Composite Map Blend Modes Math

[robert3dsmax]

Dear users,

I write a kind of generic fx-shader that mimics most of the VrayMaterial for use in interactive scenarios.

Currently I code the several blend modes for the composite map, and I got all of them except one:

Spotlight Blend.

In the documentation it says:

"Same as Spotlight but also adds ambient illumination to B".

So Spotlight itself is this:

"like multiply, bit with twice the brightness"

result = 2 * image1 * image2

So the code I tried for spotlight blend is this:

result = 2 * image1 * (image2 + 0.5)

But the result is a bit too bright. It seems not to be as simple. Does anybody have the code for spotlight blend? I trade some other blend modes if somebody wants to know ;).

Thanks and best regards

Robert

[robert3dsmax]

solved, code is in the 3dsmax SDK.