private void addPhotonAtAngle(float x, float y, float angle) {
		float freq = lightSource.isMonochromatic() ? lightSource.getFrequency() : LightSource.getRandomFrequency();
		Photon p = new Photon(x, y, freq);
		p.setAngle(angle);
		p.setModel(this);
		p.setFromLightSource(true);
		addPhoton(p);
	}