                  <figure class="beam-pattern-figure" data-cut="xz">
+                    <div class="beam-pattern-figure-heading"><strong>XZ</strong><span>0° +Z · 90° +X</span></div>
+                    <svg id="beam-pattern-plot-xz" viewBox="0 0 520 520" role="img" aria-label="XZ 수신 빔 패턴 polar plot" aria-describedby="beam-pattern-status beam-pattern-model-note beam-pattern-caption-xz"></svg>
+                    <figcaption id="beam-pattern-caption-xz">계산 중…</figcaption>
+                  </figure>
+                  <figure class="beam-pattern-figure" data-cut="yz">
+                    <div class="beam-pattern-figure-heading"><strong>YZ</strong><span>0° +Z · 90° +Y</span></div>
+                    <svg id="beam-pattern-plot-yz" viewBox="0 0 520 520" role="img" aria-label="YZ 수신 빔 패턴 polar plot" aria-describedby="beam-pattern-status beam-pattern-model-note beam-pattern-caption-yz"></svg>
+                    <figcaption id="beam-pattern-caption-yz">계산 중…</figcaption>
+                  </figure>
+                  <figure class="beam-pattern-figure" data-cut="xy">
+                    <div class="beam-pattern-figure-heading"><strong>XY</strong><span>0° +X · 90° +Y</span></div>
+                    <svg id="beam-pattern-plot-xy" viewBox="0 0 520 520" role="img" aria-label="XY 수신 빔 패턴 polar plot" aria-describedby="beam-pattern-status beam-pattern-model-note beam-pattern-caption-xy"></svg>
+                    <figcaption id="beam-pattern-caption-xy">계산 중…</figcaption>
+                  </figure>
+                </div>
+
+                <figure class="beam-pattern-surface-figure" id="beam-pattern-surface-view" hidden>
+                  <div class="beam-pattern-figure-heading"><strong>3D 구면 응답</strong><span>drag하여 회전 · +Z FRONT</span></div>
+                  <canvas id="beam-pattern-surface" tabindex="0" role="img" aria-label="3D 수신 빔 패턴 표면" aria-describedby="beam-pattern-status beam-pattern-model-note beam-pattern-surface-caption"></canvas>
+                  <figcaption id="beam-pattern-surface-caption">3D 표면을 준비하고 있습니다.</figcaption>
+                </figure>
+
+                <div class="beam-pattern-diagnostics" id="beam-pattern-peaks" aria-label="평면별 sampled peak 진단">
+                  <p data-cut="xz"><strong>XZ</strong><span>계산 중…</span></p>
+                  <p data-cut="yz"><strong>YZ</strong><span>계산 중…</span></p>
+                  <p data-cut="xy"><strong>XY</strong><span>계산 중…</span></p>
+                </div>
+              </div>
             </div>
           </details>
 
diff --git a/apps/array-builder/main.js b/apps/array-builder/main.js
index 1f6c548..631a66b 100644
--- a/apps/array-builder/main.js
+++ b/apps/array-builder/main.js
@@ -1,8 +1,12 @@
 import { downloadJson, readJsonFile } from "/packages/contracts/io.js";
 import { validateArrayDefinition } from "/packages/contracts/validation.js";
-import { computeReceiveBeamPattern } from "/packages/acoustics-core/beam-pattern.js";
+import {
+  computeReceiveBeamPattern,
+  computeReceiveBeamPatternSphere,
+} from "/packages/acoustics-core/beam-pattern.js";
 import { createSplitPane } from "/packages/ui/split-pane.js";
 import { createArrayCanvas } from "./canvas-view.js";
+import { createReceiveBeamPatternSurfaceView } from "./beam-pattern-surface-view.js";
 import { createReceiveBeamPatternView } from "./beam-pattern-view.js";
 import {
   addMicrophone,
@@ -36,14 +40,22 @@ const requiredIds = [
   "aperture-shape", "preset-type", "preset-count", "preset-columns",
   "preset-rows", "preset-seed", "preset-minimum-spacing",
   "generate-preset-button", "array-canvas", "select-tool-button",
-  "add-tool-button", "fit-view-button", "zoom-in-button", "zoom-out-button",
+  "add-tool-button", "array-view-2d-button", "array-view-3d-button",
+  "canvas-front-badge", "fit-view-button", "zoom-in-button", "zoom-out-button",
   "snap-enabled", "snap-step", "microphone-list", "microphone-id",
   "microphone-x", "microphone-y", "microphone-z", "add-microphone-button",
   "remove-microphone-button", "validation-title", "validation-message",
-  "beam-pattern-panel", "beam-pattern-frequency",
-  "beam-pattern-speed-of-sound", "beam-pattern-cut",
-  "beam-pattern-steering-angle", "beam-pattern-samples",
-  "beam-pattern-floor", "beam-pattern-plot", "beam-pattern-status",
+  "beam-pattern-panel", "beam-pattern-frequency", "beam-pattern-frequency-value",
+  "beam-pattern-speed-of-sound", "beam-pattern-steering-angle",
+  "beam-pattern-steering-azimuth", "beam-pattern-steering-elevation",
+  "beam-pattern-samples", "beam-pattern-surface-resolution",
+  "beam-pattern-floor", "beam-pattern-view-cuts-button",
+  "beam-pattern-view-3d-button", "beam-pattern-cuts-view",
+  "beam-pattern-surface-view", "beam-pattern-surface",
+  "beam-pattern-plot-xz", "beam-pattern-plot-yz", "beam-pattern-plot-xy",
+  "beam-pattern-caption-xz", "beam-pattern-caption-yz",
+  "beam-pattern-caption-xy", "beam-pattern-surface-caption",
+  "beam-pattern-status",
   "beam-pattern-summary", "beam-pattern-wavelength",
   "beam-pattern-resolution", "beam-pattern-steering-response",
   "beam-pattern-hpbw", "beam-pattern-peaks",
@@ -62,7 +74,14 @@ const optionalIds = [
 ];
 for (const id of optionalIds) elements[id] = maybeById(id);
 elements.validationCard = elements["validation-title"].closest(".validation-card");
-const beamPatternView = createReceiveBeamPatternView(elements["beam-pattern-plot"]);
+const BEAM_PATTERN_CUTS = Object.freeze(["xz", "yz", "xy"]);
+const beamPatternViews = Object.fromEntries(BEAM_PATTERN_CUTS.map((cut) => [
+  cut,
+  createReceiveBeamPatternView(elements["beam-pattern-plot-" + cut]),
+]));
+const beamPatternSurfaceView = createReceiveBeamPatternSurfaceView(
+  elements["beam-pattern-surface"],
+);
 
 const splitPane = createSplitPane({
   container: elements["array-builder-layout"],
@@ -92,6 +111,8 @@ const state = {
   dragSnapshot: null,
   importRevision: 0,
   baselineSignature: "",
+  arrayViewMode: "2d",
+  beamPatternViewMode: "cuts",
   beamPatternRenderFrame: 0,
   beamPatternDirty: true,
   beamPatternPreviewPending: false,
@@ -337,6 +358,7 @@ function dismissCanvasInstructions() {
 }
 
 function setTool(tool, options = {}) {
+  if (state.arrayViewMode === "3d" && tool === "add") return state.tool;
   state.tool = tool === "add" ? "add" : "select";
   elements["select-tool-button"].classList.toggle("is-active", state.tool === "select");
   elements["add-tool-button"].classList.toggle("is-active", state.tool === "add");
@@ -351,12 +373,66 @@ function setTool(tool, options = {}) {
   if (options.focus) canvasView.focus();
 }
 
