private void updateClipPlanes() {
        reflectionClipPlane = plane.clone();
        reflectionClipPlane.setConstant(reflectionClipPlane.getConstant() + reflectionClippingOffset);
        refractionClipPlane = plane.clone();
        refractionClipPlane.setConstant(refractionClipPlane.getConstant() + refractionClippingOffset);

    }
Set the water plane using an origin (location) and a normal (reflection direction).
@param origin Set to 0,-6,0 if your water quad is at that location for correct reflection
@param normal Set to 0,1,0 (Vector3f.UNIT_Y) for normal planar water
jme3-effects/src/main/java/com/jme3/water/SimpleWaterProcessor.java