Lets make Lightmass EPIC (and understandable)

[MSL]

If you take good care while modelling, then you don't need to tweak ini values in 4.11. But, in very rare case for very large environments to remove few artifacts you may have to fiddle with ini values

With regard to changing values in ini, Yes, you need to change the corresponding settings i.e., if you are using Medium quality for light building, you need to change values under Medium settings in ini

[VirtualLilies]

I've been reading this thread for the last couple hours and what's boggling my mind is whether we still should use modified *.ini values or not (while using 4.11).

And just to clarify, when I'm changing the values should I refer to a specific setting (medium/high etc) or should I change any global settings ? The only thing I've been playing with was (...)HemisphereScale set to 256 for a particular quality setting (in my case medium). I'd appreciate anyone enlightening me on this topic.

[heartlessphil]

It's because you have no materials on your brushes Stan!!! And even with a material, the resolution of the lightmap of a brush (vs static mesh) cannot be good enough for detailed shadows.

[Stan Brusse]

yeah really weird,

Any help would be greatly appreciated!

Stan

[heartlessphil]

I'm on 4.11 ps4 and my scenes are working fine. I'll try to check it out later today.

That's really the most basic scene ever you have there hehe, you must have missed a setting or something.

[Stan Brusse]

Hi,
Thanks for getting back to me.

I wonder if there isn't a issue with the 4.11 P4 as I can't even get shadow with a simple scene :

two boxes and a skylight :



I used the HDRI provided by the starer kit.

scene :
https://drive.google.com/file/d/0B6T...ew?usp=sharing

Any ideas?

Thanks
Stan

[heartlessphil]

Stan, your ground mesh and floor mesh are one sided planes. In unreal, the backface of any polygon is culled so that means light will pass through it. Make sure your walls/floors/ceillings have some thickness. so basically in your scene there's nothing that block light from coming underneath. This is the view you get when you look under your house.



Other things :

-Your hdri is VERY bright, lower your skylight intensity or use the epic default hdri, it's probably more balanced.
-It's just better to use a static skylight instead of a stationary one.
-I don't think you need a portal in each window, 1 per room should be fine. They increase build time too.
-Increase the size of the portals a bit like this :



Good luck.

[CGMen]

Hi guys,
I'm trying a pretty easy and fresh new scene.
Dont' know what's wrong but I can't get sharp shadows, it just doesn't look right.

Light maps 64 - Render time 6 sec :


Light maps 1024 - Render time 16 min :


Here is the project:
https://drive.google.com/file/d/0B6T...ew?usp=sharing

UE 4.11 Preview 4

Any ideas?
Stan

Hello. Sory for my english. I think you need just place in to the scene Direct Light and turning of some angle. He is emulated Sun light and you get sharp shadows.

[Stan Brusse]

Hi guys,
I'm trying a pretty easy and fresh new scene.
Dont' know what's wrong but I can't get sharp shadows, it just doesn't look right.

Light maps 64 - Render time 6 sec :


Light maps 1024 - Render time 16 min :


Here is the project:
https://drive.google.com/file/d/0B6T...ew?usp=sharing

UE 4.11 Preview 4

Any ideas?
Stan

[SQUAREBYTES_GmbH]

Just some tests with only `skylight`

I have used 0.15 in `static lighting level scale` and `NumHemisphereSamples=128`

I like the light quality in your scene. Awesome!!

Do you use a hdri map for the skylight?

Do you changed something else in the the baselightmass.ini except the NumHemisphereSamples?

And what about the World Settings in the Editor?

[RI3DVIZ]

With portals, you can get away with lower lightmass settings, and not messing with the ini as much. I would still use them for every window, and try lowering Indirect Lighting quality to speed up render times. It should be in the middle of the window, and take up the entire length of the window, and be used for every window where you want higher quality lighting and shadows inside. It should be slightly larger than the window, and can be used on big windows.

Good to know!

[ZacD]

With portals, you can get away with lower lightmass settings, and not messing with the ini as much. I would still use them for every window, and try lowering Indirect Lighting quality to speed up render times. It should be in the middle of the window, and take up the entire length of the window, and be used for every window where you want higher quality lighting and shadows inside. It should be slightly larger than the window, and can be used on big windows.

[SQUAREBYTES_GmbH]

@goergino

Can you tell us which settings do you have in editor and in the baselightmass.ini File?

Do you use a skylight and directional light?

Cheers
Marcel

[RI3DVIZ]

I think you probably only need portals if there are small windows and not enough light can get in - your main room probably doesn't need them.

[goergingo]

Before lightmass portal with 4.10 version, i created my workflow for lightmass settings (mixing koola's, rafareis and my methods) and i was starting to learn parameters effects to my scene. Everything was getting clear. But after lightmass portal i'm confused. I don't know, i have to change baselightmass.ini file.. And lightmass portals increase building times nearly 5-6 times in my scene. Should i use them for every windows? Lightmass portal is unnecessary if i have large windows? Or what about if i have non-regular windows? What will happen if i use them bigger than windows? Is there anything change will i use it inside of the windows or middle of the room? There are lots of questions like these.

I guess we need an extensive guide for lightmass portals and lightmass settings.. Like rafareis123's or koola's or raghu's experiments..

Here is my scene. I deleted landscape and foliage for shorter render times. Now my machine works on it with lightmass portal version.. without lightmass portals building takes 82 minutes (with 4.11 preview 3).

By the way front side of the villa.. you can see large windows of front side..


Here is non-regular windows..


Lightmass portal which is at the outside of the window..