Why can't we add ambient shading to our z-buffer algorithm? It seems to me as if ambient shading is no different as adding an extra layer of color since every pixel will get the same constant color
In the case of multiple light sources, is I_a implemented as a sum of intensities? And does I_a factor in distances of lighting sources or do we just hand wave that away. I'd be curious to see how changing k_a affects how real the scene looks.