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Maya Ambient Occlusion help - faceted results

Emil Mujanovic
polycounter lvl 18
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Emil Mujanovic polycounter lvl 18
I've been bashing my head against the wall trying to figure out what it is that I'm doing wrong. I'm trying to bake out some AO for a lo-poly character and I always get a faceted result, like I have all my edges set to hard edges (no smoothing groups).
I've done this a tonne of times in the past with far less dense mesh and have gotten a smooth result. I've experienced this a few times before, but for the life of me I can't remember what I did to solve the issue.

Instead of typing out my process, it's pretty much the same as this.

I'm using Maya 2008 SP1 64-bit

Things I've tried:
- new scene
- default Maya settings
- various settings based on AO tutes I found online
- new mesh (standard primatives - sphere and plane)
- unlocking normals
- conforming normals
- re-smoothing the mesh

If anyone has encountered this before and has a solution, I'd be forever in your debt. If I'm imagining that you can get a smooth result from a lo-poly mesh and just think I remember getting smooth results, then let me know as well.

Here's an example of what I mean by faceted results:
ao-error.jpg

Thanks.
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Replies

  • ZacD
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    ZacD ngon master
    export as an obj and re import it in a new scene?
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  • kodde
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    kodde polycounter lvl 19
    Try using the Color > Batch Bake (mental ray) feature instead, see if that changes anything. It's found in the Polygon module. Set it to "enable bake override" and switch from Lights Only to Occlusion.

    Good luck.
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  • bgoodsell
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    bgoodsell
    Do you have your normals smoothed at all? That usually fixes mine if I select all the edges and go normals-soften edge and then bake my AO.
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  • CheeseOnToast
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    CheeseOnToast greentooth
    Hey Emil, not the answer you're looking for but I'd suggest you use Xnormal instead. I spent ages trying to get decent AO bakes from Maya. You can get a consistantly good one from Xnormal very easily and quickly, so give it a try.
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  • MoP
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    MoP polycounter lvl 18
    Also Maya's baker is one of the slowest in the world, you will probably be able to export to XNormal, fiddle with the settings, do a few test bakes then do a final bake at double the resolution before Maya would even have finished baking one AO map...
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  • malcolm
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    malcolm polycount sponsor
    I've found the batch bake mental ray occlusion setting extremely buggy. Here is how I do it in maya successfully.

    1. Create lambert shader set colour to white.

    2. Create mib_amb_occlude node from mental ray nodes

    3. Plug mib_amb_occlude node into ambient colour of lambert.

    4. Mental ray batch bake light and colour.

    5. Also if your spread is set higher than 1.0 you will get faceted ao as it will probably start occluding back on itself depending on your model.

    Mop's answer is a good suggestion. I've recently done a lot of exploration of maya's ao baker it is fucking uselessly slow. Xnormal's gives the same results in a fraction of the time, althought he interface is completely overwelming for the first 10 minutes. Maya 2048 map over night, xnormal 2048 map about 15min.
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  • CheeseOnToast
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    CheeseOnToast greentooth
    Yup, and when you're dealing with high poly meshes, forget about using MR batch bake. It might as well be a "crash me" button for all it's worth.
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  • throttlekitty
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    throttlekitty
    malcom, (or anyone, I suppose) what settings are you using in xNormal for baking? My last 2048 bake in xN took many hours.
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  • CheeseOnToast
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    CheeseOnToast greentooth
    How many rays are you using? You don't need as many as you might think. 512 usually gives very decent results, maybe going up to 1024 for a very smooth bake with zero banding. You can often get away with much less though, especially with jitter on if you don't mind/want a grainy bake.
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  • Emil Mujanovic
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    Emil Mujanovic polycounter lvl 18
    Thanks a bunch for the replies. A lot of solid suggestions which I'll investigate with my next bake and will also look into xNormal. I've heard it being suggested and recommended a bunch of times for a variety of different things, so I may as well give it a go.
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  • malcolm
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    malcolm polycount sponsor
    throttlekitty, I did a high to low bake with 1024 rays I think?
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  • walter
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    walter polycounter lvl 15
    The problem of the Maya Transfert Map tool that it's not multithreaded...
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