Set missing parentId in Mesh.serialize() for instances

dist/preview release/what's new.md

@@ -168,6 +168,7 @@
 - Do not throw error when updating a controller with no left stick ([TrevorDev](https://github.com/TrevorDev))
 - Exiting VR can result in messed up view ([TrevorDev](https://github.com/TrevorDev))
 - Dispose existing gazeTrackers when setting a new one, remove pivot matrix of meshes using boundingBoxGizmo ([TrevorDev](https://github.com/TrevorDev))
+- Set missing parentId in Mesh.serialize() for instances ([julien-moreau](https://github.com/julien-moreau))
 
 ### Core Engine
 

src/Mesh/babylon.mesh.ts

@@ -2361,6 +2361,11 @@
                     position: instance.position.asArray(),
                     scaling: instance.scaling.asArray()
                 };
+
+                if (instance.parent) {
+                    serializationInstance.parentId = instance.parent.id;
+                }
+                
                 if (instance.rotationQuaternion) {
                     serializationInstance.rotationQuaternion = instance.rotationQuaternion.asArray();
                 } else if (instance.rotation) {