@Override
    public void initialize(RenderManager rm, ViewPort vp) {
        renderManager = rm;
        viewPort = vp;
        postTechniqueName = "PostShadow";
    }
sets the shadow compare mode see {@link CompareMode} for more info

@param compareMode the desired mode (not null)
jme3-core/src/main/java/com/jme3/shadow/PssmShadowRenderer.java