fix: keep camera geometry aligned with trajectories

apps/acoustic-camera/model.js

@@ -62,10 +62,30 @@ export function shiftSceneDistance(scene, experiment, nextDistance) {
   const previousDistance = experiment.scan.z;
   const delta = nextDistance - previousDistance;
   experiment.scan.z = nextDistance;
-  for (const source of scene.sources) source.position[2] += delta;
+  for (const source of scene.sources) {
+    source.position[2] += delta;
+    for (const keyframe of source.trajectory ?? []) keyframe.position[2] += delta;
+  }
   if (scene.image?.plane) scene.image.plane.z += delta;
 }
 
+function sourceGeometryPositions(scene) {
+  return (scene.sources ?? []).flatMap((source) => {
+    const candidates = [source.position, ...(source.trajectory ?? []).map(({ position }) => position)];
+    const uniquePositions = new Map();
+    for (const position of candidates) {
+      if (
+        Array.isArray(position) &&
+        position.length === 3 &&
+        position.every(Number.isFinite)
+      ) {
+        uniquePositions.set(position.join(","), position);
+      }
+    }
+    return [...uniquePositions.values()];
+  });
+}
+
 export function alignExperimentToScene(experiment, scene) {
   const plane = scene.image?.plane;
   if (plane) {
@@ -79,13 +99,7 @@ export function alignExperimentToScene(experiment, scene) {
     return "image-plane";
   }
 
-  const positions = (scene.sources ?? [])
+  const positions = sourceGeometryPositions(scene);
-    .map((source) => source.position)
-    .filter((position) =>
-      Array.isArray(position) &&
-      position.length === 3 &&
-      position.every(Number.isFinite),
-    );
   if (positions.length === 0) return "unchanged";
 
   const paddedBounds = (values) => {

tests/unit/camera.test.js

@@ -249,7 +249,14 @@ test("Camera workload counts unique overlapping FFT bins", () => {
 test("Camera distance shift keeps the scene and scan on one z plane", () => {
   const scene = {
     sources: [
-      { id: "one", position: [0.1, -0.2, 2] },
+      {
+        id: "one",
+        position: [0.1, -0.2, 2],
+        trajectory: [
+          { time: 0, position: [0.1, -0.2, 2] },
+          { time: 1, position: [0.6, 0.3, 2.5] },
+        ],
+      },
       { id: "two", position: [-0.3, 0.4, 2.5] },
     ],
     image: { plane: { z: 2, xMin: -1, xMax: 1, yMin: -1, yMax: 1 } },
@@ -260,6 +267,16 @@ test("Camera distance shift keeps the scene and scan on one z plane", () => {
 
   assertEqual(experiment.scan.z, 3.25, "scan z");
   assertEqual(scene.sources[0].position.join(","), "0.1,-0.2,3.25", "first source z shift");
+  assertEqual(
+    scene.sources[0].trajectory[0].position.join(","),
+    "0.1,-0.2,3.25",
+    "first trajectory keyframe z shift",
+  );
+  assertEqual(
+    scene.sources[0].trajectory[1].position.join(","),
+    "0.6,0.3,3.75",
+    "later trajectory keyframe retains relative depth",
+  );
   assertEqual(scene.sources[1].position.join(","), "-0.3,0.4,3.75", "relative source depth retained");
   assertEqual(scene.image.plane.z, 3.25, "background image plane z shift");
 });
@@ -302,6 +319,26 @@ test("Camera aligns an experiment to an imported scene without changing grid res
   assertNear(experiment.scan.yMax, 0.45, 1e-12, "source y maximum with padding");
   assertEqual(experiment.scan.columns, 32, "columns retained after source fallback");
   assertEqual(experiment.scan.rows, 24, "rows retained after source fallback");
+
+  const movingScene = {
+    sources: [
+      {
+        id: "moving",
+        position: [-2, -3, 1],
+        trajectory: [
+          { time: 0, position: [-2, -3, 1] },
+          { time: 1, position: [4, 5, 9] },
+        ],
+      },
+      { id: "fixed", position: [0, 1, 5] },
+    ],
+  };
+  assertEqual(alignExperimentToScene(experiment, movingScene), "source-bounds", "trajectory fallback");
+  assertEqual(experiment.scan.z, 5, "trajectory depths contribute to median scan depth");
+  assertNear(experiment.scan.xMin, -2.9, 1e-12, "trajectory x minimum with padding");
+  assertNear(experiment.scan.xMax, 4.9, 1e-12, "trajectory x maximum with padding");
+  assertNear(experiment.scan.yMin, -4.2, 1e-12, "trajectory y minimum with padding");
+  assertNear(experiment.scan.yMax, 6.2, 1e-12, "trajectory y maximum with padding");
 });
 
 test("Camera result document is schema-safe and linked to its snapshot", async () => {