Lets make Lightmass EPIC (and understandable)

[Skykila]

Why Ue4 not use bc6h for lightmaps? Quality should increase significantly.

[heartlessphil]

Fantastic results from the portal lights.

I see the suggestion here is to use uncompressed lightmaps. Doing that I also found the quality higher, esp. when larger surfaces considered. But using a lof of 512/1024px maps, this seem to facilitate higher memory usage and thus lightmaps mip-mapping.
Which shouldn't be a problem with 12gb vram of Titan-X, but I couldn't stop this process by changing all .ini files I found on internet. No matter if I set shadow/lightmap mip-maping to 0/false, or rised value for memory pools, both in project and general folders, etc.. it would always mip-map those lightmaps,
which is just visually horrible. Anyone with similar issue got this solved ?

Like DanielW suggested, increase your memory streaming pool. I had the same problem on my gtx 980 4gb. I increased it to 4000 like that : r.streaming.poolsize 4000 (no more mip mapping like crazy)
Never had a problem after that and I usually have 4k textures and 2k lightmaps sometimes!

[heartlessphil]

Really really happy I managed to finish this scene in 59 mins (lighting build time)! I have contact shadows everywhere :-) The only settings I adjusted was the lighting level scale.
I took an evermotion model and optimized it for Unreal. I managed that lighting/shadow quality in 59 mins because of this thread and community. You guys rock!

Every tile has geometry, walls also have extruded parts, so it wasn't THAT easy to remove all lightmaps artifacts.

[tupikp]

Looks great Phil. However, I found that it's a bit odd that using smaller value for Static Lighting Level Scale can make the rendering more faster (as long as the other value in Lightmass kept to default, except Indirect Lighting Bounce). Especially because the tooltip says that using smaller values (less than 1) will increase build time greatly. I also found that using 0.4 gives better shadows and faster rendering time than value of 1.

[heartlessphil]

Yes it will increase the build time but compared to the other settings, it's really not that bad. I left indirect lighting quality to 1, bounces to 10, smoothness to 1 and it's the defaut baselightmass.ini. I really only used a scale of .4, uncompressed lightmaps. :-) My previous version took 16 hours and looked worse with the other settings cranked up. This scene lighting is simple tho, just a skylight with Epic's HRDI.

Also, by leaving the rest of the settings to default, I was able to raise the resolution of my lightmaps to 1024 to clear all artifacts, something impossible in my previous attempt that took 16 hours with 256x256 lightmaps :-S

[Enter Reality]

@heartlessphil: is this Production lighting or less? If you're able to achieve this lighting in 1 hours at Production level you won the competition

[heartlessphil]

This is production lighting yes.

But it's a big outdoor (mostly) scene, no furniture and small objects that would need huge amount of detailed shadows!!!

[Enter Reality]

This is production lighting yes.

But it's a big outdoor (mostly) scene, no furniture and small objects that would need huge amount of detailed shadows!!!

Ok, now I'm curious to see the test using an interior scene...like the one uploaded by Raghu

Could you also post your system specs? just for comparison

[heartlessphil]

My 2 pc were used to build the scene. Main is core i7 4970k+16gbram+gtx980, second pc is core i7 2600k+8gb ram+gtx 760ti

I will take an old interior/exterior scene I've made that took 10 hours to build and try to see how I can reduce the time while achieve similar quality. stay tuned.

[DanielW]

I have now checked in my Lightmass solver quality improvements:
A) Adds light portals - these solve static skylight quality in highly enclosed areas like the example
B) Fixed high IndirectLightingQuality settings disabling adaptive sampling - this improves static skylight quality
C) Fixed light leaks when using spotlights with StaticLightingLevelScale .1 - StaticLightingLevelScale is no longer applied to photon emission

These changes will be in 4.11 which will probably be in about 4 months.

So to wrap up Raghu's original post

1. How to remove the splotches in the area where there is no skylight hitting directly (Areas far from windows). As you can see in the above images there are so many splotches in gallery, despite having Indirect Lighting quality to = 10 and static Lighting Level scale = .1
2. Shadows become somewhat messy after a certain distance. How to make area shadows more clear and smooth.

This is addressed by A) + B)

3. Whenever we put spotlights to remove dark areas, it almost always gives the annoying problem of light leaks. Clearly evident in the above images.

This is addressed by C)

Sadly that's all the time I can spend on Lightmass atm, otherwise I would like to investigate some more complex scenes.

[heartlessphil]

Good work Daniel! Can't wait to test these features :-)

[DanielW]

Some comparisons

Raghu's original. Settings were StaticLightingLevelScale .1, IndirectLightingQuality 10, IndirectLightingSmoothness .75, no compression.


Improved solver quality + portals setup. Settings are StaticLightingLevelScale .2, IndirectLightingQuality 10, no compression, all others defaults. I probably should have turned down the smoothing a bit, notice how where the walls meet doesn't look quite right. Also, the exposure is different than Raghu's.


Raghu's original. Settings were StaticLightingLevelScale .1, IndirectLightingQuality 10, IndirectLightingSmoothness .75, no compression.


Improved solver quality + portals setup. Settings are StaticLightingLevelScale .2, IndirectLightingQuality 10, no compression, all others defaults.

[serriffe]

can't wait for 4.11

[tupikp]

Well... I might skip the 4.10 entirely... uh, can I? Or do I have to install 4.10 first before I can install 4.11?

[RI3DVIZ]

That looks good.