Baking GI always causes ugly artifacts, even on ultra settings in unmodified HDRP sample scene

Unity Engine
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1

I’ve been struggling to bake good looking lightmaps in Unity for years now, and I always thought my poor modelling and UV mapping skills caused my baked lighting to look terrible.

But now I’m not so sure any more, because I can’t even get good looking results out of the 2021.2 HDRP sample scene. The pre-baked lighting that comes with the scene looks great, but that quality seems to be completely unachievable with Unity’s lightmapper. Just look at these comparison shots:

7919935--1010584--corner-original.png
7919935--1010584--corner-original.png1211×638 1.03 MB

7919935--1010587--corner-baked-ultra.png
7919935--1010587--corner-baked-ultra.png1211×638 1.03 MB

7919935--1010716--original.png
7919935--1010716--original.png1211×673 237 KB

7919935--1010713--baked.png
7919935--1010713--baked.png1211×673 237 KB

I didn’t modify anything in the scene, I only cleared the baked lighting and regenerated it on LightingSettings4Ultra, the highest settings that are provided by the HDRP sample scene template. These are also the settings that the interactive tutorial uses to teach the baking process, so I’m pretty sure they are supposed to be used. I also tried the ultra settings with CPU mapper, as expected it just took way longer without any noticeable quality improvement.

So what is going on here, was the sample scene baked using even more samples than you get from the ultra settings? Would that even affect these artifacts? Or do you have to invest in a third-party lightmapper like Bakery if you don’t want your Scene to look like this?

Here are the mentioned ultra settings for reference:

7919935--1010596--lighting-settings-ultra.png
7919935--1010596--lighting-settings-ultra.png633×956 64.1 KB

2

Indirect lights(area light, emissive materials) has too much noise
So you must increase the indirect samples higher than 10.000 samples to have less noise
Or simulate indirect lights using spot lights:

3

Thanks for the reply, but that just does not seem to be the case at all.

Here is the result of a 15K indirect samples bake:

7922608--1011139--15k-samples.png
7922608--1011139--15k-samples.png1210×673 209 KB

The quality is no closer to the pre-baked lightmaps that came with the scene, the higher sample count actually significantly worsened some of the artifacts compared to the standard ultra settings.

I suppose the spot lights could be a solution, but my goal is not to improve the lighting setup of the sample scene. I want to know why I can not achieve the pre-baked quality that was generated under these exact lighting conditions.

4

Try CPU lightmapper. The quality of the GPU lightmapper is much lower from noise side

5

Disable filtering and increase samples until the results are free of noise.

The person that named those settings ‘Ultra’ was obviously drunk.

Also the HDRP sample scene is horribly set up for lightmapping, I can only guess even more people were drunk.