+function setArrayViewMode(mode, options = {}) {
+  const resolved = mode === "3d" ? "3d" : "2d";
+  state.arrayViewMode = resolved;
+  if (resolved === "3d") state.tool = "select";
+  elements["array-view-2d-button"].classList.toggle("is-active", resolved === "2d");
+  elements["array-view-3d-button"].classList.toggle("is-active", resolved === "3d");
+  elements["array-view-2d-button"].setAttribute("aria-pressed", String(resolved === "2d"));
+  elements["array-view-3d-button"].setAttribute("aria-pressed", String(resolved === "3d"));
+  elements["add-tool-button"].disabled = resolved === "3d";
+  elements["select-tool-button"].disabled = resolved === "3d";
+  const instruction = elements["canvas-instructions"];
+  if (instruction) {
+    const title = instruction.querySelector("strong");
+    const detail = instruction.querySelector("span");
+    if (title) {
+      title.textContent = resolved === "3d"
+        ? "드래그하여 배열을 회전하고 채널을 클릭해 선택하세요."
+        : "마이크를 클릭하거나 드래그해 위치를 편집하세요.";
+    }
+    if (detail) {
+      detail.textContent = resolved === "3d"
+        ? "3D는 검사 전용입니다. 방향키로 회전하고 R로 초기화하며, 좌표 수정은 2D 또는 x/y/z 입력에서 합니다."
+        : "추가 도구에서는 빈 공간을 클릭해 새 채널을 만듭니다.";
+    }
+    instruction.classList.remove("is-hidden");
+  }
+  elements["canvas-front-badge"].textContent = resolved === "3d"
+    ? "+Z FRONT · 초록 축"
+    : "+Z FRONT · 화면 바깥쪽";
+  elements["array-canvas"].setAttribute(
+    "aria-label",
+    resolved === "3d"
+      ? "마이크 어레이 3D 검사 canvas, 드래그하여 회전"
+      : "마이크 어레이 평면 편집 canvas",
+  );
+  elements["array-canvas"].setAttribute(
+    "aria-keyshortcuts",
+    resolved === "3d"
+      ? "ArrowLeft ArrowRight ArrowUp ArrowDown F R Escape"
+      : "V A F Escape Delete ArrowLeft ArrowRight ArrowUp ArrowDown",
+  );
+  setTool(state.tool);
+  canvasView.render(canvasState());
+  if (options.focus) canvasView.focus();
+  if (options.announce !== false) {
+    announceSelection(
+      resolved === "3d"
+        ? "3D 검사 · +Z가 FRONT입니다."
+        : "2D 편집 · +Z FRONT는 화면 바깥 방향입니다.",
+    );
+  }
+}
+
 function canvasState() {
   return {
     arrayDefinition: state.arrayDefinition,
     apertureShape: state.apertureShape,
     selectedMicrophoneId: state.selectedMicrophoneId,
     tool: state.tool,
+    viewMode: state.arrayViewMode,
     snapStepM: state.snapEnabled ? state.snapStepM : 0,
   };
 }
@@ -496,13 +572,24 @@ const canvasView = createArrayCanvas(elements["array-canvas"], {
 });
 
 const beamPatternInputIds = [
-  "beam-pattern-frequency",
   "beam-pattern-speed-of-sound",
-  "beam-pattern-cut",
   "beam-pattern-steering-angle",
+  "beam-pattern-steering-azimuth",
+  "beam-pattern-steering-elevation",
   "beam-pattern-samples",
+  "beam-pattern-surface-resolution",
   "beam-pattern-floor",
 ];
+const BEAM_FREQUENCY_LOG_STEPS_PER_DECADE = 1000;
+const BEAM_PATTERN_LIVE_EVALUATION_BUDGET = 2_400_000;
+const BEAM_PATTERN_FULL_EVALUATION_BUDGET = 16_000_000;
+
+function beamPatternEvaluationBudget(preview, simultaneousViews = 1) {
+  const total = preview
+    ? BEAM_PATTERN_LIVE_EVALUATION_BUDGET
+    : BEAM_PATTERN_FULL_EVALUATION_BUDGET;
+  return Math.floor(total / simultaneousViews);
+}
 
 function beamPatternNumber(id, label, options) {
   const element = elements[id];
@@ -516,39 +603,35 @@ function beamPatternNumber(id, label, options) {
   }
 }
 
-function readBeamPatternOptions(preview) {
-  for (const id of beamPatternInputIds) elements[id].removeAttribute("aria-invalid");
-  const frequencyHz = beamPatternNumber(
-    "beam-pattern-frequency",
-    "아날로그 주파수",
-    { exclusiveMinimum: 0, maximum: 1_000_000 },
+function beamPatternFrequencyHz() {
+  const slider = elements["beam-pattern-frequency"];
+  const logarithmicPosition = finiteInput(slider, "아날로그 주파수 slider", {
+    minimum: 0,
+    maximum: 6000,
+  });
+  return Number(
+    Math.pow(10, logarithmicPosition / BEAM_FREQUENCY_LOG_STEPS_PER_DECADE)
+      .toPrecision(12),
   );
+}
+
+function syncBeamPatternFrequency() {
+  const frequencyHz = beamPatternFrequencyHz();
+  const formatted = formatBeamFrequency(frequencyHz);
+  elements["beam-pattern-frequency-value"].textContent = formatted;
+  elements["beam-pattern-frequency"].setAttribute("aria-valuenow", String(frequencyHz));
+  elements["beam-pattern-frequency"].setAttribute("aria-valuetext", formatted);
+  return frequencyHz;
+}
+
+function readBeamPatternCommonOptions() {
+  for (const id of beamPatternInputIds) elements[id].removeAttribute("aria-invalid");
+  const frequencyHz = syncBeamPatternFrequency();
   const speedOfSound = beamPatternNumber(
     "beam-pattern-speed-of-sound",
     "음속",
     { minimum: 250, maximum: 400 },
   );
-  const steeringAngleDeg = beamPatternNumber(
-    "beam-pattern-steering-angle",
-    "조향각",
-    { minimum: -360, maximum: 360 },
-  );
-  const cut = elements["beam-pattern-cut"].value;
-  if (!["xy", "xz", "yz"].includes(cut)) {
-    elements["beam-pattern-cut"].setAttribute("aria-invalid", "true");
-    throw new Error("절단면은 XY, XZ 또는 YZ여야 합니다.");
-  }
-  const sampleValue = elements["beam-pattern-samples"].value;
-  const configuredSampleCount = sampleValue === "auto"
-    ? "auto"
-    : Number(sampleValue);
-  if (
-    configuredSampleCount !== "auto" &&
-    (!Number.isInteger(configuredSampleCount) || configuredSampleCount < 36)
-  ) {
-    elements["beam-pattern-samples"].setAttribute("aria-invalid", "true");
-    throw new Error("각도 샘플 설정이 올바르지 않습니다.");
-  }
   const dbFloor = Number(elements["beam-pattern-floor"].value);
   if (!Number.isFinite(dbFloor) || dbFloor >= 0) {
     elements["beam-pattern-floor"].setAttribute("aria-invalid", "true");
@@ -558,18 +641,73 @@ function readBeamPatternOptions(preview) {
     array: state.arrayDefinition,
     frequencyHz,
     speedOfSound,
-    cut,
-    steeringAngleDeg,
-    sampleCount: preview
-      ? Math.min(
-        configuredSampleCount === "auto" ? 720 : configuredSampleCount,
-        720,
-      )
-      : configuredSampleCount,
     dbFloor,
   };
 }
 
