Fixes issue #12465 (Entity Tracking broken)

CHANGES.md

@@ -1,5 +1,13 @@
 # Change Log
 
+## 1.128 - 2025-04-01
+
+### @cesium/engine
+
+#### Fixes :wrench:
+
+- Fixed broken Entity Tracking [sandcastle](https://sandcastle.cesium.com/?src=Entity%20tracking.html). [#12467](https://github.com/CesiumGS/cesium/pull/12467)
+
 ## 1.127 - 2025-03-03
 
 ### @cesium/engine

packages/engine/Source/Widget/CesiumWidget.js

@@ -1134,6 +1134,8 @@ CesiumWidget.prototype._updateCanAnimate = function (isUpdated) {
   this._clock.canAnimate = isUpdated;
 };
 
+const boundingSphereScratch = new BoundingSphere();
+
 /**
  * @private
  */
@@ -1146,15 +1148,15 @@ CesiumWidget.prototype._onTick = function (clock) {
   }
 
   const entityView = this._entityView;
-  if (defined(entityView) && defined(entityView.boundingSphere)) {
+  if (defined(entityView)) {
     const trackedEntity = this._trackedEntity;
     const trackedState = this._dataSourceDisplay.getBoundingSphere(
       trackedEntity,
       false,
-      entityView.boundingSphere,
+      entityView.boundingSphere ?? boundingSphereScratch,
     );
     if (trackedState === BoundingSphereState.DONE) {
-      entityView.update(time, entityView.boundingSphere);
+      entityView.update(time);
     }
   }
 };

packages/engine/Specs/DataSources/EntityViewSpec.js

@@ -89,43 +89,74 @@ describe(
       expect(view.scene.camera.position).toEqualEpsilon(sampleOffset, 1e-10);
     });
 
-    it("uses entity bounding sphere", function () {
-      const sampleOffset = new Cartesian3(
-        -1.3322676295501878e-15,
-        -7.348469228349534,
-        7.3484692283495345,
-      );
+    it("uses provided bounding sphere", function () {
+      const bs = new BoundingSphere(new Cartesian3(3, 4, 5), 6);
+      scene.camera.viewBoundingSphere(bs);
+      const positionWC = scene.camera.positionWC.clone();
+
       const entity = new Entity();
       entity.position = new ConstantPositionProperty(
         Cartesian3.fromDegrees(0.0, 0.0),
       );
       const view = new EntityView(entity, scene, undefined);
-      view.update(
-        JulianDate.now(),
-        new BoundingSphere(new Cartesian3(3, 4, 5), 6),
-      );
-      expect(view.scene.camera.position).toEqualEpsilon(sampleOffset, 1e-10);
+      view.update(JulianDate.now(), bs);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC, 1e-10);
 
       entity.trackingReferenceFrame = TrackingReferenceFrame.INERTIAL;
-      view.update(
-        JulianDate.now(),
-        new BoundingSphere(new Cartesian3(3, 4, 5), 6),
-      );
-      expect(view.scene.camera.position).toEqualEpsilon(sampleOffset, 1e-10);
+      view.update(JulianDate.now(), bs);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC, 1e-10);
 
       entity.trackingReferenceFrame = TrackingReferenceFrame.VELOCITY;
-      view.update(
-        JulianDate.now(),
-        new BoundingSphere(new Cartesian3(3, 4, 5), 6),
-      );
-      expect(view.scene.camera.position).toEqualEpsilon(sampleOffset, 1e-10);
+      view.update(JulianDate.now(), bs);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC, 1e-10);
 
       entity.trackingReferenceFrame = TrackingReferenceFrame.ENU;
-      view.update(
-        JulianDate.now(),
-        new BoundingSphere(new Cartesian3(3, 4, 5), 6),
+      view.update(JulianDate.now(), bs);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC, 1e-10);
+    });
+
+    it("jumps to updated bounding sphere", function () {
+      const bs1 = new BoundingSphere(new Cartesian3(1, 2, 3), 4);
+      scene.camera.viewBoundingSphere(bs1);
+      const positionWC1 = scene.camera.positionWC.clone();
+
+      const bs2 = new BoundingSphere(new Cartesian3(3, 4, 5), 4);
+      scene.camera.viewBoundingSphere(bs2);
+      const positionWC2 = scene.camera.positionWC.clone();
+
+      const entity = new Entity();
+      entity.position = new ConstantPositionProperty(
+        Cartesian3.fromDegrees(0.0, 0.0),
       );
-      expect(view.scene.camera.position).toEqualEpsilon(sampleOffset, 1e-10);
+      const view = new EntityView(entity, scene, undefined);
+      view.update(JulianDate.now(), bs1);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC1, 1e-10);
+
+      view.boundingSphere.center = bs2.center;
+      view.update(JulianDate.now());
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC2, 1e-10);
+    });
+
+    it("jumps to new bounding sphere", function () {
+      const bs1 = new BoundingSphere(new Cartesian3(1, 2, 3), 4);
+      scene.camera.viewBoundingSphere(bs1);
+      const positionWC1 = scene.camera.positionWC.clone();
+
+      const bs2 = new BoundingSphere(new Cartesian3(3, 4, 5), 4);
+      scene.camera.viewBoundingSphere(bs2);
+      const positionWC2 = scene.camera.positionWC.clone();
+
+      const entity = new Entity();
+      entity.position = new ConstantPositionProperty(
+        Cartesian3.fromDegrees(0.0, 0.0),
+      );
+      const view = new EntityView(entity, scene, undefined);
+      view.update(JulianDate.now(), bs1);
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC1, 1e-10);
+
+      view.boundingSphere = bs2;
+      view.update(JulianDate.now());
+      expect(scene.camera.positionWC).toEqualEpsilon(positionWC2, 1e-10);
     });
 
     it("uses entity viewFrom if available and boundingsphere is supplied", function () {