Distance Field AO total bad in scaled meshes

The distance field AO works fine with normal size meshes, if you scale the mesh to x20 times the original size or 50 for big rocks then the problems start, total absurd 10m shadows in some points in the vertex or the mesh etc…

Hey Hevedy,

I scaled up the basic sphere mesh by 100 and didn’t see anything terrible. Would you mind sharing a screenshot comparison of the issue before and after scaling the rock so I can visualize the issue.

Would you mind testing this with the shapes in the basic tab just to make sure this isn’t an issue specific to your content.



No idea why I expected to you use the only mesh that can’t shwo problems, a sphere that don’t even generate a different Ao at normal scale xD

You need to use a irregular mesh like a rock or somethign with cavity etc

Distance Fields don’t work well for really large scale meshes. This isn’t a bug and is also covered in the documentation for DFAO and RtDFSS.


You have to understand that when we don’t have sufficient information provided we default to using generic assets for testing to save time. If you explain in detail what you are seeing or even better provide screenshots that will save a lot of time for both sides. In fact I highly encourage sharing screenshots of any visual issue you get in the future.

Here is a screenshot of me using a few rocks scaled by 50 and there doesn’t appear to be any major issues other than the cavities get overshadowed. As Tim mentioned this is expected and is a result of large mesh sizes as stated in the Trouble shooting and quality section in this [page][1].

You can help the AO artifacts by adjusting the “Distance Field Bias” or the “Distance Field Resolution Scale” in the static mesh asset.(make sure you hit “apply changes”

I scaled up the mesh further and removed the directional light to show the issue so it is easy to see. Here is a before and after shot when changing the default settings.

In the future when you say things like “My rock looks bad when scaled up” that doesn’t necessarily tell us what we need as a rock could be any shape really. The important thing to note in this case is the cavities in the mesh were getting AO artifacts. Next time please provide relevant information or screenshots and we can as a result give better responses.

Also, it is important to know that even if you adjust these settings its going to be hard to get quality results with large meshes. This is stated in the documentation and not a bug with the engine.

I hope that clears things up,

Well as first point the rocks never are perfect spheres.

Second point “My rock looks bad when scaled up” that sentence is not mine.

As second part your “fix” don’t fix nothing since you edit it per mesh, the scaled meshes will need different parameters since are baked for one mesh, should have a parameter that auto calculates with the scale or you can change the parameters in the details panel.

So at the end is a leak/bug or it bananas I already checked the documentation, that is why i posted that here.

So is a engine limitation sounds like…