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Spec & ambient occlusion maps how do you make'em?

polycounter lvl 18
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Lee3dee polycounter lvl 18
what the best method for creating spec maps & ambient occlusion maps? Is there a science behind it? Is this something that you can render to texture in Max as a starting point?

Any tips or tutorials on making these would be greatly appreciated :)

Thanks
-Lee

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  • Ged
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    Ged interpolator
    I heard kite say something about rendering a spec map from zbrush during that little 3d mini for dom war, Id like to know more about stuff like that too
  • pior
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    pior grand marshal polycounter
    Woo just lost my post!
    Personally use 2 sources.

    1-an actual AO render from Xnormal
    01-ao.jpg

    It is mostly white everywhere, and dark in the crevices. It is very spread out and subtle.

    2-a normalmap >>> "fake AO" conversion done in Crazybump. The differences with the above usual AO bake are :
    -Mostly focused on medium and small edge detail,
    -Picks up both pits and peaks, uses a 50% grey for everything inbetween.

    02-tantoao.jpg

    By combining these two textures you can go quite far, very fast. Spec values will mostly come from a dark ctrl-L pass on that base common texture.
    03-comp-spec.jpg

    Good luck!
  • Sa74n
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    Sa74n polycounter lvl 18
    is there a way to render ao without getting that annoying shadow around floaters?

    regarding the process: depending on the texture i sometimes use the highpass filter to push the contrast around edges.

    pior: do you still use this or a similar technique? http://www.pioroberson.com/tuts/tut_texturing_tricks.htm
  • MoP
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    MoP polycounter lvl 18
    I do basically the same thing as Pior. AO bake, Crazybump pass over the normals, always forms the basis of my specular.

    I tend to use layer masks for most of my texture work so instead of doing a Levels pass on the diffuse, I'll just make new layers using the same layer masks, fill them with appropriate colours, then duplicate the texture overlays which were used on the diffuse.
  • pior
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    pior grand marshal polycounter
    Sa7an : not really anymore no :P
    Must faster with today's tools!
    As for the floaters I did not clean them on that example, but it is really fast to do. A matter of minutes most of the time.
  • PolyHertz
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    PolyHertz polycount lvl 666
    Well if the floater ao is being a problem just render two maps, one with and one without them. Then you can use the 'clean' map as a wholy masked layer over the other in photoshop and just un-mask the areas you want to remove the shadows from on the 'dirty' map.
  • Mark Dygert
    To get rid of floater shadows you can do like PolyHertz suggested, only with one change to make things easier. You hide or get rid of the rest of the mesh when you render the floaters. Makes combining them much more simple, provided nothing casts a shadow on your floaters...
  • Lee3dee
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    Lee3dee polycounter lvl 18
    thanks guys.

    Ok. The crazybump fake AO, do you multiply the spec map on top of the normal map in Photoshop?
  • ImSlightlyBored
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    ImSlightlyBored polycounter lvl 13
    normally do very similar steps to whats been said but also just keep spec map in mind when I'm making my diffuse, so I mark up some layers to be used in spec etc. It's easier, for me, to work on spec and diffuse at the same time.
  • Lee3dee
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    Lee3dee polycounter lvl 18
    so the spec doesn't need to be full white, grey, etc. Only those highlighted areas that would receive light would be shown correct? Sorry for asking all these noob questions, i'm trying to learn this stuff, been making levels for too long. lol
  • ImSlightlyBored
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    ImSlightlyBored polycounter lvl 13
    nah, those that use plain colours - ie pure white, pure grey, are spec level/gloss maps. They affect the size of the hotspot and in terms of UE3 (for example) work on 0-1 values.

    A spec map can contain unique details in it, like, say, fingerprints on metal, or footmarks on concrete floors, would show up nicely. But they also need to be considered that the darker it is, the less it'll show up. Also, what I like to do, is use the A channel in my spec map for a gloss map (as mentioned above) for more material definition.

    Someone once said that an easier way to see what you spec map will look like is to use it as a certain layer mode in photoshop - dont know if thats true, and I think it was linear dodge mode but i cant remember fully.
  • PolyHertz
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    PolyHertz polycount lvl 666
    ImSlightlyBored: That was Tinman your refering to, I know cause I saved the text :p
    This is what I had saved in my notes on previewing spec:

    "Place spec map in a layer_set over the diffuse, and set the layer_set to color dodge.
    While painting the spec you'll see approximatly how hot that surface will get with specular, then you just set an action to switch the specular layer_set to a pass through, save out specmap, and change it back to dodge to continue working on it."
  • Ged
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    Ged interpolator
    hmmm sounds like an interesting method, whats a "pass through"?
  • Xenobond
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    Xenobond polycounter lvl 18
    'The Pass Through blend mode blends any layers within the set and then continues blending with layers outside the set.'

    as opposed to Normal-
    'Using Normal blending on a layer set treats all the layers within a set as if they were a single layer that is then blended normally with other layers outside the set.'
  • Ghostscape
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    Ghostscape polycounter lvl 13
    Sa74n wrote: »
    is there a way to render ao without getting that annoying shadow around floaters?

    regarding the process: depending on the texture i sometimes use the highpass filter to push the contrast around edges.

    pior: do you still use this or a similar technique? http://www.pioroberson.com/tuts/tut_texturing_tricks.htm

    I find its easiest to render a skylight pass in Max - this gives you a decent AO pass (I use a mentalray AO as well) that doesn't give you shadows around your floaters as it uses a different calculation method for its shadows. Then I just mask between the two, using whichever gives me a better result.
  • Ged
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    Ged interpolator
    wow xenobond somehow Ive never ever noticed the "pass through" option in the blending modes.
  • glib
    Ged wrote: »
    wow xenobond somehow Ive never ever noticed the "pass through" option in the blending modes.
    It's what a group defaults to.
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