Lighting Issues in URP caused by Directional Light

Unity Engine
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1

Hi, I have a question about some lighting issues in this scene. There are strips of light where there shouldn’t be being cast by the directional light. (Next to the windows.)

MathAndMartians_11
MathAndMartians_111920×1080 660 KB

Details:
We are utilizing the Universal Rendering Pipeline, and I’ve applied a mixed lighting approach where some details are baked like ambient occlussion but I also rely on reflection probes since many of the textures are metallic. In order to solve a different issue, I used the URP pipeline asset to set the normal bias and depth bias to 0 under the shadows section. It seemed to help this issue somewhat actually, since it was more pronounced previously, but not all the way.

The meshes all have thickness and there are no gaps. I’m not an expert in lighting, so I’m not sure how to resolve this issue, and am looking for some advice on how to address this.

2

It’s hard to be sure what is going on based on the information given but here are some things to try.

  1. Is the lighting coming through the windows for the simple fact that they are transparent? If so, that sounds like the expected behaviour to me. Let me know if I’m misunderstanding anything here.
  2. What happens if you move a opaque box in front of the “windows”?
  3. Try playing with the window material. What happens if you change it to be fully opaque?
  4. You can try inspect the generated shadow map using Unity Frame Debugger (Unity - Manual: Frame Debugger). Do you see something unexpected there?
3

Consider marking some objects as casting shadows with both sides, this can help with those leaks.

Also double check if the problem occurs with the basic unity lit shader (assuming your shaders are custom), if not it might be a shader issue.

You may also need to adjust the normal bias on your lights.