How does splotchfix work?

(rgoer) #1

I saw splotchfix mentioned in that old thread that was revived this morning, and got to wondering: does splotchfix still work? If so, what does it do, exactly? I mean, I assume it “fixes splotches” in the lightmap, but how does it do this? And is there a global switch for it, instead of manually adding q3map_splotchfix to every shader that gets lightmapped?

(ydnar) #2

Any lightmap pixels (luxels) that are completely black get new average values from their neighbors.

This can help alleviate “shadow-acne” on certain types of lightmapped surfaces.

However, it’s a crutch, and tends to destroy intentional dark shadows, so use with care, or use q3map_lightmapSampleOffset to offset the sampling point away from the surface a bit.

y

(rgoer) #3

Ah, so that’s what q3map_lightmapsampleoffset does. Thanks!