Introduce ModelData class

packages/model-viewer/src/three-components/ModelData.ts

@@ -0,0 +1,17 @@
+import {Object3D} from 'three';
+
+/**
+ * A THREE.Scene object that takes a Model and CanvasHTMLElement and
+ * constructs a framed scene based off of the canvas dimensions.
+ * Provides lights and cameras to be used in a renderer.
+ */
+export class ModelData extends Object3D {
+// ModelScene is going to have child of this types
+public url: string|null = null;
+
+constructor(url: string) {
+    super();
+    this.url = url;
+    console.log("ModelData constructor is called");
+}
+}

packages/model-viewer/src/three-components/ModelScene.ts

@@ -21,6 +21,7 @@ import {$currentGLTF, $model, $originalGltfJson} from '../features/scene-graph.j
 import {$nodeFromIndex, $nodeFromPoint} from '../features/scene-graph/model.js';
 import ModelViewerElementBase, {$renderer, EffectComposerInterface, RendererInterface} from '../model-viewer-base.js';
 import {ModelViewerElement} from '../model-viewer.js';
+import {ModelData} from './ModelData.js';
 import {normalizeUnit} from '../styles/conversions.js';
 import {NumberNode, parseExpressions} from '../styles/parsers.js';
 
@@ -65,6 +66,7 @@ const ndc = new Vector2();
  * Provides lights and cameras to be used in a renderer.
  */
 export class ModelScene extends Scene {
+  public modelData: ModelData;
   public element: ModelViewerElement;
   public canvas: HTMLCanvasElement;
   public annotationRenderer = new CSS2DRenderer();
@@ -120,6 +122,8 @@ export class ModelScene extends Scene {
   constructor({canvas, element, width, height}: ModelSceneConfig) {
     super();
 
+    this.modelData = new ModelData("url.glb");
+
     this.name = 'ModelScene';
 
     this.element = element as ModelViewerElement;