Lightmap looks different between built-in pipeline and URP

Unity Engine
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1

Hi. I have some problem about lightmapping.

In my project, I merged lightmap texture to diffuse texture for LOD mesh, by generating new textures (pre-multiplied lightmap pixel values).

With built-in pipeline, this works well regardless of project’s color space (gamma or linear). It looks similar the original texture with lightmapped and pre-lightmapped LOD texture.

But URP with gamma space, it shows different result. The color is very different between original and LOD. (URP with linear space works without problem, like built-in pipeline)

So I wonder that URP’s lightmap calculation in gamma space is changed? any documentation about this?

Thanks.

2

I think URP lightmap in gamma space should match the built-in. Could you prepare a small test case and file a bug?
And we’ll take a look.

3

@eHaka I found that this issue is related to SH value, not lightmap itself.

My LOD shader contains SampleSHPixel() and it makes final pixel value incorrect. So I removed it and now works correctly.