@Override
    public void read(JmeImporter im) throws IOException {
        super.read(im);
        InputCapsule ic = im.getCapsule(this);
        spotInnerAngle = ic.readFloat("spotInnerAngle", FastMath.QUARTER_PI / 8);
        spotOuterAngle = ic.readFloat("spotOuterAngle", FastMath.QUARTER_PI / 6);
        computeAngleParameters();
        direction = (Vector3f) ic.readSavable("direction", new Vector3f());
        position = (Vector3f) ic.readSavable("position", new Vector3f());
        spotRange = ic.readFloat("spotRange", 100);
        if (spotRange != 0) {
            this.invSpotRange = 1 / spotRange;
        } else {
            this.invSpotRange = 0;
        }
    }
for internal use only
@return the cosines of the inner and outer angle packed in a float
jme3-core/src/main/java/com/jme3/light/SpotLight.java