-samples and light leaking

(damocles) #1

I was previously using -super 2 to perform lighting supersampling on my light compiles, but then the safe_malloc error cropped up so I switched to using -samples 3 instead. However, since using -samples I am getting a ton of light leaking under walls, way more than I had when using -super 2. My guess is I have completely misunderstood the -samples parameter and need to change something. Any ideas?

(ydnar) #2

Screenshots?

(damocles) #3

I knew you were gonna ask for screenies. You’ll have to wait for a while now. I just did a test BSP with no lighting, and I’m busy tomorrow. Also, I don’t have any shots of the original, so I’ll have to do two light compiles :confused:

I’m guessing then there’s no known reason for why samples would cause light leakage when super didn’t?

(ydnar) #4

A screenshot of the affected area with the leaking is fine. No need to compile it twice.

The -super sample positions are different than non-super (and -samples) positions. You probably just had a large floor or a thin wall that was right on the cusp.

y

(damocles) #5

On the cusp? On the cusp of what?

The walls are thick in these areas, which is why I was surprised to see the leaking. Most of the walls are 32 units thick, some are only 24. The lighting is done with:

-filter -patchshadows -samples 4 - samplesize 8 -nogrid

None of these areas showed any leakage at all when using -super 2. I also rememebr reading something a while back about using func_groups to alter the lighting process and prevent leaks. How is that done?

(ydnar) #6

Put the floor inside (where it’s leaking to) into func_group entity. Add a “_lightmapscale” key with a value of 0.75 to 0.5.

BTW, -samples 3 is usually as high as you need to go. Over that, the results are only minimally better.

y

(Valhue2) #7

I didnt think that the thickness of wall/floors/ect… made a difference. When I map, i stick to 16 units thick for the walls… Should I make them thicker?

V^2

(damocles) #8

I don’t know for certain, but I had always assumed light leaking was caused because the light at the every edge of the floor can see a light source on the other side (in a purely mathematical sense) and when that edge of light gets blended through to the next light point on the map (the gap size I think depends on the floor size) then you see light leaking. I tend to use thicker walls as it increases the chances that the wall will cover the area of leakage. However, if you really want to stop light leaking, you need to reduce the size of the floor and increase the resolution of the lightmap (in extreme cases).

(UniKorn) #9

Make sure the bottom of your wall is caulked. I know it helps in certain cases, although I don’t know why :frowning: