Can't use Ambiant Occlusion in Render to texture max 2018 Help

[justinmanas]

When using render to texture I switch to Mental ray and then I get the ambient occlusion setting, but in max 2018 the render button is just greyed out no matter what render-er I set it to. I need to bake ambient occlusion and I can't find anyway to do it. Any help would be great thanks?

[alexei.dmitriev.k]

Facing the same problem now. Would love a solution when one arises.

[hagen.deloss]

Hello @justinmanas

Are you looking to render an AO map using Arnold or Mental Ray? are you looking to include bounce lighting in your AO map? I found this tutorial on how to set up Arnold AO material in 3DS Max that hopefully is helpful!

If you could post a screenshot of your render setup, with your Arnold AO material settings, I can help you troubleshoot further.

Please select the Accept as Solution button if my post solves your issue or answers your question.

[alexei.dmitriev.k]

So if I understand correctly, I have to switch to a Arnold based pipeline to be able to bake a itching that is Ray traced and/or has GI? No other solution for now?

[hagen.deloss]

Hello @alexei.dmitriev.k and @justinmanas

We support Mental Ray 2015/2016 since Arnold was brought on in 2017, and unfortunately Arnold wasn't designed to render materials to a texture map. I do see that in our documentation that rendering AO maps to textures should be available in Mental Ray. Furthermore, I can see what you are running into with the render button being unavailable.

I will look into getting a copy of Mental Ray and testing it out further, but in the meantime I would check out the Nvidia rendering forums.

If you export your object(s) into a new scene and recreate the AO map you want to render to texture, you can retain your original scene while still getting a high res AO map rendered to a texture using the scanline renderer. You can then map that AO pass into your original Mental Ray scene!

Thanks for working with me on this, looking forward to hearing about the results of your project!

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Smallpoly]

As of August 10th 2018 Arnold has Render to Texture support via version 2.1.945:

https://support.solidangle.com/display/A5AF3DSUG/2.1.945

To update, grab the new version from their download page:

https://www.solidangle.com/arnold/download/#3dsmax

[hagen.deloss]

@Smallpoly

Awesome, I saw that! Have you gotten a chance to play around with rendering out an AO pass with the tools?

That would indeed be the exact solution to this issue 😉

[Smallpoly]

I've been looking into it a little bit today - they haven't ironed all the bugs out yet. The bake is getting affected by the lighting instead of just rendering out the raw render element. Having a flat white ambient light that's able to affect the rendered scene should allow it to bake out clean maps, though I'm still in the process of testing out the ideal setup for that.

Adding the Mental Ray AO element will produce an evenly lit AO map, but that's not ideal yet either. It seems to be ignoring the range parameter right now.