I have this apartment scene and as you can see in the attached pictures, there is this non existing light lighting the corners of the walls.
Lighting setup:
one skylight with intensity of 5 cd/m.sq and one area light in the interior for lighting the bathroom
Lightmass settings:
Static lighting level scale = 0.5
Number of indirect lighting bounces = 20
Number of skylight bounces = 12
Indirect lighting quality = 2
Indirect lighting smoothness = 0.7
I have read various thread about light leaking and even tried different solutions like fixing lightmaps by manaully doing them, padding them and snapping to the texel grid, some said snap the vertices of geometry and dont intersect. some said intersect the geometry to make sure mesh is watertight.
I tried adding a big box encompassing all the walls of the apartment except the window and intersected the surrounding box with the walls slightly so to make sure that window is the only opening in the apartment but it didnt do anything.
I thought the issue could be with the geometry (normals), so I tried to unlock normals in maya, tried harden edge to the walls but still nothing happened.
I tried changing the ue4 import options for normals from compute normals to import normals and tangents but still nothing happened.
Any clue what it could be?
I have other lighting scenarios with indoor artificial lighting only without any skylight and I still see those artifact. Maybe it really is geometry issue? if it is, I cant pinpoint what it exactly is and how to fix it.
I’ve never used are lights but…
I think right now the main problem is your indirect quality! 2 is waaay too low for an archviz scene!! Try 4 and higher (8!!) and you’ll see massive differences!! /and building time!!
You can go lower with scale if you want more detail /and if you have high enough lightmap resolution!!/.
I wouldn’t go higher than 10 with any of the bounces /they get kind of random + can cause strange results/.
Understood. Thank you for responding!
I will try increasing the Indirect lighting quality and will decrease the unnecessary bounces and will update after building the lighting
So I tried building with the updated lightmass settings as follow:
static lighting level = 0.6
indirect bounces = 8
skylight bounces = 8
Indirect lighting quality = 6
the bake looks much cleaner from before but still it has those bright white corners which it shoudnt have.
Could it be the geometry issue? I tried subdividing the mesh in maya so that the normals get updated and then again tried to unlock normals in maya and then did the fbx export from it following the fbx guide in the unreal docs. I still get the errors while importing like degenerate tangent bases and having zero binormals but I always had those errors in almost all the projects but they worked out to be fine.
This is the only project where I cannot pin point the problem.
I am attaching the screenshots of the new bake. Thanks in advance!
I have made an external box so that no light can pass through the walls so its like a double protection. also even when I bake lighting with only interior lights, I still get the same issue at the same places but its not much visible as everything is pretty bright. so my guess is that something can be wrong with the geometry. But my question is, what could be wrong as it is fairly simple box shapes…
And one more thing is that when I build using medium quality, I almost dont see those bright spots. Maybe because the quality is not good enough to bring out the details in those spots. could it be something only with high and production quality?
I think it’s unrelated but it’s better to corner/edge snap walls to avoid those dark edge lines… /or include ONLY the visible polygons in your lightmap uv!/
Are you using reflection capture(s)? …maybe there are just wrong reflections and just needs to be updated?
If you could try one thing: on your problematic meshes could you turn off “use mikktspace…” in properties and try to rebuild?
yeah I searched for the solution for those black edges as well and I have my walls snapped together. but they are still there. better than what a mess I had before but still there. As I am on it I will also remove uvs for non visible polys to see if it does something. I will update after building the lighting again.
Thanks for your quick response!
Hey! I tried what you suggested. I removed the invisible faces form the lightmap uvs and in the fbx import dialog box in ue4, I put the normal import method to “import normals and tangents” so it doesnt have to use mikktspace.
I rebuilt the lighting with pprevious setting but the result is still the same. I still get the bright corners.
one thing to note is with other lighting scenarios, with skylight and indoor spotlights, I still get the bright corners but when I build with only directional light with skylight intensity of 0, I dont get the bright light in the corners.
Do you have lower hemisphere turned on?
Are you updating your reflection capture(s)? …maybe it’s coming from those… Have you checked that view if it’s accurate and not getting info from outside of the room?
I have the “lower hemisphere is solid color” checked on so that the lower hemisphere is black. I also removed all the reflection capture actors from the scene before baking so that theres no issue of reflections. but unfortunately the results are same.
I also tried covering the part of hdri where I dont need the light emitting with solid black color and now I only had the hdri part whoch was facing the window side. But still there is no change, I still get the bright spots.
Not sure if my setup is corrupted or it is a ue4 skylight bug
I’m not sure if it’s a good idea not to use reflection captures… :S They do help with the correct lighting!!
…you’re not the only one who’s doing archviz scene so I think there would be a lot more posts about this if it was a bug…
Have you tried different HDRIs? …like a plain grey one…?
I tried with and without relfection captures but the same result. And yeah you are right if it was a bug it would be in light already. I didnt try different hdri. btw I am also increasing the maximum texture size after I import the hdri in the texture editor window. and I also set the noMipmapa setting.
I will try using different simpler hdri and will tell you.
Thanks for all the help!
No worries, I hope it will work!!
A few more questions, it looks like it’s the sky…
Is it on Stationary or Static? …any differences if you change?
Also: have you checked different views if you could catch what causing the problem? /check the sample view if the spheres show the lighting problem…/
Reflection capture: if you place one fresh and start to move in the scene: do you see lighting differences at the problematic areas?
1 more idea: if you could upload the scene somewhere I could take a look at it in a few hours…
