How do you effectively build stationary lights so as to not cause problems with Skeletal Meshes?

Don’t know why but when I build the lights all stationary lights start to behave strangely. I recorded a video of the problem…

Any idea of what’s going on?


I have noticed this as well in the Shooter demo (on the arms/weapon).

It’s annoying me… if I decrease the Attenuation Radius (scaling it down) the problem disappears, but the scene stays in the dark. ¬¬

Hey fireapache,

Stationary lighting has a few different elements to consider when placing it in your map. How many static lights do you have overlapping in your map? The problem may be arising from that, as described here:

Hope that helps!

Ben Halliday

I appreciate the answer but the problem isn’t light overlapping (images below). The light interaction stops when movable object are under the light and cast dynamic shadows is marked (video below). The problem happens with all stationary lights in the scene!



I think this issue might be related to light culling. I’m still very new with UE4 so I’m not sure if this is something that can be fixed with tweaks or not but you might want to try using a precomputed visibility volume and also a lightmass importance volume and then bake to see if this solves your issue.

Thanks, I’m starting too. Nope… I had a Lightmass Importance volume in my scene, but even with a Precomputed Visibility volume in place the problem still the same.

Video: - YouTube

When you build lighting, dynamic objects switch over to per-object shadows from stationary lights. These per-object shadows use the bounding box of each object to orient the shadow map. From your video (which is great at showing the problem btw) it looks like your mesh doesn’t have valid bounds. For skeletal meshes you have to make a physics asset to get good bounds at runtime. You can use ‘show bounds’ to see the bounds of everything in your scene. Hide everything except the skeletal mesh to make it more clear. I expect you will see very large and rapidly changing bounds for the skeletal mesh.

It’s solved, thank you very much Daniel!

Video: UE4: Stationary Light Problem Solved - YouTube