Extract doRender() so that subclasses can customize rendering

src/viewer.ts

@@ -111,10 +111,14 @@ export class SkinViewer {
 			return;
 		}
 		this.animations.runAnimationLoop(this.playerObject);
-		this.renderer.render(this.scene, this.camera);
+		this.doRender();
 		window.requestAnimationFrame(() => this.draw());
 	}
 
+	protected doRender() {
+		this.renderer.render(this.scene, this.camera);
+	}
+
 	setSize(width: number, height: number) {
 		this.camera.aspect = width / height;
 		this.camera.updateProjectionMatrix();