@Override
    public void write(JmeExporter ex) throws IOException {
        super.write(ex);
        OutputCapsule oc = ex.getCapsule(this);
        oc.write(whitePoint, "whitePoint", DEFAULT_WHITEPOINT.clone());
    }
Get the scene white point.

@return The intensity of the brightest part of the scene.
jme3-effects/src/main/java/com/jme3/post/filters/ToneMapFilter.java