Lets make Lightmass EPIC (and understandable)

[halftones]

Hi ZacD, yes lightmap compression is off already, thanks! I'll search for that forum post

[Luckyfox]

Thank you for this thread, so much info to digest.
I have a problem though when I try to bake one of test scenes posted here: the Swarm Agent log shows something not very promising:

21:32:42: Couldn't gather the requested number of indirect photon paths! 0 gathered
21:32:42: EmitDirectPhotons complete, 0.000 million photons emitted in 0.1 seconds
21:32:42: EmitIndirectPhotons complete, 0.000 million photons emitted in 0.1 seconds
21:32:42: Marking Irradiance Photons complete, 0.000 million photons marked in 0.1 seconds

Sometimes it bakes and sometimes not and it just fails.
Does anyone know why it can happen?
4.12.5, gtx 680, 64gb ram

[egalegal]

Maybe a little bit offtopic, but why is lightmass rendering not executed on the GPU?? I thought GPUs are designed to perform graphical tasks like GI? Coming from Blender and even there you render on the GPU (and by the way much faster than on a CPU)

[ZacD]

Epic is well aware of GPU rendering as an option for lighmass, but there's some likely issues

1. Epic would have to re-write lightmass from scratch.
2. Results might not be as high quality (people already complain a lot about lightmass and seams).
3. You probably couldn't work in the editor while baking using the GPU.
4. The editor/GPU lightmass wouldn't scale well for lower end machines.

They might get around to it eventually, but if reasonable settings you can get a decent lighmass bake pretty quick. The Lightroom: Interior Day Light by Koola example scene bakes in about 5 minutes for me.

[Casandez]

links broken

Scene: https://mega.nz/#!rtQ3XLzT!7BR5v95YW...uFEJHDxljR_jqM

File BaseLightmass.ini: https://mega.nz/#!n5xGSLiT!ZmOMwf69N...Krv6KTkfp9WfJU



links broken, where i can get it?

thanks.

[jldevoy]

I wish they'd add more control of portals, more along the line of mental ray/arnold .

[hellozhishi]

Scene: https://mega.nz/#!rtQ3XLzT!7BR5v95YW...uFEJHDxljR_jqM

File BaseLightmass.ini: https://mega.nz/#!n5xGSLiT!ZmOMwf69N...Krv6KTkfp9WfJU



links broken, where i can get it?

thanks.

same question [MENTION=37103]Raghu[/MENTION]

[PDantas]

Hi guys! Been following this thread for a while, and got amazing insights here on how to work the lightmass.
Nonetheless my adition is not so magnanimous.

I'm having some blotches showing up after the bake and I can't figure out why. Increased lightmap resolution, verified UV's, baked in production, but I'm still stuck with same problem.

Everything else seems to be ok (light is too strong and burning quite a lot)!

It's strange cause I already used this model in previous works and never had this problem. Also the wall should be complanar and the shadow much smaller.



Is this due to indirect shadow?

[heartlessphil]

Could be overlapping uv's or a too low memory streaming pool. Do you get flickering shadows on that couch when you move around the scene?

[PDantas]

No, no flickering. And I verified the uv's and ther all correct. I adjusted the light and the result improved a little with the shadows getting softer. It seems to have improved.

Thanks nonetheless

[Farshid]

links broken, where i can get it?

thanks.

GoogleDrive
https://docs.google.com/uc?id=0B3wYK...xport=download

Dropbox
https://www.dropbox.com/s/0ljra2l3h0...dNaji.zip?dl=0

Microsoft OneDrive
https://1drv.ms/u/s!Ar7INFDcXdscgnWMCXW4AKFmf0Sa

Mediafire
http://www.mediafire.com/download/9x...arshidNaji.zip

4shared
http://www.4shared.com/zip/8ARByBcice/FarshidNaji.html

Uptobox
http://uptobox.com/s6m3icy2uknu

[Casandez]

thanks so much

[S-Dot]

Hi guys! Been following this thread for a while, and got amazing insights here on how to work the lightmass.
Nonetheless my adition is not so magnanimous.

I'm having some blotches showing up after the bake and I can't figure out why. Increased lightmap resolution, verified UV's, baked in production, but I'm still stuck with same problem.

Everything else seems to be ok (light is too strong and burning quite a lot)!

It's strange cause I already used this model in previous works and never had this problem. Also the wall should be complanar and the shadow much smaller.

[ATTACH=CONFIG]109930[/ATTACH]

Is this due to indirect shadow?

I'm guessing a bit here but if the gap is too big and the shadow from the gap over the door is bleeding around to the wall then it's most likely that you haven't separated the polygons inside the gap from the wall polygons. Maybe this image helps (I made it a while ago for unreal 3 but it is still valid)


For the couches: We always have these problems with old high poly objects. It is really hard to make a good lightmap for a high poly object. Best is often to just bake a new low poly object off the high poly old vray asset.

Despite the general problems it might just be that your lightmap resolution is too low for the couch and the shadow is bleeding from one uv chart to another. (a too low lightmap resolution could also be caused by texture streaming issues but the scene seems to be small and not having any streaming issues.) Unreal is pretty good in rearranging the lightmap uv's. You could try to reshuffle the uv charts in the mesh browser (built settings just after the material section). Use 1 as source and target uv channel, set the minimum resolution to maybe 128 or 256 and hit "apply". Then make sure you increase the lightmap resolution further down in the static mesh settings as well.

[PDantas]

Thank u [MENTION=273030]S-Dot[/MENTION]!

Appreciate the feedback and the input.
I tried what you said regarding the reshuffling the uv charts and apparently something worked.

[NasteX]

Hello! I am curious about the indirect contact shadows in UE4. How do I make them more darker? Is it the combination of the intensities between the skylight and directional light (skylight is more intense than the direct light) or less indirect lightning from the directional light so the skylight can introduce those nice dark contact shadows etc. I tried a lot tests and I definitely get some contact shadows but I never manage to get them darker. I see alot from you guys that have nice dark contact shadows. What is the magic?