@Override
    protected void clearMaterialParameters(Material material) {
        material.clearParam("Splits");
        material.clearParam("FadeInfo");
        material.clearParam("LightDir");
    }
Sets the light to use to cast shadows
@param light a DirectionalLight
jme3-vr/src/main/java/com/jme3/shadow/DirectionalLightShadowRendererVR.java