+function readBeamPatternCutOptions(preview) {
+  const common = readBeamPatternCommonOptions();
+  const steeringAngleDeg = beamPatternNumber(
+    "beam-pattern-steering-angle",
+    "단면별 조향각",
+    { minimum: -360, maximum: 360 },
+  );
+  const sampleValue = elements["beam-pattern-samples"].value;
+  const configuredSampleCount = sampleValue === "auto" ? "auto" : Number(sampleValue);
+  if (
+    configuredSampleCount !== "auto" &&
+    (!Number.isInteger(configuredSampleCount) || configuredSampleCount < 36)
+  ) {
+    elements["beam-pattern-samples"].setAttribute("aria-invalid", "true");
+    throw new Error("각도 샘플 설정이 올바르지 않습니다.");
+  }
+  return {
+    ...common,
+    steeringAngleDeg,
+    maximumEvaluations: beamPatternEvaluationBudget(
+      preview,
+      BEAM_PATTERN_CUTS.length,
+    ),
+    sampleCount: preview
+      ? Math.min(configuredSampleCount === "auto" ? 720 : configuredSampleCount, 720)
+      : configuredSampleCount,
+  };
+}
+
+function readBeamPatternSurfaceOptions(preview) {
+  const common = readBeamPatternCommonOptions();
+  const steeringAzimuthDeg = beamPatternNumber(
+    "beam-pattern-steering-azimuth",
+    "3D 조향 방위각",
+    { minimum: -360, maximum: 360 },
+  );
+  const steeringElevationDeg = beamPatternNumber(
+    "beam-pattern-steering-elevation",
+    "3D 조향 고도각",
+    { minimum: -90, maximum: 90 },
+  );
+  const configuredStepDeg = Number(elements["beam-pattern-surface-resolution"].value);
+  if (
+    !Number.isFinite(configuredStepDeg) ||
+    configuredStepDeg < 1 ||
+    configuredStepDeg > 15 ||
+    360 % configuredStepDeg !== 0 ||
+    180 % configuredStepDeg !== 0
+  ) {
+    elements["beam-pattern-surface-resolution"].setAttribute("aria-invalid", "true");
+    throw new Error("3D 구면 표본 간격이 올바르지 않습니다.");
+  }
+  const stepDeg = preview ? Math.max(6, configuredStepDeg) : configuredStepDeg;
+  return {
+    ...common,
+    steeringAzimuthDeg,
+    steeringElevationDeg,
+    maximumEvaluations: beamPatternEvaluationBudget(preview),
+    azimuthSampleCount: Math.round(360 / stepDeg),
+    elevationSampleCount: Math.round(180 / stepDeg) + 1,
+  };
+}
+
 function formatBeamFrequency(frequencyHz) {
   if (frequencyHz >= 1_000_000) return (frequencyHz / 1_000_000).toFixed(3) + " MHz";
   if (frequencyHz >= 1_000) return (frequencyHz / 1_000).toFixed(3) + " kHz";
@@ -624,80 +762,198 @@ function setBeamPatternStatus(message, severity = "success") {
   elements["beam-pattern-status"].dataset.severity = severity;
 }
 
+function renderBeamPatternCuts(preview, startedAt) {
+  const options = readBeamPatternCutOptions(preview);
+  const patterns = BEAM_PATTERN_CUTS.map((cut) =>
+    computeReceiveBeamPattern({ ...options, cut }));
+  for (const pattern of patterns) {
+    const cut = pattern.cut;
+    const plot = elements["beam-pattern-plot-" + cut];
+    beamPatternViews[cut].render(pattern);
+    plot.dataset.sampleCount = String(pattern.sampleCount);
+    plot.dataset.cut = cut;
+    plot.dataset.frequencyHz = String(pattern.frequencyHz);
+    elements["beam-pattern-caption-" + cut].textContent =
+      pattern.sampleCount.toLocaleString("ko-KR") + " samples · " +
+      (preview
+        ? "live preview · 놓으면 HPBW 재계산"
+        : "HPBW " + formatBeamHpbw(pattern.metrics.halfPowerBeamwidth));
+    const diagnostic = elements["beam-pattern-peaks"].querySelector(
+      '[data-cut="' + cut + '"] span',
+    );
+    if (diagnostic) {
+      diagnostic.textContent = preview
+        ? "live raw samples · 놓으면 peak 재계산"
+        : describeBeamPatternPeaks(pattern);
+    }
+  }
+
+  const reference = patterns[0];
+  elements["beam-pattern-summary"].textContent =
+    formatBeamFrequency(reference.frequencyHz) + " · XZ/YZ/XY 동시 · " +
+    reference.steeringAngleDeg.toFixed(1) + "° 독립 조향";
+  elements["beam-pattern-wavelength"].textContent =
+    formatBeamWavelength(reference.wavelengthM);
+  elements["beam-pattern-resolution"].textContent = patterns
+    .map((pattern) =>
+      pattern.cut.toUpperCase() + " " +
+      pattern.sampleCount.toLocaleString("ko-KR") + " / " +
+      pattern.angularResolutionDeg.toFixed(3) + "°")
+    .join(" · ");
+  elements["beam-pattern-steering-response"].textContent = patterns
+    .map((pattern) =>
+      pattern.cut.toUpperCase() + " " +
+      formatBeamDecibels(pattern.metrics.steeringDb))
+    .join(" · ");
+  elements["beam-pattern-hpbw"].textContent = preview
+    ? "slider/drag 종료 후 계산"
+    : patterns
+      .map((pattern) =>
+        pattern.cut.toUpperCase() + " " +
+        formatBeamHpbw(pattern.metrics.halfPowerBeamwidth))
+      .join(" · ");
+
+  if (!preview) {
+    const elapsedMs = performance.now() - startedAt;
+    const unresolved = patterns.filter(
+      (pattern) => !pattern.angularSampling.metricResolutionSatisfied,
+    );
+    const missingCrossing = patterns.filter(
+      (pattern) =>
+        pattern.metrics.halfPowerBeamwidth.status ===
+        "no-sampled-half-power-crossing",
+    );
+    const evaluationCount = patterns.reduce(
+      (sum, pattern) => sum + pattern.evaluationCount,
+      0,
+    );
+    document.documentElement.dataset.beamPatternComputeMs = elapsedMs.toFixed(3);
+    if (unresolved.length) {
+      setBeamPatternStatus(
+        unresolved.map((pattern) => pattern.cut.toUpperCase()).join("/") +
+        " raw polar 표본은 표시했지만 π/8 인접 위상 기준을 넘겨 HPBW·peak 해석을 보류합니다. · " +
+        elapsedMs.toFixed(1) + " ms",
+        "warning",
+      );
+    } else if (missingCrossing.length) {
+      setBeamPatternStatus(
+        missingCrossing.map((pattern) => pattern.cut.toUpperCase()).join("/") +
+        "에서 sampled half-power crossing이 없어 전 방향 HPBW라고 단정하지 않습니다. · " +
+        elapsedMs.toFixed(1) + " ms",
+        "warning",
+      );
+    } else {
+      setBeamPatternStatus(
+        "세 평면 π/8 인접 위상 기준 충족 · " +
+        evaluationCount.toLocaleString("ko-KR") +
+        " microphone-angle evaluations · " + elapsedMs.toFixed(1) + " ms",
+        "success",
+      );
+    }
+  }
+}
+
+function renderBeamPatternSurface(preview, startedAt) {
+  const options = readBeamPatternSurfaceOptions(preview);
+  const surface = computeReceiveBeamPatternSphere(options);
+  beamPatternSurfaceView.render(surface);
+  elements["beam-pattern-summary"].textContent =
+    formatBeamFrequency(surface.frequencyHz) + " · 3D · az " +
+    surface.steeringAzimuthDeg.toFixed(1) + "° / el " +
+    surface.steeringElevationDeg.toFixed(1) + "°";
+  elements["beam-pattern-wavelength"].textContent =
+    formatBeamWavelength(surface.wavelengthM);
+  elements["beam-pattern-resolution"].textContent =
+    surface.angularSampling.azimuthStepDeg.toFixed(3) + "° az · " +
+    surface.angularSampling.elevationStepDeg.toFixed(3) + "° el · " +
+    surface.sampleCount.toLocaleString("ko-KR") + " grid samples";
+  elements["beam-pattern-steering-response"].textContent =
+    "0.000 dB · analytic u=u₀";
+  elements["beam-pattern-hpbw"].textContent =
+    "3D 표면 · 평면 HPBW 미적용";
+  elements["beam-pattern-surface-caption"].textContent =
+    surface.azimuthSampleCount + "×" + surface.elevationSampleCount +
+    " raw grid samples · dB-floor radial mapping · response interpolation 없음 · " +
+    (preview ? "live preview" : "drag/방향키로 회전");
+  if (!preview) {
+    const elapsedMs = performance.now() - startedAt;
+    document.documentElement.dataset.beamPatternComputeMs = elapsedMs.toFixed(3);
+    if (!surface.angularSampling.resolutionCriterionSatisfied) {
+      setBeamPatternStatus(
+        "Raw 3D 표면은 표시했습니다. 구면 cell 대각 위상 변화 " +
+        surface.angularSampling.maximumCellDiagonalPhaseStepRadBound.toFixed(3) +
+        " rad가 π/8 기준을 넘으므로 미세 lobe 해석은 미확정입니다. · " +
+        elapsedMs.toFixed(1) + " ms",
+        "warning",
+      );
+    } else {
+      setBeamPatternStatus(
+        "3D 구면 π/8 cell 대각 위상 기준 충족 · " +
+        surface.evaluationCount.toLocaleString("ko-KR") +
+        " microphone-direction evaluations · " + elapsedMs.toFixed(1) + " ms",
+        "success",
+      );
+    }
+  }
+}
+
 function renderBeamPattern(preview = false) {
   const startedAt = performance.now();
   try {
-    const options = readBeamPatternOptions(preview);
-    const pattern = computeReceiveBeamPattern(options);
-    beamPatternView.render(pattern);
+    if (state.beamPatternViewMode === "surface") {
+      renderBeamPatternSurface(preview, startedAt);
+    } else {
+      renderBeamPatternCuts(preview, startedAt);
+    }
     state.beamPatternDirty = false;
     document.documentElement.dataset.beamPatternReady = "true";
     document.documentElement.dataset.beamPatternPreview = String(preview);
-    elements["beam-pattern-plot"].dataset.sampleCount = String(pattern.sampleCount);
-    elements["beam-pattern-plot"].dataset.cut = pattern.cut;
-    elements["beam-pattern-plot"].dataset.frequencyHz = String(pattern.frequencyHz);
-    elements["beam-pattern-summary"].textContent =
-      formatBeamFrequency(pattern.frequencyHz) + " · " +
-      pattern.cut.toUpperCase() + " · " +
-      pattern.steeringAngleDeg.toFixed(1) + "° 조향";
-    elements["beam-pattern-wavelength"].textContent =
-      formatBeamWavelength(pattern.wavelengthM);
-    elements["beam-pattern-resolution"].textContent =
-      pattern.sampleCount.toLocaleString("ko-KR") + " · " +
-      pattern.angularResolutionDeg.toFixed(4) + "°";
-    elements["beam-pattern-steering-response"].textContent =
-      formatBeamDecibels(pattern.metrics.steeringDb);
-    elements["beam-pattern-hpbw"].textContent = preview
-      ? "드래그 종료 후 계산"
-      : formatBeamHpbw(pattern.metrics.halfPowerBeamwidth);
-
-    if (!preview) {
-      elements["beam-pattern-peaks"].textContent =
-        describeBeamPatternPeaks(pattern);
-      const elapsedMs = performance.now() - startedAt;
-      document.documentElement.dataset.beamPatternComputeMs =
-        elapsedMs.toFixed(3);
-      if (!pattern.angularSampling.metricResolutionSatisfied) {
-        setBeamPatternStatus(
-          "Raw polar 표본은 표시했습니다. 최대 인접 위상 변화 " +
-          pattern.angularSampling.maximumAdjacentPhaseStepRadBound.toFixed(3) +
-          " rad가 π/8 기준을 넘으므로 HPBW와 peak 해석은 보류합니다." +
-          (pattern.angularSampling.autoCapped ? " 자동 샘플은 안전 상한에서 제한됐습니다." : "") +
-          " · " + elapsedMs.toFixed(1) + " ms",
-          "warning",
-        );
-      } else if (
-        pattern.metrics.halfPowerBeamwidth.status ===
-        "no-sampled-half-power-crossing"
-      ) {
-        setBeamPatternStatus(
-          "π/8 인접 위상 간격 기준은 충족했지만 sampled half-power crossing이 없습니다. " +
-          "전 방향 HPBW라고 단정하지 않습니다. · " + elapsedMs.toFixed(1) + " ms",
-          "warning",
-        );
-      } else {
-        setBeamPatternStatus(
-          "π/8 인접 위상 간격 기준 충족 · " +
-          pattern.sampleCount.toLocaleString("ko-KR") + " angles · " +
-          pattern.evaluationCount.toLocaleString("ko-KR") +
-          " phasor evaluations · " + elapsedMs.toFixed(1) + " ms",
-          "success",
-        );
-      }
-    }
+    document.documentElement.dataset.beamPatternView = state.beamPatternViewMode;
   } catch (error) {
     state.beamPatternDirty = false;
     document.documentElement.dataset.beamPatternReady = "error";
-    document.documentElement.dataset.beamPatternPreview = "false";
+    document.documentElement.dataset.beamPatternPreview = String(preview);
     const message = error instanceof Error ? error.message : String(error);
-    beamPatternView.renderError(message);
+    for (const view of Object.values(beamPatternViews)) view.renderError(message);
+    beamPatternSurfaceView.renderError(message);
     setBeamPatternStatus(message, "error");
     elements["beam-pattern-hpbw"].textContent = "—";
-    elements["beam-pattern-peaks"].textContent =
-      "빔 패턴 설정을 수정하면 다시 계산합니다.";
+    for (const diagnostic of elements["beam-pattern-peaks"].querySelectorAll("span")) {
+      diagnostic.textContent = "설정을 수정하면 다시 계산합니다.";
+    }
   }
 }
 
