public void setSampleRadius(float sampleRadius) {
        this.sampleRadius = sampleRadius;
        if (ssaoMat != null) {
            ssaoMat.setFloat("SampleRadius", sampleRadius);
        }

    }
Sets the radius of the area where random samples will be picked default 5.1f 

@param sampleRadius the desired radius (default=5.1)
jme3-effects/src/main/java/com/jme3/post/ssao/SSAOFilter.java