Lightmass: multi-bounced sky lighting

ldo · March 5, 2018, 5:31pm

In my scene I deleted all invisible boxes faces, attached visible ones and welded point, so it is no overlapping with the walls too. I tried with very little chamfer (1cm), it look even worse.
Below, 2048 lightmap resolution for all objects.

anonymous_user_f26c856c1 · March 5, 2018, 5:40pm

Oh cool! I’ve kept all the faces but excluded the invisible ones from the lightmap uv…
But if I understand you well: the “cubies” are one connected mesh? …not separate pieces? …I’d say you would have to have a huge lightmap with proper padding to get a nice bake… in mine all meshes are separate (even walls made up from 4 pices)… and in the render I posted they had 512 ligthmap resolution/piece!
…chamfering never worked for me! :S

anonymous_user_f26c856c1 · March 5, 2018, 11:40pm

Almost forgot! :S
https://drive.google.com/file/d/1NWGT6RE2wrhscWMDFAv0p-8gJl_uG5q-/view?usp=sharing

It’s scene for testing… a few of the upper walls in the corner are lightmapped “experimentally”! …well leaving all the uvs without padding was also some sort of!

ldo · March 6, 2018, 10:35pm

Thanks for sharing.
I can’t see on your pictures, but after backing light of your scene I am getting quite visible light gradient on walls and bottom. I don’t know why, but my color gamma is much more warmer then yours.
All I did is opened your scene in 4.19 p6, assigned skylight HDR image and pressed bake. Hmmm…
And one more thing, when I changed Static Level Scale from 0.1 (which is very expensive) to 0.4 I got A LOT of light artefacts…

anonymous_user_f26c856c1 · March 6, 2018, 11:04pm

No worries!
That’s weird! I had HDRI skylight in the scene (nothing else! ;)) I din’t know what happened to it… /I see it’s “disconnected”! :S
It was built in 4.19.5… are you using a different tonemapper than the default?
…with 0.4 you should get LESS artifacts! :S …I’ll do another bake with the new update and I’ll post the result tomorrow!

anonymous_user_f26c856c1 · March 6, 2018, 11:13pm

Ok I know the color differences! :S My bad: it had a different HDRI!! :S SORRY!! :S
http://hdri-skies.com/shop/hdri-sky-293/

anonymous_user_f44f0dfd · March 7, 2018, 1:56am

Hello Masters…
sorry for my english… …I, an ordinary mortal, please help… any progress in solving problems with this artefacts??? :((( Its not problem with my lightmap!! Thanx for anything…

anonymous_user_f26c856c1 · March 7, 2018, 3:47am

Hi Monkey!

I ain’t no master just another mortal!
I’d guess those upper meshes are intersecting/face overlapping with the ceiling/wall… and they are in-between lightmap texels and it can’t visualize the correct information…
If this is the case you can

raise lightmap resolution for both ceiling/wall till lightmap density gets so small that they won’t be noticable
in ceiling/wall “cut out” those overlapping faces from the lightmap + pixel/grid snap it
Try to move those upper meshes a little bit to find a perfect texel match
The table mesh’s uv map is not snapped properly or doesn’t have enough padding…

Very nice scene!!

ldo · March 7, 2018, 2:36pm

Hi Makigirl,
I tried your scene with the new hdri and increased Static Lighting Level Scale from 0.1 to 0.4 and it still looks quite good, except of Some parts of the walls, see on screenshot.
Red issue - maybe because of only one front face on UV with very little padding.
Yellow issue is clear - different meshes makes this strange different shading issue… Hm… On SLLS 0.1 it is almost disappear.

anonymous_user_f26c856c1 · March 7, 2018, 3:22pm

Sorry again about the wrong HDRI!! :S
The yellow is because of the modular pieces… if you go with 0.6 on smoothness those should disappear!
The red… I’ve seen those on medium build but disappeared on production…
To be honest I think this scene is “lucky” and shouldn’t be taken as an example! No paddings on lightmaps!! Never worked for me before!

ldo · March 7, 2018, 4:06pm

On the screenshot posted above, it was build with smoothness on 0,6 and build quality on Production. If I am correct the both problems were completely resolved with SLLS on 0,1… But it takes quite a while to bake even this simple scene. But you’re right, starting with 4.19.p5 it is getting way much better in term of lightmapping control!

anonymous_user_f26c856c1 · March 7, 2018, 4:18pm

Well I set really high lightmap resolution for all the meshes so yeah it takes a while to bake!
I was so happy with the result I haven’t even tried to set them lower… if I’ll have time!

anonymous_user_f44f0dfd · March 7, 2018, 8:34pm

Hi!
…did you find any solution?

samfisher288 · March 12, 2018, 7:14pm

Hello Guys! Can i help lightmass settings! I used build 4.18.3. I have problem skylight hdri settings and very bad shadows! Only skylight cube map hdri hdri shadow is very bad Why ? lightmassbase.ini settings better is a shadows qualitiy or ? THX

anonymous_user_f26c856c1 · March 13, 2018, 3:27pm

Hi!

First of all your lighting scale is way too low!! I would never go below 0.1… I think you won’t get those details anyway because of your lightmap resolution and it will raise your build time by a lot…
Do you have portals at your openings? …and lightmass importance volume?
First I thought (without seeing your settings) that it’s a compression issue but I see you’ve turned it off already… you can also try to clear cache in swarm agent…

anonymous_user_b87999901 · May 12, 2018, 1:01pm

hi , the file you uploaded is not here, you could share it again, thanks

anonymous_user_f26c856c1 · May 14, 2018, 2:26pm

Sorry, I don’t have the file anymore…

anonymous_user_7c28dc5d · June 5, 2018, 8:32am

Hi, few months passed and I wonder if anyone or Epic has any new or alternative solution for the black edges so far (other than Makagirland ParsoDeathworkaround above)?

Bladerskb · June 6, 2018, 10:19pm

can you reupload this?

Gnorkie · June 11, 2018, 2:43pm

The “most working” workaround for me was to cut the polygons where they were meeting corners and put the hidden polygons into separate UV islands.