+function setBeamPatternViewMode(mode, options = {}) {
+  const resolved = mode === "surface" ? "surface" : "cuts";
+  state.beamPatternViewMode = resolved;
+  elements["beam-pattern-view-cuts-button"].classList.toggle(
+    "is-active",
+    resolved === "cuts",
+  );
+  elements["beam-pattern-view-3d-button"].classList.toggle(
+    "is-active",
+    resolved === "surface",
+  );
+  elements["beam-pattern-view-cuts-button"].setAttribute(
+    "aria-pressed",
+    String(resolved === "cuts"),
+  );
+  elements["beam-pattern-view-3d-button"].setAttribute(
+    "aria-pressed",
+    String(resolved === "surface"),
+  );
+  for (const field of document.querySelectorAll("[data-beam-mode]")) {
+    field.hidden = field.dataset.beamMode !== resolved;
+  }
+  elements["beam-pattern-cuts-view"].hidden = resolved !== "cuts";
+  elements["beam-pattern-peaks"].hidden = resolved !== "cuts";
+  elements["beam-pattern-surface-view"].hidden = resolved !== "surface";
+  document.documentElement.dataset.beamPatternView = resolved;
+  state.beamPatternDirty = true;
+  if (options.render !== false) scheduleBeamPatternRender();
+}
+
 function scheduleBeamPatternRender(options = {}) {
   const preview = options.preview === true;
   state.beamPatternDirty = true;
@@ -1093,6 +1349,10 @@ elements["select-tool-button"].addEventListener("click", () =>
   setTool("select", { focus: true, userInitiated: true }));
 elements["add-tool-button"].addEventListener("click", () =>
   setTool("add", { focus: true, userInitiated: true }));
+elements["array-view-2d-button"].addEventListener("click", () =>
+  setArrayViewMode("2d", { focus: true }));
+elements["array-view-3d-button"].addEventListener("click", () =>
+  setArrayViewMode("3d", { focus: true }));
 elements["fit-view-button"].addEventListener("click", () => canvasView.fit());
 elements["zoom-in-button"].addEventListener("click", () => canvasView.zoomBy(1.25));
 elements["zoom-out-button"].addEventListener("click", () => canvasView.zoomBy(0.8));
@@ -1102,10 +1362,25 @@ elements["snap-enabled"].addEventListener("change", () => {
   announce(state.snapEnabled ? "Snap 켜짐" : "Snap 꺼짐");
 });
 
