UDK - Blown out lighting when I add an extra light.

SaferDan

Hey guys,

I was wondering if you could help me, I have a couple of blue lights in my scene but as soon as I add another the lighting gets completely blown out. I have no idea why, its fine with two lights but not three!

This is what it looks like with Lightmass baked with two of the blue lights -



But when I add a third in the middle it does this </3 -



The only other lights I have in the scene is a dominant directional light and a skylight. I have a series of lights in another part of the level but I dont see why they would be affecting anything. I also have a lightmass importance volume.

Any help would be amazing, thank you.

Amatobahn

Check your light radius maybe? Also are you using static meshes or interp?

mekkael

Hi there, I have little (no) idea about UDK, more of a unity user here but is there a pixel light limit in UDK? I have seen something similar in unity when you use a vertex light instead of pixel lighting - sometimes this happens if you allow 2 pixel lights in the scene so adding another light would automatically change it to vertex lighting. the only other think i can think of is badly calculated light (photon ) bounces. Try moving the light and changing its settings and check the effect. By the way there seem to be some strange smoothing going on on the floor where the chair on the edge of the table is....

SaferDan

Hey! The radius of the lights just reaches the width of the windows and yeah it's all static meshes and everything is light mapped!

imbueFX

So when you add the 3rd light, are you trying to bake as well? Or is the screengrab above just adding the light without baking?

SaferDan

What I do is alt drag one of the other lights and position it. Then yeah bake light mass and it goes crazy!

imbueFX

Have you been tweaking the lightmass settings in the world properties? It seems like it could be a setting like diffuse boost, environment intensity, etc. that may be turned too high.

SaferDan

I just looked and they are all set to default. I actually remember copying everything into a new level just to see if it made a difference but it didn't </3

BB-88

What light types are you using?

SaferDan

The blue ones are just normal spotlights.

BB-88

So it's just three spotlights? are they overlapping? and does the problem persist if you change them to point lights?

Xendance

Try clearing the lightmass swarm cache. It solves oddities like this sometimes. Either by clearing the contenst of the swarmcache folder in your UDK/bin folder or inside the swarm coordinator utility that pops up when building lighting.

Jacky

Yeah, Swarm cahce causes weirdness like this sometimes. Just clear the cash in Swarm interface and bake again.

SaferDan

Ok so I have cleared the cache from the interface and via windows. That didnt fix it!

I changed them to point lights and got this -




Then I changed the radius so they were not overlapping and got this -




Also since clearing the cache over parts are going wrong!

I think my lightmass is super broken!

Xendance

Are those lights dominant lights? You can only have one dominant light affecting each primitive, otherwise it won't work properly.

SaferDan

No no I have one dominant which is the orange light outside!

SirCalalot

Try checking the properties of your meshes in the Static Mesh Editor (double click in the Content Browser) and seeing if the Lightmap Coordinate Index and Resolution values are set properly.
Remember that Index 1 in Unreal is Index 2 in Max.

It's a long shot, but these issues may be a problem with overlapping or dodgy lightmap UVs that aren't apparent until a light is hitting certain parts of the scene.

SaferDan

I have checked them all and everything seems fine!

I think I will try reimporting everything in that room and see if it fixes it!

Thanks everyone for the suggestions!

*EDIT*

I have found my problem! I took out all my lights and the importance volume, then put the importance volume back in and just the three blue lights. Light mass baked fine. Added three more lights on the other side. Fine. Added the dominant directional and bam horrible weird lighting!

I have no idea why my dominant directional is doing that though...

System

why are you using a dominant directional for an interior space?

SaferDan

Its for the outside, I want some nice orange sunset light coming through the windows.

Is there a better way to do this?

SirCalalot

You can just put in a Directional Light rather than its Dominant variant.

UDK is reading it as the primary light source and that's obviously conflicting with something.

SaferDan

I tried just a directional light as well and I still have the same issues!

I have come up with a work around though but just using three spot lights gets me this, which I am happy with -





Thanks for all the help guys, PC is awesome