code: public void setScale(final float scale) {
          if (equal(mScale, scale) != true) {
              Log.d(TAG, "setScale(): old: %.2f, new: %.2f", mScale, scale);
              mScale = scale;
              setScale(mSceneRootObject, scale);
              setScale(mMainCameraRootObject, scale);
              setScale(mLeftCameraRootObject, scale);
              setScale(mRightCameraRootObject, scale);
              for (OnScaledListener listener : mOnScaledListeners) {
                  try {
                      listener.onScaled(scale);
                  } catch (Exception e) {
                      e.printStackTrace();
                      Log.e(TAG, e, "setScale()");
                  }
              }
          }
      }
docs: Scale all widgets in Main Scene hierarchy
  @param scale