@Override
    public void initialize(RenderManager rm, ViewPort vp) {
        renderManager = rm;
        viewPort = vp;
        postTechniqueName = "PostShadow";
        if(zFarOverride>0 && frustumCam == null){
            initFrustumCam();
        }
    }
Initialize this shadow renderer prior to its first update.

@param rm the render manager
@param vp the viewport
jme3-vr/src/main/java/com/jme3/shadow/AbstractShadowRendererVR.java