Lets make Lightmass EPIC (and understandable)

Robbie222: plane and spot

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Try the same scene with a lightmass portal and a pure white skylight (make sure Lower Hemisphere is Black is unchecked)

ZacD, SkyLight have only 1 bounce?

SkyLight+HDRI Only
Lightmass Portal

LMSize = 512
Lighting = 3:39:23 hours
Hemispheres = 16644=4096

You would not get nice results like that with 1 bounce. The amount of bounces is tweakable in your world settings -­ lightmass settings.

But 3h40 of light building for such a simple scene, your settings are off I think :stuck_out_tongue:

, nice results because the light is scattered and comes from two directions, but shadows are black. The amount of bounces in world settings is only for lamps and sun.

i want to get lightmaps without artifacts)

Roadmap:
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Old scene:

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With Portals:

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9 hours, what the hell lol! Looks good in theory but in practice it’s not viable. Imagine baking a complex scene like that. You’d need a renderfarm.

Do you use lightmass portals + a custom ini? both would probably increase build time exponentially!

I explore the extreme values)

can be reduced hemispheres scale \4 and get nice result.

Why “Lower Hemisphere is Black is unchecked”? Whenever i uncheck it, all scene is brighter and shadows are unrealistic. I think it damages realistic looking especially both interior and exterior scenes. What do you think?

Lower hemisphere unchecked can be good to simulate a light bounce when you use all dynamic (movable) lights, otherwise leave it checked. When you are using static lighting, lightmass will calculate all light bounces, there’s no reason to inject fake illumination coming from the ground imo. If it’s too dark, instead, raise the hdri intensity. Somewhere between 1-10 is usually good.

Hello guys,

i am trying to make a interior scene in unreal but it is not looking soo realistic, i would like if someone suggest me about its lighting.
And i would like if someone guide me about baselightmass.ini.

i am attaching the screenshots of my project.

Thanks in advance.:slight_smile:

Forget about lightmass.ini. You tweak that when you master all the basics. Unfortunately tweaking the ini doesn’t magically give good results, it only explode your render times.

You need to learn how to balance all your light sources. I usually start with only a hdr image (plain grey with a white spot to represent the sun) in the static skylight cubemap slot then I bake with medium-high settings. You’ll get nice soft shadows. After that you can add a sun if you need it. I tend to prefer the ‘‘studio’’ light setup or overcast day light setup. Concerning fake lights, lamps, tracks lights, etc, I prefer to set them to dynamic because it won’t produce any splotches and artifacts.

Good settings :
-Use portals in openings. You can also add them in doorways inside the house.
-Play with static lighting scale value. Below 1.0 if you want indirect soft shadows. I tend to use .2 to .4
-Indirect lighting quality around 2-3 is usually enough if you have good lightmaps. You can use 6+ for the final production shot.

At the end I’ll tweak the post process volume and/or finish in photoshop.

Does anyone have any suggestions for huge open floor plans in regards to lightmaps and resolution? Specifically, what is the best practice when dealing with a large floor that will receive direct shadows. Should I break apart the floor into multiple models and assign individual light maps & resolutions? I’ve had some trouble with shadow bleeding from panel to panel in the past when breaking apart floors and I’m hoping someone can shed some light on this. I’ve attached an image of my current projects floor for reference (this model is straight from Revit so I still need to optimize the geometry)

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Ideally you would separate it in multiple parts. If you need to make an image of the whole thing you’ll see differences in lighting on each mesh but if you carefully choose the angle for each image, you could get away with it. Let’s say you have a camera at knee-height, you’re not going to notice the differences that much. If you have a wide angle shot from high ground then you’ll see it. You can also use your ground material to hide most of the effect. If you have large concrete tiles, then divide the meshes into large tiles that correspond to the concrete tiles material. It could even look better than a uniform looking huge surface. It ‘‘simulate’’ imperfections to a certain extent haha!

Epic should add something like when you group static meshes together (CTRL+G in editor),the group would be baked on the same cpu thread instead of sending each static mesh to random threads. Sounds too simple, there must be a limitation that I’m not aware off!

You can try to hide seams in natural ways, along a seam or edge of a texture like tiling wood or concrete. Rugs, furniture, or transition strips work too. If you do not need super detailed shadows, you can get away with some pretty low resolution lightmaps.

I figured as much, it’s a terrazzo floor that I’ve now broken into several sections. Unfortunately it’s an open lobby set to be displayed in VR so I can’t all of the seams. I would love to see Epic address issues like this – I’m in the architecture world so it’s rare I can create modular sections for a floor. Everything is custom and owners are picky…
Thanks for your input guys :slight_smile:

Guys any new suggestions on lightmass tweaking and settings on UE 4.14 ?

I want to translate this thread into Chinese. I will post the address after finishing the work.

How would you guys go about lighting an interior office scene ?

The problem I encounter right now is that point lights spread the light around as a perfect sphere, resulting in very obvious light and dark spherical area’s in the scene.
I want to somehow achief a more uniformly lit area.
In an office environment most lights are long fluorescent lamps. Usually enclosed in such a way to create a large light, creating an evenly lit area without hard shadows.

Curious if someone has some ideas or examples for stuff like this. I’ve seen some very done scene but they always seem small and mostly lit by the sun as main light source.

All you have to do is change the Source Radius and Length on a point light.