+elements["beam-pattern-frequency"].addEventListener("input", () => {
+  syncBeamPatternFrequency();
+  scheduleBeamPatternRender({ preview: true });
+});
+elements["beam-pattern-frequency"].addEventListener("change", () =>
+  scheduleBeamPatternRender());
 for (const id of beamPatternInputIds) {
-  const eventName = elements[id] instanceof HTMLInputElement ? "input" : "change";
-  elements[id].addEventListener(eventName, () => scheduleBeamPatternRender());
+  if (elements[id] instanceof HTMLInputElement) {
+    elements[id].addEventListener("input", () =>
+      scheduleBeamPatternRender({ preview: true }));
+    elements[id].addEventListener("change", () => scheduleBeamPatternRender());
+  } else {
+    elements[id].addEventListener("change", () => scheduleBeamPatternRender());
+  }
 }
+elements["beam-pattern-view-cuts-button"].addEventListener("click", () =>
+  setBeamPatternViewMode("cuts"));
+elements["beam-pattern-view-3d-button"].addEventListener("click", () =>
+  setBeamPatternViewMode("surface"));
 elements["beam-pattern-panel"].addEventListener("toggle", () => {
   if (elements["beam-pattern-panel"].open && state.beamPatternDirty) {
     scheduleBeamPatternRender();
@@ -1314,13 +1589,17 @@ window.addEventListener("unload", () => {
   if (state.beamPatternRenderFrame) {
     cancelAnimationFrame(state.beamPatternRenderFrame);
   }
-  beamPatternView.destroy();
+  for (const view of Object.values(beamPatternViews)) view.destroy();
+  beamPatternSurfaceView.destroy();
   splitPane.destroy();
   canvasView.destroy();
 });
 
 elements["snap-enabled"].checked = state.snapEnabled;
 setNumber(elements["snap-step"], state.snapStepM * 1000);
+setArrayViewMode("2d", { announce: false });
+setBeamPatternViewMode("cuts", { render: false });
+syncBeamPatternFrequency();
 renderAll("기본 4×3 배열");
 canvasView.fit();
 document.documentElement.dataset.appReady = "true";
diff --git a/apps/array-builder/styles.css b/apps/array-builder/styles.css
index e3acd06..a2fe2bb 100644
--- a/apps/array-builder/styles.css
+++ b/apps/array-builder/styles.css
@@ -633,7 +633,9 @@ details > summary::-webkit-details-marker {
 }
 
 .beam-pattern-controls,
-.beam-pattern-figure {
+.beam-pattern-visuals,
+.beam-pattern-figure,
+.beam-pattern-surface-figure {
   min-width: 0;
 }
 
@@ -658,12 +660,59 @@ details > summary::-webkit-details-marker {
   font-size: 0.55rem;
 }
 
+.beam-pattern-view-switch {
+  display: inline-flex;
+  gap: 5px;
+  margin-bottom: 11px;
+  padding: 3px;
+  border: 1px solid var(--line);
+  border-radius: 10px;
+  background: #07110f;
+}
+
+.beam-pattern-view-switch .tool-button {
+  min-width: 82px;
+}
+
 .beam-pattern-fields {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
   gap: 9px;
 }
 
+.beam-frequency-field {
+  grid-column: 1 / -1;
+}
+
+.beam-frequency-field > small,
+.beam-pattern-fields .field > small {
+  margin-top: 5px;
+  color: var(--muted);
+  font-size: 0.56rem;
+  line-height: 1.4;
+}
+
+.beam-frequency-control {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) minmax(92px, auto);
+  align-items: center;
+  gap: 10px;
+}
+
+#beam-pattern-frequency {
+  min-width: 0;
+  padding-inline: 0;
+  accent-color: var(--mint);
+  cursor: ew-resize;
+}
+
+#beam-pattern-frequency-value {
+  color: var(--mint);
+  font: 760 0.72rem ui-monospace, SFMono-Regular, Consolas, monospace;
+  text-align: right;
+  white-space: nowrap;
+}
+
 .beam-pattern-metrics {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
@@ -728,36 +777,139 @@ details > summary::-webkit-details-marker {
   overflow-wrap: anywhere;
 }
 
-.beam-pattern-figure {
+.beam-pattern-visuals {
+  display: grid;
+  min-width: 0;
+  align-content: start;
+  gap: 11px;
+}
+
+.beam-pattern-cut-grid {
+  display: grid;
+  min-width: 0;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 10px;
+}
+
+.beam-pattern-figure,
+.beam-pattern-surface-figure {
   display: grid;
   align-content: start;
-  justify-items: center;
-  gap: 9px;
+  gap: 7px;
   margin: 0;
 }
 
-#beam-pattern-plot {
+.beam-pattern-figure-heading {
+  display: flex;
+  min-width: 0;
+  align-items: baseline;
+  justify-content: space-between;
+  gap: 7px;
+}
+
+.beam-pattern-figure-heading strong {
+  color: #edf9f4;
+  font-size: 0.7rem;
+}
+
+.beam-pattern-figure-heading span {
+  min-width: 0;
+  color: var(--muted);
+  font: 620 0.53rem ui-monospace, SFMono-Regular, Consolas, monospace;
+  overflow-wrap: anywhere;
+  text-align: right;
+}
+
+#beam-pattern-plot-xz,
+#beam-pattern-plot-yz,
+#beam-pattern-plot-xy {
   display: block;
-  width: min(100%, 580px);
+  width: 100%;
   height: auto;
   aspect-ratio: 1;
   overflow: visible;
-  border: 1px solid var(--line);
-  border-radius: 14px;
+  border: 1px solid rgb(145 170 162 / 22%);
+  border-radius: 11px;
   color: var(--mint);
   background: #07110f;
 }
 
 .beam-pattern-figure figcaption {
-  width: min(100%, 580px);
-  min-height: 2.8em;
+  min-height: 3.8em;
   margin: 0;
   color: var(--muted);
-  font-size: 0.61rem;
+  font-size: 0.56rem;
   line-height: 1.45;
   overflow-wrap: anywhere;
 }
 
+.beam-pattern-surface-figure {
+  justify-items: stretch;
+}
+
+#beam-pattern-surface {
+  display: block;
+  width: 100%;
+  height: auto;
+  aspect-ratio: 16 / 10;
+  border: 1px solid rgb(145 170 162 / 24%);
+  border-radius: 12px;
+  background: #07110f;
+  cursor: grab;
+  touch-action: none;
+}
+
+#beam-pattern-surface[data-orbiting="true"] {
+  cursor: grabbing;
+}
+
+#beam-pattern-surface:focus-visible {
+  outline: 2px solid var(--mint);
+  outline-offset: -3px;
+}
+
+.beam-pattern-surface-figure figcaption {
+  color: var(--muted);
+  font-size: 0.58rem;
+  line-height: 1.45;
+}
+
+.beam-pattern-diagnostics {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 7px;
+}
+
+.beam-pattern-diagnostics p {
+  min-width: 0;
+  margin: 0;
+  padding: 8px 9px;
+  border: 1px solid var(--line);
+  border-radius: 8px;
+  color: var(--muted);
+  background: rgb(255 255 255 / 1.5%);
+  font-size: 0.55rem;
+  line-height: 1.45;
+  overflow-wrap: anywhere;
+}
+
+.beam-pattern-diagnostics strong,
+.beam-pattern-diagnostics span {
+  display: block;
+}
+
+.beam-pattern-diagnostics strong {
+  margin-bottom: 3px;
+  color: #cfe2db;
+}
+
+[data-beam-mode][hidden],
+#beam-pattern-cuts-view[hidden],
+#beam-pattern-surface-view[hidden],
+#beam-pattern-peaks[hidden] {
+  display: none !important;
+}
+
 .beam-pattern-ring,
 .beam-pattern-axis {
   stroke: rgb(145 170 162 / 28%);
@@ -976,6 +1128,15 @@ body[data-array-tool="add"] #array-canvas,
   cursor: crosshair;
 }
 
+#array-canvas[data-view-mode="3d"] {
+  cursor: grab;
+  touch-action: none;
+}
+
+#array-canvas[data-view-mode="3d"][data-orbiting="true"] {
+  cursor: grabbing;
+}
+
 .canvas-instructions {
   position: absolute;
   top: 24px;
@@ -1002,6 +1163,24 @@ body[data-array-tool="add"] #array-canvas,
   display: none;
 }
 
