Question about overlays.

Hello, i am currently working on a map and i wanted to ask do overlays count as visleafs?
So should i use more decals than overlays? I have ALOT of overlays currently cause i want the map to look dirty, i have increased the lightmap scales etc to avoid getting the “Warning: Vis decompression overrun”. The map is very large, every unseen face is nodrawn and func_detail is used but i need to know what are the differences between overlays and decals, and can they cause the error.
The map works now but im only halfway trough.

Many thanks to anyone helpful!

E: Also, gimme tips on optimization on visleafs

Overlays are way more expensive then decals because they are much more dynamic. For a dirty map, you should just use dirty textures, with a decal here and there. Overlays are best used when spread over multiple adjacent faces such as a corner.

Thanks i wuw u :)<3

E: FUUUUUUUUU SO MANY OVERLAYS TO REMOVE.

Overlays do not split visleaves. However, if you make overlays too large or use too many, the map fails to compile. The difference between overlays and decals is that overlays can be stretched, resized, rotated, and changed. Decals are pretty much come as they are. If the decal looks good enough, then use it. If not, use an overlay.

Also, if you want the map to look dirty, then you might want to use dirtier looking textures instead of dirtying up clean ones. Each overlay is another 2+ triangles to render.

EDIT: Ninja’d damnit

You were helpful too, thanks!

Do not put overlays on faces with very low lightmap scales, then you will get the error that it´s touching too many faces and your map will fail to update after compile, it will seem fine in the compiler, but it won´t update.

Also there´s nothing wrong with using many overlays, they are not that expensive. I have over 300 in my map and 512 is the limit, no problems what so ever.

Also, I will strengthen the fact that it doesn´t cut up visleafs (it´s been said but it´s worth to repeate).