Weird Lightmap issue?

Development Rendering
,
1

Hi guys,
I am working on creating modular assets, and the first asset I am making is a very simple wall.

I have managed to get the wall to line up seamlessly and it looks great, however I have a weird light map issue with the shadows that it projects.

Here is an image of how it should look like. This is my wall before I bake the lighting.

1 (1).JPG
1 (1).JPG774×828 53.6 KB

And after I bake the lighting, the shadow goes all squiggly and bleeds a little bit infront of the wall on the ground:

2.JPG
2.JPG946×879 66.5 KB

I have done a lot of research but can’t figure out why this is happening. This is what my model looks like in 3ds Max.

3.JPG
3.JPG795×739 19.2 KB

And this is what my custom lightmap I made in 3ds Max looks like:

4.JPG
4.JPG1919×1038 286 KB

I set the light map grid to have 64 pixels and I made sure I snap the vertices to the gird. I also made sure I have a 3 to 4 pixel padding. I am so close to having a perfect modular asset. What is causing this issue? I have already watched “The World Of Level Design” tutorial regarding lightmaps and bleeding. Any help would be greatly appreciated!

2

that’s caused by the lighmap resolution on the floor being to low and not by a problem with your wall mesh, you just need to increase the lightmap resolution of your floor to fix your issue (unless the floor is BSP in which case you need to reduce the value).

hope that helps:)

3

A large floor that can’t have blobby shadows is going to be need a 512 light map. Also read this post

5

Ok thanks and so my lightmap for my wall should be 62 by 62 instead of 64 by 64 for it to work perfectly?

6

Thats great news! So if I model a square thats used for the floor that replaces the bsp brush it should in theory have much better light mapping?

7

Yup, 62x62 if you want to use 64. Also you should try to make each wall more than one pixel thick. Stretching lightmap UV’s isn’t really an issue, so feel free to make something 3x wider just because there’s room to. Also there’s no need to have padding around the edge since the engine does that by itself.