+.canvas-front-badge {
+  position: absolute;
+  left: 12px;
+  bottom: 12px;
+  max-width: calc(100% - 190px);
+  padding: 7px 10px;
+  border: 1px solid rgb(88 199 232 / 30%);
+  border-radius: 999px;
+  color: var(--cyan);
+  background: rgb(8 17 15 / 84%);
+  backdrop-filter: blur(10px);
+  font: 720 0.62rem ui-monospace, SFMono-Regular, Consolas, monospace;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  pointer-events: none;
+}
+
 .selection-status {
   position: absolute;
   right: 12px;
@@ -1093,6 +1272,17 @@ body[data-array-tool="add"] #array-canvas,
   }
 }
 
+@container beam-pattern (max-width: 620px) {
+  .beam-pattern-cut-grid,
+  .beam-pattern-diagnostics {
+    grid-template-columns: minmax(0, 1fr);
+  }
+
+  .beam-pattern-figure figcaption {
+    min-height: 0;
+  }
+}
+
 @container beam-pattern (max-width: 460px) {
   .beam-pattern-heading {
     align-items: flex-start;
@@ -1106,6 +1296,19 @@ body[data-array-tool="add"] #array-canvas,
   .beam-pattern-metrics {
     grid-template-columns: minmax(0, 1fr);
   }
+
+  .beam-frequency-field {
+    grid-column: auto;
+  }
+
+  .beam-frequency-control {
+    grid-template-columns: minmax(0, 1fr);
+    gap: 5px;
+  }
+
+  #beam-pattern-frequency-value {
+    text-align: left;
+  }
 }
 
 @media (max-width: 1280px) {
diff --git a/tests/integration/array-builder-ui.test.js b/tests/integration/array-builder-ui.test.js
index 9301f50..39ea2cc 100644
--- a/tests/integration/array-builder-ui.test.js
+++ b/tests/integration/array-builder-ui.test.js
@@ -32,6 +32,10 @@ function dispatchValue(windowObject, element, value, eventName = "change") {
   element.dispatchEvent(new windowObject.Event(eventName, { bubbles: true }));
 }
 
+function logarithmicFrequencyPosition(frequencyHz) {
+  return Math.round(Math.log10(frequencyHz) * 1000);
+}
+
 function dispatchFiles(windowObject, input, files) {
   const transfer = new windowObject.DataTransfer();
   for (const file of files) transfer.items.add(file);
@@ -102,20 +106,46 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
       () => documentObject.documentElement.dataset.beamPatternReady === "true",
       "기본 수신 빔 패턴 렌더",
     );
-    const beamPlot = documentObject.querySelector("#beam-pattern-plot");
-    const initialBeamPath = beamPlot.querySelector(".beam-pattern-response")
-      ?.getAttribute("d");
-    assert(initialBeamPath?.startsWith("M"), "polar response path is rendered");
-    assertEqual(
-      beamPlot.querySelectorAll(".beam-pattern-ring").length,
-      5,
-      "polar plot has four inner dB rings and the 0 dB ring",
-    );
-    assertEqual(beamPlot.dataset.cut, "xz", "default great-circle cut");
-    assertEqual(beamPlot.dataset.frequencyHz, "1000", "default analog frequency");
+    const beamCuts = ["xz", "yz", "xy"];
+    const beamPlots = Object.fromEntries(beamCuts.map((cut) => [
+      cut,
+      documentObject.querySelector("#beam-pattern-plot-" + cut),
+    ]));
+    const initialBeamPaths = Object.fromEntries(beamCuts.map((cut) => [
+      cut,
+      beamPlots[cut].querySelector(".beam-pattern-response")?.getAttribute("d"),
+    ]));
+    for (const cut of beamCuts) {
+      const beamPlot = beamPlots[cut];
+      assert(
+        initialBeamPaths[cut]?.startsWith("M"),
+        cut.toUpperCase() + " polar response path is rendered",
+      );
+      assertEqual(
+        beamPlot.querySelectorAll(".beam-pattern-ring").length,
+        5,
+        cut.toUpperCase() + " polar plot has four inner dB rings and the 0 dB ring",
+      );
+      assertEqual(beamPlot.dataset.cut, cut, cut.toUpperCase() + " cut provenance");
+      assertEqual(
+        beamPlot.dataset.frequencyHz,
+        "1000",
+        cut.toUpperCase() + " default analog frequency",
+      );
+      assert(
+        Number(beamPlot.dataset.sampleCount) >= 720,
+        cut.toUpperCase() + " auto angular sampling uses at least 720 directions",
+      );
+    }
     assert(
-      Number(beamPlot.dataset.sampleCount) >= 720,
-      "auto angular sampling uses at least 720 directions",
+      !documentObject.querySelector("#beam-pattern-cuts-view").hidden &&
+        documentObject.querySelector("#beam-pattern-surface-view").hidden,
+      "three polar cuts are the simultaneous default view",
+    );
+    assertEqual(
+      documentObject.querySelectorAll("#beam-pattern-cuts-view .beam-pattern-figure").length,
+      3,
+      "XZ, YZ, and XY figures are present together",
     );
     assert(
       documentObject.querySelector("#beam-pattern-model-note").textContent.includes(
@@ -125,16 +155,34 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
     );
 
