UDK - Lightmass bouncing issues.

SgtFrenzy

Hi Guys and Girls,

I was hoping someone could help me with getting lightmass bouncing in my UDK scene. I apologise if there as simple fundamental mistakes I'm making as this is my first UDK scene.

I've got a directional light inside a lightmass that also encompasses the room I'm trying to light.

Light bounces for the world are on and set to 5, but as you can see there's no light bouncing going on.



Any help would be great!

James Ordner

What is your environment color/intensity? Also try baking your lighting without windows and/or turn ambient occlusion off in the Lightmass settings. Make sure 'Use Global Illumination' is checked as well.

osman

Every light, material, bsp and static mesh has a variable called Diffuse Boost. Turn that up a notch to see the effects of light bouncing. ( one global value for it is in WorldSettings -> Lightmass )

Also, what is the scale of your world compared to unreal tournament?

SgtFrenzy

Thanks guys, the scale is about half UT (everything was created to real world sizes in max, but it's all strangely tiny when you play the map)

I'll try your suggestions once I'm home from work and post the results.

osman

Alright, if it's half size of UT then you should change the world-scale value to 0.5 in the worldsettings -> lightmass

SgtFrenzy

Ah, it's looking like the issue was the ambient occlusion settings.

I've set the world scale to 0.5 and tweaked the values and I now have



Obviously the lighting is going to need a lot more work (and if you have any advice I'd certainly appreciate it), but at least I can see what I'm doing now.

Thanks!

m1neh

Hey, having almost exactly the same issue, but editing with world scale (if you mean Static Lighting Level Scale in World Properties -> Lightmass?) but to no avail. No idea why my Dominant Directional isn't bouncing. Don't mean to hijack your thread, but thought you, or someone else might have an idea!

James Ordner

@ m1neh, change your environment color to something light bluish, to simulate indirect light from the sky. I'm not sure why the sunlight isn't bouncing, maybe others have some idea.

@ SgtFrenzy, don't forget spotlights and pointlights. You won't be able to light the whole room with a single directional light effectively. Spotlights are very effective with lighting walls, corners, etc. Nothing to extreme, but subtle spotlights can make a world of difference if you think about where to place them.

m1neh

@ James, I'm aware that lighting the environment colour would lighten the darkest areas of the level, but that's pretty much the same as using a skylight. Would rather keep away from relatively outdated lighting techniques, but I thank you for the suggestion.

James Ordner

Using environmental lighting is different from using a skylight, and not outdated. It is realistic for outdoor scenes as well. In real life, you have two primary light sources in outdoor scenes, the orange/red directional light from the sun, and the blue color from the sky. Sunlight appears white in most cases because the orange sun and the blue sky balance out. It's also why shadows sometimes appear blue, as there is no orange sunlight to balance out the blue.

Environment lighting in UDK simulates this blue lighting from the sky, and will not illuminate areas that ambient lighting cannot reach. This is unlike a UDK skylight, which lights the whole scene evenly, regardless of whether or not a surface would normally recieve light from the sky.

Long story short, it is not outdated to use environment lighting, and it is more realistic to do so. Look at the example midday scene included with UDK for reference. It uses environmental lighting, not a skylight.

m1neh

Interesting, I will deffo look into this. It would, however, still be great to get light bouncing!

m1neh

Tried editing the environment colour (even up to pure white) with absolutely no difference to the scene whatsoever!

SgtFrenzy

The lighting in my scene now looks like this



Remaining on the list of things I need to work out / implement.

Reflections on the TV screen.
Better Glass material on window and bottles (fixed translucent materials in general).
Improve the light rays.

Anything else that would be suggested?

James Ordner

I would add something to that back corner, it looks a little plain, like a broken chair or something. Also, not sure if you know or not, but the best way to create actual light beams is to use static meshes. Check out this article for a more in-depth look.

SgtFrenzy

Thanks James, I'll get on that as my next step.

Ark

The environment still looks far too dark considering there's two decently sized windows with a skybox suggesting a strong ambient sky and halation on the windows.

James Ordner wrote: »

Using environmental lighting is different from using a skylight, and not outdated. It is realistic for outdoor scenes as well. In real life, you have two primary light sources in outdoor scenes, the orange/red directional light from the sun, and the blue color from the sky. Sunlight appears white in most cases because the orange sun and the blue sky balance out. It's also why shadows sometimes appear blue, as there is no orange sunlight to balance out the blue.

Shadows are blue because the ambient light from the sky is illuminating them, even more prominent on clear skies when there's no clouds diffusing the the blue light.
Most people just use blue shadows because it offers good contrast being complimentary colours. Doing a overcast day with blue shadows where the sky is full of dark clouds would just look wrong.

Sunlight ranges from multiple colours through the day, normally reddish/orange in the morning when the sun is low, through to a yellow in the day, sometime more a desaturated yellow, then it reverses and goes back reddish/orange as the sun starts to set. Colours also vary depending on the time of the year.

Reason most sunlight looks white is because of white balance. Your eyes play tricks on you. Best way to see this is look a house lit up at night from outside, it'll look orange, go inside and it'll appear more desaturated.