@Override
    protected void initFilter(AssetManager manager, RenderManager renderManager, ViewPort vp, int w, int h) {
        material = new Material(manager, "Common/MatDefs/Blur/RadialBlur.j3md");
    }
sets the sample strength default is 2.2

@param sampleStrength the desired strength (default=2.2)
jme3-effects/src/main/java/com/jme3/post/filters/RadialBlurFilter.java