C++ Unreal lecture n. 97 - light bleeding through static meshes

[ArcaneSunset]

Hello, sorry if this has been asked before, but I couldn’t find the topic on the forum.

I’ve tried the BSP challenge (overdone it, my level ended up being 2x as big as the instructor’s level ) and, moving on to the lightning lecture, I noticed a thing that I found difficult to manage: light on my BSP derived static meshes.

As you can see, the static mesh of the wall with a doorframe is having light intrusions underneath and some spots over certain areas, coming from the sky light from outside. I know the instructor said that it’s not ought to be perfect, but I am curious as to how (or even if) I can fix these problems.

I was browsing forums endlessly to understand what’s the problem, some suggested to play a bit with LOD Build Settings and General Settings of the mesh, others said that the only thing that matters is lightmap resolution… I tried to dedicate some days to each solution and a few combinations of both, to no avail, just to mitigate the issue that remained.

Is there any way to solve this or this is normal with static meshes generated from BSPs?

[DanM]

Could be the UVs or lightmap resolution

In the details panel of the mesh within the static mesh editor try increasing the Light Map Resolution to 1024 and/or the Light Map Coordinate Index to 1.

[ArcaneSunset]

Thank you, I’ll try this after work and let you know. Is there a rule of thumb on how high should I set lightmap resolution in this case?

[DanM]

No idea to be completely honest. I just use 1024

[ArcaneSunset]

oh well, that sounds about right!

Ok, I tried to set lightmap resolution to that number, since I already set Lightmap coordinates index to 1 before as part of a fix and, judging by the changes, it seems like the right direction to take. There still some light coming in, but I suppose it all amounts to little adjustments in resolution, tweaking model intersections and importing your own meshes from Blender.

Thank you very much!