Expose the camera and Viewer classes

Viewer/src/index.ts

@@ -1,3 +1,4 @@
+import { DefaultViewer } from './viewer/defaultViewer';
 import { AbstractViewer } from './viewer/viewer';
 
 /**
@@ -25,4 +26,4 @@ setTimeout(() => {
 });
 
 // public API for initialization
-export { InitTags };
+export { InitTags, DefaultViewer, AbstractViewer };

Viewer/src/viewer/defaultViewer.ts

@@ -9,7 +9,7 @@ window['BABYLON'] = BABYLON;
 
 export class DefaultViewer extends AbstractViewer {
 
-    private camera: ArcRotateCamera;
+    public camera: ArcRotateCamera;
 
     public initScene(): Promise<Scene> {
         return super.initScene().then(() => {