Fix forceCompilation with multimat

dist/preview release/babylon.max.js

@@ -48804,6 +48804,7 @@ var BABYLON;
             var _this = _super.call(this, name, scene, true) || this;
             scene.multiMaterials.push(_this);
             _this.subMaterials = new Array();
+            _this.storeEffectOnSubMeshes = true; // multimaterial is considered like a push material
             return _this;
         }
         Object.defineProperty(MultiMaterial.prototype, "subMaterials", {

dist/preview release/customConfigurations/minimalGLTFViewer/babylon.max.js

@@ -35833,6 +35833,7 @@ var BABYLON;
             var _this = _super.call(this, name, scene, true) || this;
             scene.multiMaterials.push(_this);
             _this.subMaterials = new Array();
+            _this.storeEffectOnSubMeshes = true; // multimaterial is considered like a push material
             return _this;
         }
         Object.defineProperty(MultiMaterial.prototype, "subMaterials", {

src/Materials/babylon.multiMaterial.ts

@@ -16,6 +16,8 @@
             scene.multiMaterials.push(this);
 
             this.subMaterials = new Array<Material>();
+
+            this.storeEffectOnSubMeshes = true; // multimaterial is considered like a push material
         }
 
         private _hookArray(array: Material[]): void {