Fix the bounding box of instances (#8713)

* Fix the bounding box of instances

* Add missing import

dist/preview release/what's new.md

@@ -277,6 +277,7 @@
 - Fix an issue causing views to render blank when scene rendering is skipped for a given iteration of the render loop ([elInfidel](https://github.com/elInfidel))
 - Fix docs Matrix.RotationYawPitchRoll and Matrix.RotationYawPitchRollToRef ([VSerain](https://github.com/VSerain))
 - Fix issue in `GLTFLoader._updateBoneMatrices()` where bone rest position was not set. ([drigax](https://github.com/drigax))
+- Fix the bounding box of instances that does not match the instance position / rotation / scaling ([Popov72](https://github.com/Popov72))
 
 ## Breaking changes
 - `FollowCamera.target` was renamed to `FollowCamera.meshTarget` to not be in conflict with `TargetCamera.target` ([Deltakosh](https://github.com/deltakosh))

src/Meshes/instancedMesh.ts

@@ -11,6 +11,7 @@ import { DeepCopier } from "../Misc/deepCopier";
 import { TransformNode } from './transformNode';
 import { Light } from '../Lights/light';
 import { VertexBuffer } from './buffer';
+import { BoundingInfo } from '../Culling/boundingInfo';
 
 Mesh._instancedMeshFactory = (name: string, mesh: Mesh): InstancedMesh => {
     let instance = new InstancedMesh(name, mesh);
@@ -409,6 +410,19 @@ export class InstancedMesh extends AbstractMesh {
         return this._sourceMesh._generatePointsArray();
     }
 
+    /** @hidden */
+    public _updateBoundingInfo(): AbstractMesh {
+        const effectiveMesh = this as AbstractMesh;
+        if (this._boundingInfo) {
+            this._boundingInfo.update(effectiveMesh.worldMatrixFromCache);
+        }
+        else {
+            this._boundingInfo = new BoundingInfo(this.absolutePosition, this.absolutePosition, effectiveMesh.worldMatrixFromCache);
+        }
+        this._updateSubMeshesBoundingInfo(effectiveMesh.worldMatrixFromCache);
+        return this;
+    }
+
     /**
      * Creates a new InstancedMesh from the current mesh.
      * - name (string) : the cloned mesh name