Light build creates dark or black spots on geometry thats too close i assume

Light build creates dark or black spots on geometry thats too close i assume. I am wondering how i can fix this. See the screenshot… 1 screenshot shows a plant flat geometry next to a wall… the other is showing some roof tiles that sometimes get darkened… only answer i can come up with is geometry beign too close… Thid screenshot shows a wall that is darkened because it has objects on the other side of it.


Can you provide screenshots how to looks the UV1 Channels of these meshes?

Sure, but this problem also exists on foliage like grass or small bushes… any geometry that gets too close sometimes randomly gets some blackness… I tried placing stones as foliage along the terrain and 25% of them were completley black even though its all the same stone being placed.

Here are the screenshots. The temple gate i could probably up the lightmap resolution for better uv generation, but the rest should have no problem for sure.

That is ambient occlusion. Try going to world settings, lightmass, and uncheck use ambient occlusion if it is checked, and try building the lighting again.

If you still want ambient occlusion, reduce the max occlusion distance in world settings, lightmass.

Sorry thats not it. I do not have ambient occlusion enabled. AO im sure wouldnt blacken things that are facing the sky because of geometry that is behind it. Like that vine plant over the wall… that shoudlnt be completely black… if anything it would be completley white since there is nothing occluding it.

You could try increasing the light map resolution on the static meshes to 512 or 1024. You could also increase the number of indirect lighting bounces to ~30ish

that plant already has 64 resolution and its completely solid black… thats not going to help… and that glass wall… the rest of the wall is all 1 peice… and u can see the uv layout… its clearly taking geometry from the opposite side to influence the lighting… resolution isnt going to change that. Besides that wall is 256 resolution already…

The shadow on that wall is the exact size and position of a plant box on the other side of the wall that is near the wall. So as i said its taking lightring from the other side.

Are you using normal maps for static lighting?

If not, i’m all out of ideas.

If so, maybe the normal maps are fooling light mass into thinking that parts of the meshes (or the whole mesh) should be inside of nearby meshes. Try disabling that in project settings/rendering/lighting.

Yes am using normal maps for static lighting… not something i would want to disable since it would ruin lighting on normal maps. That would not be a solution. Aside from that… as i said before this happens on most objects in teh scene. I bet you can replicate the issue on your end if u make a very thin wall and put it nearly flush next to another big object on the other side of it and build the lighting. I have always experienced this issue in unreal engine 4… I am thinking there would be some sort of quality setting in lightmass for baking … maybe scale? i dont know, but right now im pretty much default settings on it and its doing this.

By the way how would a normal map of a wood texture on a flat surface have anything to do with a seperate model behind that body that is next to it…?

I attempted to replicate the issue using version 4.9.2 and could not. I’m assuming you have a light-mass importance volume in the scene, and your lighting build quality is set higher than preview.

And i used to have an issue with my normal maps having too high of a scale which would cause problems with static lighting. The low areas of the normal map wouldn’t get any light. I just figured disabling normal map static lighting would be a good way to see if the normal maps were causing issues.

Yes lightmass importance volume is there covering it and its on production… talkn 8 hour bake times :confused:

You sure you really did try it? lol… like did u make a really really thin wall and right next to it have a peice ofa box or something touching the other end or a slight distance from the other end…?

Can i see screenshots of all your lightmass related settings?
I would also like to see what yo uhave under build-> lighting info.

I dont think i ever touched any of that stuff, but just in case would be a huge help to see if we can rule that out.

Not sure if the wall is thin enough. I have one point light on each side of the wall. I made sure the cube is actually going inside of the wall.

I tried Multiple light-map resolutions on each mesh for testing purposes.

Also i changed the lighting bounces to 100 (was at 3 by default) and changed the smoothness from 1 to .5. Just keep that in mind

I’m all out of ideas. Hopefully someone with more light-mass experience will help you out.

Those black faces may be caused by flipped faces. What happens when you rotate those vines/mossy looking mesh 180degrees and then build the lights again(dont build the whole level - just get whe vines and a wall in an empty level to try it out.) If it builds the lightmaps normally then it is what i suggested.

i have my bounces at 3 and try to make the strucutre not touching the wall. just a very tiny amount away from the wall.

Only diff from yoru screen shots is my max occ difference is at 200 (default) instead of your 300.

Oh wait i know … part of the problem… This happens with ambient indirect lighting… not direct lighting… try setting up a scene with a sky light… and thats it… no directional light… no point lights… let that do the lighting only… and i bet you you will experience the problem.

Either have the models lit with skylight only, or just a light bounce only and i beleive the problem will manifest.

It’s been a year, but I hope I help someone who encountered the same problem.
I had the same artifact as on your second screenshot, those black polygons. In my case it turned out to be a static mesh problem: apparently, when I exported my quad mesh 3Ds Max did a bad job at triangulating, causing this artifact to appear randomly which is not seen when working in unlit mode.
In my case solution was to go back to 3D Max, convert editable poly to editable patch (to triangulate), then back to poly and for export. Basically, triangulating it myself before exporting solved the problem.