The dgs (left sphere) is obviously much darker - just a matter of settings you'd say. So let's tweak them a bit - let's increase the dgs' diffuse to total white:
Better, but still very dissatisfying - and the 'Color' attribute of our phong is still darker (0.5 value!) than the dgs' diffuse color. What is the cause of this discrepancy? Having a look at the dgs shader sources, which are freely availabe we see the reason for this. A line of comment says (and it's also applied later on in the code):
[code]* m->diffuse is reflectance rho (0 <= rho <= 1). BRDF f_r = rho/pi.[/code]
This means, the radiance (rho), is being divided by pi (approx. 3.1415etc...). Uhm..
What does radiance actually mean? Here's some useful links describing the term:
So radiance is used to indicate how much power will be received by an optical system looking at the surface from a certain angle. The division by pi will be explained later on.
How could we achieve what the dgs is internally doing, with our Maya shader? You guessed it, let's use the 'Diffuse' attribute of our Lambert material, which acts as a simple multiplier to the 'Color' value. Since we cant literally divide, we need to multiply by the fraction: 1/pi (approx. 0.318). Let's do it:
Oops, what went wrong? Sure, we set our dgs' diffuse color to white before, let's do so with our phong.
Set the phong 'Color' to total white:
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