@Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();

        for (VRTScene scene : mSceneArray) {
            scene.forceCascadeTearDown();
        }

        /**
         * If we're exiting Viro and destroying the renderer, notify the MaterialManager so that if
         * the application doesn't get killed, then the next time Viro starts, we know to reload the
         * materials.
         */
        MaterialManager materialManager = mReactContext.getNativeModule(MaterialManager.class);
        materialManager.shouldReload();

        if (mViroView != null) {
            mViroView.onActivityStopped(mReactContext.getCurrentActivity());
            mViroView.dispose();
            mViroView = null;
        }
    }
We may need to reload the materials if the renderer was destroyed, but the app was not
and the user resumed.
android/viro_bridge/src/main/java/com/viromedia/bridge/component/VRT3DSceneNavigator.java