Baking AO, what options do i have?

Visceral

Hi fellow polycounters. Probably an obvious question to all of you, but before that im going to explain the situation.

Im making a bunch of models, theese models have no "highpolyversion" and i want to bake an Ambient Occlusion pass for them. However when i try to bake in max its ALLWAYS freezes when i try to make a test render its allways at 13.3% and im using the Mental Ray method.

I have also tried doing this in xNormal, but since i have no highpoly the ao comes out....well really really weird.

What options do i have to bake my AO? Is there anyway i can make this work in Xnormal without a highpoly or do you guys recoment an alternative method in Max, or should i look for a third party app?

Thanks.

JFletcher

Have you tried using the Low poly model as the high poly source in xNormal?

Also try just using the scanline renderer in Max, with a skylight and light tracer turned on in the render settings.

Visceral

JFletcher wrote: »

Have you tried using the Low poly model as the high poly source in xNormal?

Thats what causes the AO bake error, it dosnt render a map if no mesh it put into the Highpoly slot.

JFletcher

You said the AO comes out very weird, do you mind posting a pic?

Check to see if you are baking to the right UV channel. (sometimes by default Max has it to channel 3)

Eric Chadwick

Some methods here
http://wiki.polycount.com/AmbientOcclusionMap

Visceral

thanks, i might give a look at light tracer. but first im gonna post the pic.

JohnnyRaptor

Visceral wrote: »

Thats what causes the AO bake error, it dosnt render a map if no mesh it put into the Highpoly slot.

think you missunderstood what he means.

He means load your lowpoly mesh in to both High and Low tabs inside xNormal, then bake.

Bruno Afonseca

I use renderhjs' textools to do that. Way easier!

Visceral

JohnnyRaptor wrote: »

think you missunderstood what he means.

He means load your lowpoly mesh in to both High and Low tabs inside xNormal, then bake.

thats exactly what i did.

Mark Dygert

So that image is from Xnormal or MentalRay AO? If its MR/AO it seems pretty huge. Have you tried rendering a smaller size like 128x128 with smaller samples like 8 or 16. It sounds like your settings are probably cranked and its not hanging but just taking longer than you're willing to wait to solve an area.

What are the RTT settings? Printscreen/dropbox?

shinobix

Vig just sent me a few links that were really helpful. Check out my thread, and see if any of those links help you. They really helped me!

http://www.polycount.com/forum/showthread.php?t=76895

Visceral

Vig wrote: »

So that image is from Xnormal or MentalRay AO? If its MR/AO it seems pretty huge. Have you tried rendering a smaller size like 128x128 with smaller samples like 8 or 16. It sounds like your settings are probably cranked and its not hanging but just taking longer than you're willing to wait to solve an area.

What are the RTT settings? Printscreen/dropbox?

that is the image i got from xNormal, while having the Low Poly and the Highpoly as the same mesh. All my test renders are done as 256x256 it dosnt solve anything.

Visceral

Ok never mind, i seem to have solved it now. The errors are still there, but i rendered with the complete map method instead of MR Occlusion settings and now it seems to work and i get no errors. Thx everyone for your time.

Mark Dygert

Saving out a complete map will bake the scene lighting into the model, if no lights exists then the default viewport lighting is baked. If you don't have lights set up in the scene then you should.

I think your errors might be coming from the UV layout and it might be using the wrong channel.

Visceral

Vig wrote: »

Saving out a complete map will bake the scene lighting into the model, if no lights exists then the default viewport lighting is baked. If you don't have lights set up in the scene then you should.

I think your errors might be coming from the UV layout and it might be using the wrong channel.

The channel is allready checked, but since im trying to save texture memory i used some overlapping faces. Theese where only used on areas where i know it looks the same on both sides and would have identical occlusion anyhow.

Eric Chadwick

Well the way Max's RTT works, this will cause errors since it renders the lighting in _UV space_, so any overlapping faces will cause multiple renders to occur for the same image, because it renders each and every UV face it finds within the 0-1 UV square.

Best bet is to take the faces you don't want to render, and move them 1 unit outside the 0-1 UV square. Like this: http://wiki.polycount.com/NormalMap#UV_Coordinates