Diffuse Reflection

Idiff

= kd Il cos [theta] = kd Il (N . L)

Itotal	= ka Ia +	kd Il (N . L)
	- ambient -	- diffuse -

	Adding color (OdR, OdG, OdB)
=>
	IR = IaR ka OdR + IlR kd OdR (N . L)
	IG = IaG ka OdG + IlG kd OdG (N . L)
	IB = IaB ka OdB + IlB kd OdB (N . L)