     const initialSaveState = documentObject.querySelector("#save-state").textContent;
+    const frequencySlider = documentObject.querySelector("#beam-pattern-frequency");
     dispatchValue(
       windowObject,
-      documentObject.querySelector("#beam-pattern-frequency"),
-      49_125,
+      frequencySlider,
+      logarithmicFrequencyPosition(49_125),
       "input",
     );
     await waitFor(
-      () => beamPlot.dataset.frequencyHz === "49125" &&
-        Number(beamPlot.dataset.sampleCount) > 720,
-      "above-Nyquist-style analog pattern with auto angular sampling",
+      () => documentObject.documentElement.dataset.beamPatternPreview === "true" &&
+        beamCuts.every((cut) =>
+          Number(beamPlots[cut].dataset.frequencyHz) > 48_000 &&
+          beamPlots[cut].dataset.sampleCount === "720"),
+      "logarithmic slider input renders a bounded live preview in every cut",
+    );
+    const previewFrequencyHz = Number(frequencySlider.getAttribute("aria-valuenow"));
+    assert(
+      previewFrequencyHz > 48_000 && previewFrequencyHz < 50_000,
+      "log slider position maps to the intended above-Nyquist-style analog frequency",
+    );
+    assert(
+      documentObject.querySelector("#beam-pattern-frequency-value").textContent.includes("kHz"),
+      "log slider exposes its physical frequency value",
+    );
+    frequencySlider.dispatchEvent(new windowObject.Event("change", { bubbles: true }));
+    await waitFor(
+      () => documentObject.documentElement.dataset.beamPatternPreview === "false" &&
+        beamCuts.every((cut) => Number(beamPlots[cut].dataset.sampleCount) > 720),
+      "logarithmic slider change renders full auto resolution in every cut",
     );
     assert(
       documentObject.querySelector("#beam-pattern-wavelength").textContent.includes("mm"),
@@ -146,15 +194,15 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
       360,
     );
     await waitFor(
-      () => beamPlot.dataset.sampleCount === "360" &&
+      () => beamCuts.every((cut) => beamPlots[cut].dataset.sampleCount === "360") &&
         documentObject.querySelector("#beam-pattern-hpbw").textContent.includes(
           "해상도 부족",
         ),
-      "coarse angular grid exposes unresolved metrics",
+      "coarse angular grid exposes unresolved metrics for the simultaneous cuts",
     );
     dispatchValue(
       windowObject,
-      documentObject.querySelector("#beam-pattern-frequency"),
+      documentObject.querySelector("#beam-pattern-speed-of-sound"),
       "",
       "input",
     );
@@ -168,18 +216,28 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
     );
     dispatchValue(
       windowObject,
-      documentObject.querySelector("#beam-pattern-samples"),
-      "auto",
+      documentObject.querySelector("#beam-pattern-speed-of-sound"),
+      343,
+      "input",
     );
     dispatchValue(
       windowObject,
-      documentObject.querySelector("#beam-pattern-frequency"),
-      1_000,
+      frequencySlider,
+      logarithmicFrequencyPosition(1_000),
       "input",
     );
+    frequencySlider.dispatchEvent(new windowObject.Event("change", { bubbles: true }));
+    dispatchValue(
+      windowObject,
+      documentObject.querySelector("#beam-pattern-samples"),
+      "auto",
+    );
     await waitFor(
       () => documentObject.documentElement.dataset.beamPatternReady === "true" &&
-        beamPlot.dataset.frequencyHz === "1000",
+        documentObject.documentElement.dataset.beamPatternPreview === "false" &&
+        beamCuts.every((cut) =>
+          beamPlots[cut].dataset.frequencyHz === "1000" &&
+          Number(beamPlots[cut].dataset.sampleCount) >= 720),
       "beam preview recovery",
     );
     assertEqual(
@@ -187,6 +245,87 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
       initialSaveState,
       "beam preview settings are outside Array dirty state",
     );
+
+    documentObject.querySelector("#beam-pattern-view-3d-button").click();
+    const beamSurface = documentObject.querySelector("#beam-pattern-surface");
+    await waitFor(
+      () => documentObject.documentElement.dataset.beamPatternView === "surface" &&
+        documentObject.documentElement.dataset.beamPatternReady === "true" &&
+        documentObject.documentElement.dataset.beamPatternPreview === "false" &&
+        !documentObject.querySelector("#beam-pattern-surface-view").hidden &&
+        documentObject.querySelector("#beam-pattern-cuts-view").hidden &&
+        Number(beamSurface.dataset.sampleCount) > 0,
+      "3D beam surface render",
+    );
+    assert(
+      /^\d+x\d+$/.test(beamSurface.dataset.gridShape),
+      "3D beam canvas records its raw sphere grid",
+    );
+    assertEqual(
+      documentObject.querySelector("#beam-pattern-view-3d-button").getAttribute("aria-pressed"),
+      "true",
+      "3D beam view toggle is pressed",
+    );
+    assert(
+      documentObject.querySelector("#beam-pattern-surface-caption").textContent.includes(
+        "raw grid samples",
+      ),
+      "3D beam caption identifies raw sampled directions",
+    );
+    assert(
+      documentObject.querySelector("#beam-pattern-surface-caption").textContent.includes(
+        "dB-floor radial mapping",
+      ),
+      "3D beam caption discloses the display-only radial mapping",
+    );
+    await nextPaint(windowObject);
+    const surfaceBeforeOrbit = beamSurface.toDataURL();
+    const beamSurfaceRect = beamSurface.getBoundingClientRect();
+    const beamOrbitPointerId = 71;
+    beamSurface.dispatchEvent(new windowObject.PointerEvent("pointerdown", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: beamOrbitPointerId,
+      pointerType: "mouse",
+      button: 0,
+      buttons: 1,
+      clientX: beamSurfaceRect.left + beamSurfaceRect.width * 0.5,
+      clientY: beamSurfaceRect.top + beamSurfaceRect.height * 0.5,
+    }));
+    assertEqual(beamSurface.dataset.orbiting, "true", "3D beam drag begins orbiting");
+    beamSurface.dispatchEvent(new windowObject.PointerEvent("pointermove", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: beamOrbitPointerId,
+      pointerType: "mouse",
+      button: -1,
+      buttons: 1,
+      clientX: beamSurfaceRect.left + beamSurfaceRect.width * 0.7,
+      clientY: beamSurfaceRect.top + beamSurfaceRect.height * 0.36,
+    }));
+    beamSurface.dispatchEvent(new windowObject.PointerEvent("pointerup", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: beamOrbitPointerId,
+      pointerType: "mouse",
+      button: 0,
+      buttons: 0,
+    }));
+    await nextPaint(windowObject);
+    assert(!beamSurface.dataset.orbiting, "3D beam drag finishes orbiting");
+    assert(
+      beamSurface.toDataURL() !== surfaceBeforeOrbit,
+      "3D beam surface bitmap changes after orbit rotation",
+    );
+    documentObject.querySelector("#beam-pattern-view-cuts-button").click();
+    await waitFor(
+      () => documentObject.documentElement.dataset.beamPatternView === "cuts" &&
+        documentObject.documentElement.dataset.beamPatternReady === "true" &&
+        !documentObject.querySelector("#beam-pattern-cuts-view").hidden &&
+        documentObject.querySelector("#beam-pattern-surface-view").hidden,
+      "return to simultaneous polar cuts",
+    );
+
     assertEqual(microphoneCount(documentObject), 12, "default 4x3 channels");
     assertEqual(
       documentObject.querySelector("#microphone-list [data-microphone-id]").dataset.microphoneId,
@@ -203,6 +342,116 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
     );
 
