modular light bleed
So like everyone else i cant find any info on stopping the light bleed when using modular meshes. One person suggested using LPV as opposed to lightmass, is there no easy solution to this?
asked Nov 19 '14 at 09:58 PM in Using UE4
I've spent a little bit and setup a demo with some different settings for LM resolution along with three different variations.
1 - UV islands setup on a grid in the UV 0,1 space for lightmaps. (Choose a target resoluton, I'll touch on this below before setting up grid) 2 - UV islands that are not on the grid 3 - UV islands rotated differently and not aligned properly
The scene consists of a row of tunnels (Similar to yours from what I could tell, at least enough to make a point) that is white washed to visibly see the seams. Then directly behind is a tunnel with two variations of materials (Rock and Metal Surface).
I did this setup for variations 1 and 2 with LM resolutions of 64 and 256 to see the difference. I only did one row with variation 3 @ LM resolution 64.
In the World Settings I adjusted the Indirect Lighting Quality to 2 and the Indirect Lighting Smoothness to 0.6. If you set this back to defaults you can see the smoothing between the seams is more harsh.
To go back to setting up UVs on the grid.
First you need to find the target resolution you want your lightmaps to be. I usually target 64 and snap the grid in my modeling software that way because if I need to up the resolution since I've set it up on 64 as a power of two I can increase it (ie. 128, 256, etc) and it will always be on the grid.
As an example, if I need to find the grid spacing for 64 I would do the following: 1 / (62-2) = 0.161290323 Source: http://www.reddit.com/r/UE4Devs/comments/246whl/the_most_important_thing_about_lightmaps/
Here is another thread that I was involved with going over some tips and things with LMs: https://answers.unrealengine.com/questions/92819/lightmap-uv-alignment.html
Here is my grid alignment/snapping for my UV. I've marked the hard edges as an idication for the four outside point. These need to be on a grid line. These are the hard edges of my mesh. The ones in the middle do not. The reason for this is since we're targeting a lightmap resolution of 64 we want these hard edges to be on a grid line because this will give us a hard shadow there. If the space were to fall between the edges of two grid points it would be considered shadowed and not hard. You can see this as edivident in the flatmapped UVs in the demo scene.
I know this is a lot of information, but for the most part take a look at the demo scene (built with 4.5) and see if this helps any. I've included the three FBXs that are in the scene as well.
Can you post a screen shot of your LM UV or if your still having problems the asset (FBX) in question (if you dont want to post publicy you can send via the forums in a private message) and I can take a look to help out.
Let me know! :)
answered Nov 20 '14 at 10:29 PM
Tim Hobson ♦♦ STAFF
It's possible to stop light bleed. I will, however, need more information on your setup though.
This should be enough to get me started in helping you understand how to resolve the bleed.
answered Nov 19 '14 at 11:06 PM
Tim Hobson ♦♦ STAFF
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