topic Re: AO baking using Turtle causes projectionartifact on UV border in Maya LT Forum

AO baking using Turtle causes projectionartifact on UV border

Anonymous — Fri, 05 May 2017 12:45:17 GMT

Hi People

I am using baking AO using turtle and the "ilrOccSampler" for a while now and the same artifacts keeps occurring.

Wherever there is a UVshell border, the AO sampler creates a nasty seam when this border is on a rounded surface. As seen in the example below:

Note that the uvs are well dilated and the normals on the ball are all smooth. This artifact starts getting very apparent when using a bit more complex models:

We have seen that disabling adaptive sampling in the AO sampler creates the best results but no other setting completely removes the seam. For now the only solution seems to be hiding the UV borders as much as possible.

From our point of view it looks like the ao sampling does something weird when it comes to UV borders... as if it cuts the mesh (which in theory is correct) thus creating a hard edge in the bake.

Using turtle as a AO baking solution has proven very powerful and fast. If this little part could be looked into and fixed we would be happy campers!

If you would have the time to look into this, that would be great!

Thank you,

Laurens 't Jong

Lead 3D Artist

Paladin Studios

Re: AO baking using Turtle causes projectionartifact on UV border

sean.heasley — Mon, 08 May 2017 18:24:00 GMT

You can try toggling off Bilinear Filter and that may solve the issue. However Turtle can have issues especially when baking complex objects, I personally recommend Substance Painter/Designer or Crazybump when baking normals, AO etc.

Re: AO baking using Turtle causes projectionartifact on UV border

Anonymous — Tue, 09 May 2017 08:45:15 GMT

Hi Sean,

Thank you for the reply, but disabling bilinear filtering has no effect on the bake, it only effects the way the final texture is filtered.

I do know that there is software out there that can bake AO correctly but I am pretty sure that Autodesk would not have that as an excuse for not improving their own baking solution. By adding more software to our pipeline just to bake a simple AO map means more work for prepping and exporting models, resulting in loss of valuable production time.

Cheers

Laurens

Re: AO baking using Turtle causes projectionartifact on UV border

sean.heasley — Tue, 09 May 2017 13:34:00 GMT

I understand I just wanted to throw in my 2 cents for my personal workflow when it comes to baking especially for games. I'm still looking into your issue but you can try to follow these steps as well.

https://knowledge.autodesk.com/support/maya/troubleshooting/caas/sfdcarticles/sfdcarticles/Artifacts-when-baking-ambient-occlusion-in-Maya.html

Re: AO baking using Turtle causes projectionartifact on UV border

Anonymous — Thu, 11 May 2017 09:54:31 GMT

Hi Sean,

Thanks again for the reply, I have done some experimentation with the GI workflow although is just not cut it for us.

The neat thing about AO is that it is object centric and not defined by a sky light. This way we can manipulate the amount and distance of the AO rays very exactly and create an easy setup that works in many cases (also for inside scenes) If we would use GI we would have to work with loads of boosted indirect bounces to be able to get some good results.

So, for now we will work around the seams as much as possible... and keep using the occlusion sampler provided by Maya.

Thank you very much for the input and hopefully it is an issue that could be tackled.

Laurens