Shadowbleed - dont know why it happens


i have these 2 meshes (they are the same) connecting at the edges. The mesh always generates this shadow althoug i want them to be seamless.


I tired like 20 different lightmap layouts. Even with a reduced layout (like in picture) i have the same effect. (ofc i tried it with alle compontents too…)

Any advice? :frowning:

It is the edge smoothing instead of the lightmap I think.

That’s a known problem.

1st of all:

I just started few days ago and your UDK and UE4 Tuts really kept me going.

2nd: How can i get rid of it?

You can get rid of it by having space between the islands. Look at this it explains it very well :

Already tried that. As you can see in the pic, there is like 4-8 px to the edge. Even with more it wont work. The LMs i create work good on other objects.

BiggestSimile seems to have the “answer”. So i think that makes it a waiting game :frowning:


Check the smoothing groups in the area if you use Max, or just hard edge the whole thing in Maya.

Feel free to just mail me the FBX and Ill quickly check

Could be the lightmaps also, but considering the gradient is exactly the width of the two triangles there…

In your case you are having an issue with direct lighting, the bug BiggestSimile and i think everybody has is with indirect lighting. So if you unwrap all your faces and seperate them with a margin you should be good, rigth one you have 2 big island but you should have all of your faces separated.

I sent you two files where this happens. Thank you very much for your help.

Thats true. I already checked it with a very basic mesh like in the pic attatched3.jpg. Same effect. Things i tried:

  • Snap UVs to the Grid (vertex wise)
  • made different layouts
  • differnt LM resolutions
  • different spaces
  • different meshes
  • worked through 10 (?) LM and UV Tuts… :smiley:

Import the mesh again, and set Normals to Calculate Normals on import. Fixed probably.

This worked! Thank you very much, you saved the day!