Normal/Lighting Error?

[LiqzZ]

I have a problem with some of the brick walls in my level, for some reason the normal only seems to appear on half of my mesh. I have no idea what's causing the problem. The mesh is 2 polys, one for the top and one for the front (it has no backfaces which may be attributed to the error. I have turned on two sided lighting in the mesh properties but this doesn't fix it). The material looks fine without the normal map but with it this error appears. Here's what it looks like ingame:



Here's another error in the same level, the normal looks fine on the right wall where the light directly hits the wall but on the left wall it's messed up.



Here's the Normal:



And here's the material in UDK



I would give more information but i'm not sure what to give as I have no idea where the error is coming from. Any ideas?

[LiqzZ]

Update: Tried making the material two sided but to no avail

[obihb]

I think you'll need actual polygons there. Using 2 sided does not really do the trick. I've had these problems and the way I fix them is to create models that are purely used for shadow casting and they are not rendered during game play. An easy fix is to simply build your wall as a complete box. If back faces are never seen, then just map them in a tiny area on your texture and light map. I'm not sure if there is another way to fix this. Even referencing the Epic content you'll see that every single model they make is a full (air tight) model.

[darthviper107]

I don't think that's the issue. Make sure you've got correct lightmap UV's and build your lighting, also try increasing the lightmap resolution.

[JessieG]

Also, add a specular map. It helps the normal map a lot.