Assumption for Diffuse Reflection - Polygon Rendering
i) the diffuse reflections by the surface are scattered along with equal intensity in each direction, independent of viewing direction. These surfaces are termed as "ideal diffuse reflectors" or "Lambertion reflectors" Qradiant elevated energy from any point on the surface is directed via "LAMBERTS COSINE LAW" which is, in diffuse reflection ease the intensity of reflected light (I) is a cos θ and
(ii) Kd ⇔ Ka (usually).