Dynamic Light Bleed Through Ceiling at Angles

Development Rendering
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1

I have encountered this issue many times before, but with the static lighting that was possible in those scenarios I was able to work around it - however in this project the entire playspace is dynamically generated and so is not work-aroundable.
I have a room that is randomly generated, with a ceiling on top of it.
At certain angles and as you get closer and closer to the edges of the mesh, bits of the mesh seems to stop blocking the dynamic directional light, and light bleeding occurs to an extreme extent that eventually - at the very edges of the room - completely ignores the roof and all light goes right through. (Please see below)

I’ve tried all possible things I can think of including; setting two sided, increasing height of ceiling, increasing shadow resolution (which of course isn’t even practical in games where people have low-powered PCs), and many other things - however none even help in stopping the bleeding.

Any help would be greatly appreciated.

2

Try to keep Dynamic Shadow Distance Movable in sun’s settings as short as possible.

When you expand 2nd tab in sun’s options (Light), there is a Shadow Bias setting. Try to experiment with that.

If nothing helps, you could model the wall modules so perpendicular polygons intersect themselves a bit.

3

I’ve actually already got bias at 1 - I’ve tried intersections and they also don’t help much - and I need to keep the light’s distance quite large as the randomly generated area in which the player plays can get quite large.

4

I see. Maybe it’s a stupid idea but… how often do you need sunlight here? If modules with windows are scarce, it can help to use a spotlight outside each windows instead :slight_smile:

5

As each cardinal side of the office floor is glass I need to use a directional light (also because there will of course be other buildings outside the windows - and regardless, there should be a way to fix it.