Lets make Lightmass EPIC (and understandable)

[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.

[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.

[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)

[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

[halftones]

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

[ZacD]

Well, 1024 is 16x more pixels than 256. Some banding in dark places is normal, make sure light map compression is turned off, if it isn't already. There's a forum post about how to deal with light mapping curtains, I'll have to look for it, there's some tricks to it.

[halftones]

Hi Guys,

I'm studying UE4 right now following all what I read in the forum and the documentation, I'm kinda stuck with the "lightmass or shadow" problem of mine.

Here's a screen shot of a test scene

Shadow or lightmass detail is not good in the curtain..


light map res for the curtain and all the walls are at 1024, I tried earlier with the curtain at 256 with a build time at 5mins, and the attached one with the 1024 which ended at 30mins T_T
baselightmass.ini are at default and the lightmass settings are .25 / 8 / 4 / 1.1

How can I fix the shadow issue? And also at the back wall I'm having a bit of grey scale banding, is that normal with the lightmass current settings and a dim lighting?


Thanks! You guys rock! \m/

[devel.bmad]

Confirmed.

only NumIndirectPhotonsScale=4 seems to solve this issue, even if the box is moved/scaled.

[MENTION=5618]koola[/MENTION] and [MENTION=206489]Ptyx[/MENTION]:

I happen to see this kind of problem many times, for example when there are pieces of forniture close to a wall. The back of the object seems to reflect or emit light, often with strange colours coming from nearby objects.

Is there any sort of cache for lightmass that can be cleaned up? Sometimes this problem seems to go away or come back even just building light multiple times.

[devel.bmad]

Does anyone have any experience with the mac/OS X version using lightmass portals? I can't seem to get them to work.

Thanks,

They are working for me, what is your issue? Be sure to cover all the places where the light gets in, or there may be some artefacts.

[worldlearner0411]

I have AO turned off in the lightmass settings, is this what you mean?

[ZacD]

Do you have ambient occlusion turned on in the light map settings?

[worldlearner0411]

Hi guys!!!

I have been struggling with an issue for a couple days now, and if there is anyone that has an answer to my problem I'm begging you to tell me No matter what I do I keep getting black artifacts at the bottom of my boxes (see below)



I'm building at production settings

Scale = 0.2
Indirect Bounces = 30
Quality = 2.0
Smoothing = 1

I'm not currently using portals and I'm using 4.11

My lightmaps are solid. The roof, floor and each wall are all separate lightmaps. The boxes are set to 512 as well. I assure you I did not start off with a 512 lightmap for a box lol

I have tested the whole scene with 2k lightmaps. I have tried about every setting I can think of. I have tried positioning the boxes below, above and aligned with the floor. When I turn the lightmaps up the black lines become even more noticeable.

Thanks for any help

[David Boura]

I've finally finished reading all this thread, it took me around 4 hours, but that was worth it really!

Thanks to everyone who has constructively contributed.

[jazvec]

these are Engineering Sample cpus. same thing as retail with slightly lover clock. i have E5-2697 v4 for 600$ each. but i guess support could be problem with those.

[Raghu]

hi. i have a serious question. does unreal actually support dual xeons? everyone assumes it does. ive build a dual 18 core machine, 72 threads in total, set the swarm for 72 threads, but the baking works always only on one cpu. the other one is idling. an unreal is not the only software that hve a problem with this. can somebody here give me a final answer? thanks

I only posted the image to clear your doubts regarding the full support of Dual Xeons in UE4. I highly recommend that you post your problem on 'UE4 AnswerHub' there you will get the full technical support. Just wondering though, why your CPU name is like - Genuine Intel(R) 0000 @2.20 GHz. Normally it shows the CPU model name.