Light artifacts on meshes

Unity Engine
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1

Hello,

I have unwanted light artifacts on my meshes as you can see on the first screenshot.

9158111--1273772--scene-view.png
9158111--1273772--scene-view.png1490×605 156 KB

Here are few screens for context:

9158111--1273763--baked-lightmap.png
9158111--1273763--baked-lightmap.png1487×603 401 KB
9158111--1273778--uv-overlap.png
9158111--1273778--uv-overlap.png1488×605 69.6 KB
9158111--1273775--texel-validity.png
9158111--1273775--texel-validity.png1489×602 201 KB
9158111--1273769--light-settings.png
9158111--1273769--light-settings.png1943×1028 87.3 KB

I tried changing a lot of parameters based on what I found on other threads but nothing worked except :

  • Increase the scale of individual lightmaps
  • Activate “Generate Lightmaps UVs”.
  • Increase “Min Lightmap Resolution”.

I will add the screens in comments below

But the result is still not perfect. Should I increase the scale again ? I feel like this is not the right solution.

2

9158117--1273817--artifacts-after-lightmap-uv-scale.png
9158117--1273817--artifacts-after-lightmap-uv-scale.png1489×558 166 KB
9158117--1273820--individual-lightmap.png 9158117--1273823--mesh-lightmap-settings.png

3

As long as they are not the same mesh the results will never be perfect, but I would also completely disable filtering and bump up the sample values until the results look clean (which may result in pretty long bakes).

4

Hello,
Thanks for your reply!
Disabling filtering is worse as you can see, even if there is an artistic side :
9162662--1274867--filtering-removed.png

Ok for you it’s something normal this kind of artifact for a simple mesh like a flat wall.
I’ll try to make a single mesh and remove unnecessary edges.

5

That looks like you need a lot more samples as I said in the previous message.

6

I’ve tried 60,000 samples, but without filtering, it’s still not very good.9164639--1275239--samples-bumped-result.png 9164639--1275236--samples-bumped-light-settings.png

I added filtering and it’s still not good, but it’s better:
9164639--1275263--samples-bumped-filtered-light-settings.png

But I got a new behavior when I am far from the object, which becomes brighter:
9164639--1275266--bright-door.png 9164639--1275269--close.png

7

The seam seems less obvious though :slight_smile:

Do you have small emissive materials? With 60k indirect rays things should be fairly clean under normal circumstances (although going to a lot higher values than that is not uncommon).

Don’t bump direct samples that high, keep it to, say, 1024.

Filtering loses informations and blurs the results.

8

I removed emissive materials I had and bumped to 260k indirect samples
9164744--1275311--samples-bumped-result-2.png 9164744--1275314--samples-bumped-light-settings-2.png

Here is the UV charts which was missing in my first post.
9164744--1275320--uv-chart.png

9

If you move the light 20cm downwards, does the noise go away?

10

Hello,

Yes it goes away !! Thank you for taking the time to reply.
Is it because the light makes artifacts as i passes through the mesh ?

Here’s the result, as you can see, I’ve added a new point light to compensate for the fact that the real light is downwards.

9165473--1275458--scene-setup.png
9165473--1275458--scene-setup.png1490×559 227 KB

I still have some minor issues for meshes with borders, I’m trying to increase the “Max Bounces” setting and samples to solve it. I’ll keep you in touch.

9165473--1275455--samples-bumped-result-3.png
9165473--1275455--samples-bumped-result-3.png1490×557 164 KB

9165473--1275464--samples-bumped-result-3-2.png

11

Either it intersects with the mesh (especially if you use soft shadows), or it’s because it hits the mesh at a real close distance which causes high intensity indirect rays to flood the scenes which are generally a pain to resolve.