@Override
    public void write(JmeExporter exporter) throws IOException {
        super.write(exporter);
        OutputCapsule capsule = exporter.getCapsule(this);

        capsule.write(width, "width", 0f);
        capsule.write(height, "height", 0f);
    }
Serializes to the specified exporter, for example when saving to a J3O
file. The current instance is unaffected.

@param exporter the exporter to use (not null)
@throws IOException from the exporter
jme3-vr/src/main/java/com/jme3/scene/CenterQuad.java