code: public synchronized void removeAllSceneObjects() {
          final GVRCameraRig rig = getMainCameraRig();
          final GVRSceneObject head = rig.getOwnerObject();
          rig.removeAllChildren();
  
          NativeScene.removeAllSceneObjects(getNative());
          for (final GVRSceneObject child : mSceneRoot.getChildren()) {
              child.getParent().removeChildObject(child);
          }
  
          if (null != head) {
              mSceneRoot.addChildObject(head);
          }
  
          final int numControllers = getGVRContext().getInputManager().clear();
          if (numControllers > 0)
          {
              getGVRContext().getInputManager().selectController();
          }
  
          getGVRContext().runOnGlThread(new Runnable() {
              @Override
              public void run() {
                  NativeScene.deleteLightsAndDepthTextureOnRenderThread(getNative());
              }
          });
      }
docs: Remove all scene objects.