Lighting issues on Staircase Meshes

Development Rendering
1

Been having a lot of issues in particular with a set of staircases I have. I will try to give as much information as I can about how things are set up.

First problem seems to be with the dynamic shadows (sometimes? not sure for all or just the character). Its only being recieved by part of the staircase. I have no idea why.


Second problem, there are blotches like this in certain areas. The material being used is solid white and yet it looks like that. Assuming it has to do with UVs but Ive tried making several different UVs and it never seems to work smoothly.

Third issue I’ve had is with tiling the staircases. I’ve read this is a known issue, but I don’t know if its been fixed by now or if there is a solution to the problem I’m unaware of.


These are two different UVs Ive tried on the lightmap channel, both end up with similar results. Too close together? Is that the problem? Not sure.

Here are my world lightmass settings. Let me know if there is anything else Im forgetting. If anyone has any ideas on how to make this work I’d be so thankful, I swear I’ve spent way too long trying to get this to work and its really messing up my scene.

2

Alright so I managed to fix a few issues by doing the following, these are general rules that need to be done when making lightmap UVs. Its not really optional in my opinion:

If there is a sharp angle between faces, dont stitch them together into one UV object. Separate them to prevent bleeding.

When you separate them, make sure you have 4 pixels between each object. You need padding.

SNAP THE VERTICES TO THE GRID. This is the main thing I was missing. If you have the UVs between pixels this WILL cause artifacts. This also means you should make the grid the same size as your lightmap resolution.

These answers are on the web, elsewhere but I wanted to reiterate it for anyone who might be having this issue in the future.

Edit: Still seem to be having a little bit of problems with the dynamic shadow not hitting the vertical part of the steps in some areas. I think it has to do with the angle of the directional light because it only happens when the vertical planes of the steps are parallel to the direction of the light. Probably have to mess aroudn with lightmass settings to get that working.