UDK - Lightmap problem

S@murai

Hello !
I'm trying to make simple modular pieces for use in UDK, but lightmaping is my enemy.
I've read many articles about creating good lightmap UV's but it looks like I lack some knowledge.
Hope you can help me




fbx
http://www27.zippyshare.com/v/25147528/file.html

Obscura

Have you tried to use bigger lightmap resolution?

S@murai

I set lightmap resolution to 128 for this mesh.

Obscura

I would try and see if its better at 256, but actually your lightmap uvs should be better.

http://udn.epicgames.com/Three/LightMapUnwrapping.html

Its a bit hard to explain, but there are those inward extrudations on those walls. You should have that wall as one uv island on your lightmap uv, and not every face of it as an individual uv island. I see not every face of it is individual, but your lightmap uvs are close to this. You should break the uvs just when it must needed to get more continuous lightmap, like on this picture:


But the page that I linked explains this better.

S@murai

Polycount community helpfull as always. Thank you guys ! I will read trought the page you linked and try to fix thouse UVs.

Obscura

Np. If you still get those blotches after you repaired the lightmap uvs, you can try higher lightmap resolution, or to adjust the level scale in the lightmass section under the world properties.

S@murai

Ok, now this is super strange. I redone UVs and the sould be perfect... and the almost are while mesh is facing lamp,


but when it isn't it makes this strange dark spots. (Resolution cranked up to 256)



New UVs (4px padding between islands, streched vertically as said in material provided)

Obscura

"adjust the level scale in the lightmass section under the world properties." Try 0.25.

S@murai

Wow ! It actually did help Thank you a lot ! You saved my day (really)
Are there any other tweeks I can do to make it look even better aside from world scale and lightmap size ?

Obscura

You can try out the ambient occlusion options, and you can play with the bounce amount, and with the environment color. But there is no "good" settings. They are depending on the many things. If you would apply a diffuse texture to your model, it would hide the pixelated look of the lightmap. Try it out. Just add one, and rebake the lighting.

Edit - Actually there is one thing that would make it look a lot better. You can disable the lightmap compression in the lightmass.ini file. The difference is amazing.

S@murai

This last twaek was amazing ! Now they are super smooth and good looking.
Thank you once more !

Obscura

You're welcome.