Hi,

I wonder how lights that illuminate the same surface behave in reality. Do they add up linearily, or the most donating light simply negates the other? How do you implement lights combining in your deffered blended renderes?

Thanks a lot

I think it's safe to model light contribution as adding linearly, unless you're trying to model quantum wave interference effects

In my deferred renderers I simply add the contribution of each light.

The only thing I think you should be aware of is this: make sure you do your lighting calculations in linear space, not sRGB space. sRGB space is not linear.

I think it's safe to model light contribution as adding linearly, unless you're trying to model quantum wave interference effects

Actually, even in that case it's additive, but you may have to use complex numbers to describe how much light hits a particular spot (a magnitude and a phase, if you will).