Baked Ambient Occlusion Map too Grainy

Support Materials and Textures
1

So my baked gradient map is too grainy. What settings do I need to use in order to get smoother gradients?

my ao map;

AO-Map-test1
AO-Map-test11024×1024 675 KB

My settings;

AO-Map-settings1-Screenshot_20230209_070712
AO-Map-settings1-Screenshot_20230209_0707121920×1080 1 MB

AO-Map-settings1-Screenshot_20230209_071823
AO-Map-settings1-Screenshot_20230209_0718231920×1080 645 KB

I’m using Blender 3.3 and is on Kubuntu 22.04. Any help would be greatly appreciated, thanks.

2

This bake looks like some glitch might be happening, not just a lack of quality. Make sure your model has no overlapping faces, has its normals pointed in the correct direction and has clean UVs.

Then, the settings that will affect an occlusion bake:

  • The noise treshold. a lower number means higher quality. Or you could deactivate it completely, which will ensure every part of the image renders to max samples (longer bake, best quality).
  • The “fast GI approximation” section. This setting is normally used to replace indirect light with ambient occlusion, but its distance setting is also used when baking AO, even if fast GI is not in use.
3

I think I just saw an other possible cause in your images. In your outliner, I see you have 2 versions of the model, one of them deactivated in the viewport. However, it is still visible in the render, which will affect the bake. If the 2 models are overlapping, you should disable the render visibility of the one that’s hidden, or the 2 overlapping surfaces will be visible in the end result.

4

thank you @etn249 do i hide the hi poly mesh as well when I bake the normal map?

5

The baking process is actually rendering. You have not disabled your low poly mesh for rendering, you only hid it. That leads to your follow up question. You usually want to bake from high to low, meaning bake the ao map from the high poly mesh and use it afterwards on your lower poly meshes.

6

what if the high poly and the low poly does not use the same uv map?

7

Thanks @etn249 for the tip on ao baking. i’m getting much better results now;

AO-Map-test3
AO-Map-test31920×1080 1.01 MB

8

They need to share the same uv map, because the baked maps rely on a uv map layout and if this is not the same for both meshes, you will effectively “move your baked maps all over the mesh”. That’s the same with any other baked or object specific textures - move it or map it differently and it will fall apart.

9

If you are baking the normal map from high to low, you will need to have both visible.

10

thank you very much