Hi, First here’s my level:
Everything is made of modular assets. And here’s the lightmap density of my level:
In order to reduce drawcalls, i’m trying to merge those meshes but here’s the lightmap density of the merged mesh:
As you can see, some parts have no density at all. The blue lines on the walls are stretched ligthmaps
But other parts have no lightmap resolution:
Hey Haoris,
At first glance it looks like you are running into this issue: Unreal Engine Issues and Bug Tracker (UE-41161)
At the moment this is intended behavior because if you maintain UVs of a merged actor they will overlap which will generate incorrect results for baked lighting. I do have a workaround if you wish to maintain this listed in public notes.
Basically only lightmap UVs are wiped so you need to assign lightmap index to a throw away channel.
We understand the value of maintaining UVs of merged actors and as far as I know we are looking into solutions for this problem. However, for the time being this is intended behavior.
I hope that helps!
Ed
Well, what you see in the image 3 is one single mesh.
What I don’t understand is why some parts of this has UV map and some other don’t.
Why do the pillars have lost their UV maps while walls didn’t?
Ue4 is pretty good at batching. Are you running into draw issues? Is this for mobile?
If you aren’t running into low framerate/high ms count, then you shouldn’t need to worry about it at the moment, barring it being set up for mobile.
Best of luck!
We haven’t done extensive testing on this. I haven’t reproduced this with our in-house content. This may be potentially content specific with how you have your meshes setup.
If you would like you could send me a small sample project with just the bugged meshes (before they are merged) and I can look into this. If you want privacy you can PM me here:
https://forums.unrealengine.com/member.php?484739-Ed-Burgess
