Update the AABB during rendering only if it hasn't already been updated in the current frame

src/framework/lightmapper/lightmapper.js

@@ -813,7 +813,7 @@ class Lightmapper {
 
             const meshInstances = bakeNode.meshInstances;
             for (let i = 0; i < meshInstances.length; i++) {
-                if (meshInstances[i]._isVisible(shadowCam)) {
+                if (meshInstances[i]._isVisible(shadowCam, this.renderer._aabbUpdateIndex)) {
                     nodeVisible = true;
                     break;
                 }

src/scene/mesh-instance.js

@@ -376,6 +376,9 @@ class MeshInstance {
      */
     _calculateSortDistance = null;
 
+    /** @private */
+    _aabbUpdateIndex = 0;
+
     /**
      * Create a new MeshInstance instance.
      *
@@ -942,10 +945,11 @@ class MeshInstance {
      * date, which forward-renderer takes care of. This function should not be called elsewhere.
      *
      * @param {Camera} camera - The camera to test visibility against.
+     * @param {number} aabbUpdateIndex - An index used to detect if AABB has already been updated this frame.
      * @returns {boolean} - True if the mesh instance is visible by the camera, false otherwise.
      * @ignore
      */
-    _isVisible(camera) {
+    _isVisible(camera, aabbUpdateIndex) {
 
         if (this.visible) {
 
@@ -954,8 +958,11 @@ class MeshInstance {
                 return this.isVisibleFunc(camera);
             }
 
-            _tempSphere.center = this.aabb.center;  // this line evaluates aabb
-            _tempSphere.radius = this._aabb.halfExtents.length();
+            const aabb = this._aabbUpdateIndex === aabbUpdateIndex ? this._aabb : this.aabb; // this line evaluates aabb
+            this._aabbUpdateIndex = aabbUpdateIndex;
+
+            _tempSphere.center = aabb.center;
+            _tempSphere.radius = aabb.halfExtents.length();
 
             return camera.frustum.containsSphere(_tempSphere) > 0;
         }

src/scene/renderer/renderer.js

@@ -158,6 +158,9 @@ class Renderer {
 
     blueNoise = new BlueNoise(123);
 
+    /** @private */
+    _aabbUpdateIndex = 0;
+
     /**
      * Create a new instance.
      *
@@ -916,7 +919,7 @@ class Renderer {
             const drawCall = drawCalls[i];
             if (drawCall.visible) {
 
-                const visible = !doCull || !drawCall.cull || drawCall._isVisible(camera);
+                const visible = !doCull || !drawCall.cull || drawCall._isVisible(camera, this._aabbUpdateIndex);
                 if (visible) {
                     drawCall.visibleThisFrame = true;
 
@@ -1131,6 +1134,8 @@ class Renderer {
         const cullTime = now();
         // #endif
 
+        this._aabbUpdateIndex++;
+
         const { scene } = this;
 
         this.processingMeshInstances.clear();

src/scene/renderer/shadow-renderer.js

@@ -142,7 +142,7 @@ class ShadowRenderer {
             const meshInstance = meshInstances[i];
 
             if (meshInstance.castShadow) {
-                if (!meshInstance.cull || meshInstance._isVisible(camera)) {
+                if (!meshInstance.cull || meshInstance._isVisible(camera, this.renderer._aabbUpdateIndex)) {
                     meshInstance.visibleThisFrame = true;
                     visible.push(meshInstance);
                 }