     const canvas = documentObject.querySelector("#array-canvas");
+    assertEqual(canvas.dataset.viewMode, "2d", "array canvas starts in editable 2D mode");
+    assert(
+      documentObject.querySelector("#canvas-front-badge").textContent.includes(
+        "+Z FRONT · 화면 바깥쪽",
+      ),
+      "2D canvas states the +Z front direction",
+    );
+    const coordinatesBeforeArray3d = selectedCoordinates(documentObject);
+    const microphoneCountBeforeArray3d = microphoneCount(documentObject);
+    documentObject.querySelector("#array-view-3d-button").click();
+    await waitFor(
+      () => canvas.dataset.viewMode === "3d" &&
+        canvas.getAttribute("aria-label").includes("3D 검사"),
+      "array 3D inspection mode",
+    );
+    assert(
+      documentObject.querySelector("#add-tool-button").disabled &&
+        documentObject.querySelector("#select-tool-button").disabled,
+      "array canvas edit tools are disabled in 3D inspection",
+    );
+    assert(
+      documentObject.querySelector("#canvas-front-badge").textContent.includes(
+        "+Z FRONT · 초록 축",
+      ),
+      "3D canvas identifies the +Z front axis",
+    );
+    assert(
+      documentObject.querySelector("#canvas-instructions").textContent.includes("검사 전용"),
+      "3D array guidance explains that coordinate editing is disabled",
+    );
+    canvas.dispatchEvent(new windowObject.KeyboardEvent("keydown", {
+      bubbles: true,
+      cancelable: true,
+      key: "a",
+    }));
+    await nextPaint(windowObject);
+    assertEqual(canvas.dataset.tool, "select", "A shortcut cannot enable add in 3D inspection");
+    assertEqual(
+      microphoneCount(documentObject),
+      microphoneCountBeforeArray3d,
+      "3D inspection cannot add a microphone",
+    );
+    assertEqual(
+      selectedCoordinates(documentObject).join(","),
+      coordinatesBeforeArray3d.join(","),
+      "3D inspection leaves microphone coordinates unchanged",
+    );
+    const array3dBeforeOrbit = canvas.toDataURL();
+    const array3dRect = canvas.getBoundingClientRect();
+    const arrayOrbitPointerId = 72;
+    canvas.dispatchEvent(new windowObject.PointerEvent("pointerdown", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: arrayOrbitPointerId,
+      pointerType: "mouse",
+      button: 0,
+      buttons: 1,
+      clientX: array3dRect.left + array3dRect.width * 0.5,
+      clientY: array3dRect.top + array3dRect.height * 0.5,
+    }));
+    assertEqual(canvas.dataset.orbiting, "true", "array 3D drag begins orbiting");
+    canvas.dispatchEvent(new windowObject.PointerEvent("pointermove", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: arrayOrbitPointerId,
+      pointerType: "mouse",
+      button: -1,
+      buttons: 1,
+      clientX: array3dRect.left + array3dRect.width * 0.68,
+      clientY: array3dRect.top + array3dRect.height * 0.4,
+    }));
+    canvas.dispatchEvent(new windowObject.PointerEvent("pointerup", {
+      bubbles: true,
+      cancelable: true,
+      pointerId: arrayOrbitPointerId,
+      pointerType: "mouse",
+      button: 0,
+      buttons: 0,
+    }));
+    await nextPaint(windowObject);
+    assertEqual(canvas.dataset.orbiting, "false", "array 3D drag finishes orbiting");
+    assert(
+      canvas.toDataURL() !== array3dBeforeOrbit,
+      "array 3D canvas bitmap changes after orbit rotation",
+    );
+    documentObject.querySelector("#array-view-2d-button").click();
+    await waitFor(
+      () => canvas.dataset.viewMode === "2d" &&
+        canvas.getAttribute("aria-label").includes("평면 편집"),
+      "return to array 2D editing",
+    );
+    assert(
+      !documentObject.querySelector("#add-tool-button").disabled &&
+        !documentObject.querySelector("#select-tool-button").disabled,
+      "array canvas edit tools are restored in 2D",
+    );
+    assert(
+      documentObject.querySelector("#canvas-front-badge").textContent.includes(
+        "+Z FRONT · 화면 바깥쪽",
+      ),
+      "returning to 2D restores its +Z front cue",
+    );
+    documentObject.querySelector(
+      '#microphone-list [data-microphone-id="mic-001"]',
+    ).click();
+    assertEqual(
+      selectedCoordinates(documentObject).join(","),
+      coordinatesBeforeArray3d.join(","),
+      "2D edit resumes from the original microphone coordinates",
+    );
     const defaultArray = createArrayDefinition();
     const initialCanvasRect = canvas.getBoundingClientRect();
     const initialViewport = fitArrayViewport(
@@ -234,9 +483,10 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
     dispatchDragPointer("pointerup", 36, -24, 0);
     await waitFor(
       () => documentObject.documentElement.dataset.beamPatternPreview === "false" &&
-        beamPlot.querySelector(".beam-pattern-response")?.getAttribute("d") !==
-          initialBeamPath,
-      "beam pattern follows edited microphone geometry",
+        beamCuts.every((cut) =>
+          beamPlots[cut].querySelector(".beam-pattern-response")?.getAttribute("d") !==
+            initialBeamPaths[cut]),
+      "all beam-pattern cuts follow edited microphone geometry",
     );
     const draggedPosition = selectedCoordinates(documentObject);
     assert(
@@ -789,28 +1039,63 @@ test("Array Builder가 preset·직접 편집·검증·표준 JSON round trip을
         documentObject.documentElement.clientWidth + 1,
       "Array Builder has no horizontal overflow at 390px",
     );
-    const compactBeamPlotRect = documentObject.querySelector("#beam-pattern-plot")
-      .getBoundingClientRect();
     const compactBeamCardRect = documentObject.querySelector("#beam-pattern-panel")
       .getBoundingClientRect();
+    const compactBeamPlotRects = beamCuts.map((cut) =>
+      beamPlots[cut].getBoundingClientRect());
     assert(
-      compactBeamPlotRect.left >= compactBeamCardRect.left - 1 &&
-        compactBeamPlotRect.right <= compactBeamCardRect.right + 1,
-      "compact polar plot stays inside its analysis card",
+      compactBeamPlotRects.every((rect) =>
+        rect.left >= compactBeamCardRect.left - 1 &&
+        rect.right <= compactBeamCardRect.right + 1),
+      "all compact polar plots stay inside their analysis card",
     );
     assert(
-      Math.abs(compactBeamPlotRect.width - compactBeamPlotRect.height) <= 2,
-      "compact polar plot remains square",
+      compactBeamPlotRects.every((rect) => Math.abs(rect.width - rect.height) <= 2),
+      "all compact polar plots remain square",
+    );
+    assert(
+      compactBeamPlotRects.every(
+        (rect, index) => index === 0 || rect.top > compactBeamPlotRects[index - 1].bottom,
+      ),
+      "compact XZ, YZ, and XY plots stack without overlap",
     );
     const compactBeamFields = [
       ...documentObject.querySelectorAll(".beam-pattern-fields > .field"),
-    ].map((field) => field.getBoundingClientRect());
+    ].filter((field) => !field.hidden).map((field) => field.getBoundingClientRect());
     assert(
       compactBeamFields.every(
         (rect, index) => index === 0 || rect.top >= compactBeamFields[index - 1].bottom - 1,
       ),
       "compact beam controls stack without clipping",
     );
+    documentObject.querySelector("#beam-pattern-view-3d-button").click();
+    await waitFor(
+      () => documentObject.documentElement.dataset.beamPatternView === "surface" &&
+        documentObject.documentElement.dataset.beamPatternReady === "true" &&
+        !documentObject.querySelector("#beam-pattern-surface-view").hidden &&
+        Number(beamSurface.dataset.sampleCount) > 0,
+      "compact 3D beam surface",
+    );
+    await nextPaint(windowObject);
+    const compactBeamSurfaceRect = beamSurface.getBoundingClientRect();
+    const compactBeamSurfaceCardRect = documentObject.querySelector("#beam-pattern-panel")
+      .getBoundingClientRect();
+    assert(
+      compactBeamSurfaceRect.left >= compactBeamSurfaceCardRect.left - 1 &&
+        compactBeamSurfaceRect.right <= compactBeamSurfaceCardRect.right + 1,
+      "compact 3D beam surface stays inside its analysis card",
+    );
+    assertNear(
+      compactBeamSurfaceRect.width / compactBeamSurfaceRect.height,
+      16 / 10,
+      0.03,
+      "compact 3D beam surface preserves its aspect ratio",
+    );
+    assert(
+      documentObject.documentElement.scrollWidth <=
+        documentObject.documentElement.clientWidth + 1,
+      "3D beam mode has no horizontal overflow at 390px",
+    );
     assert(
       documentObject.querySelector("#array-canvas").getBoundingClientRect().height >= 350,
       "Array canvas remains usable at 390px",
diff --git a/tests/unit/array-builder-canvas.test.js b/tests/unit/array-builder-canvas.test.js
index 16b11c3..40125d2 100644
--- a/tests/unit/array-builder-canvas.test.js
+++ b/tests/unit/array-builder-canvas.test.js
@@ -7,6 +7,7 @@ import {
   hitTestMicrophone,
   keyboardNudgeForKey,
   niceGridStep,
+  projectArrayPosition3d,
 } from "/apps/array-builder/canvas-view.js";
 
 function assertNear(actual, expected, tolerance, label) {
@@ -139,3 +140,29 @@ test("Array canvas grid와 keyboard nudge의 순수 helper가 1/2/5 및 y-up 규
   assertEqual(keyboardNudgeForKey("ArrowDown", 0.002, true).dy, -0.02, "shift multiplies by ten");
   assertEqual(keyboardNudgeForKey("Enter", 0.002), null, "non-arrow key ignored");
 });
+
+test("Array canvas 3D projection은 +Z FRONT와 right-handed XYZ를 보존한다", () => {
+  const frontView = {
+    yaw: 0,
+    pitch: 0,
+    centerPixelX: 200,
+    centerPixelY: 120,
+    centerHorizontal: 0,
+    centerVertical: 0,
+    scale: 100,
+  };
+  const positiveX = projectArrayPosition3d([1, 0, 0], frontView);
+  const positiveZ = projectArrayPosition3d([0, 0, 1], frontView);
+  const positiveY = projectArrayPosition3d([0, 1, 0], frontView);
+  assertNear(positiveX.x, 300, 1e-12, "+X projects right");
+  assertNear(positiveX.y, 120, 1e-12, "+X keeps screen height");
+  assertNear(positiveZ.x, 200, 1e-12, "+Z stays centered horizontally");
+  assertNear(positiveZ.y, 20, 1e-12, "+Z FRONT projects upward");
+  assertNear(positiveY.depth, -1, 1e-12, "+Y supplies front-view depth");
+
+  const edgeView = { ...frontView, pitch: Math.PI / 2 };
+  const edgeY = projectArrayPosition3d([0, 1, 0], edgeView);
+  const edgeZ = projectArrayPosition3d([0, 0, 1], edgeView);
+  assertNear(edgeY.y, 20, 1e-12, "orbiting exposes +Y vertically");
+  assertNear(edgeZ.depth, 1, 1e-12, "orbiting moves +Z onto the depth axis");
+});