Home Technical Talk

AO Detail Failure

polycounter lvl 10

Replies

  • Neox
    Offline / Send Message
    Neox godlike master sticky
    as it has a direction it looks more like gi then ao, dunno if you can use a skyllight in xnormal to achieve that look
  • MoP
    Offline / Send Message
    MoP polycounter lvl 18
    Does the tutorial mention that they must be using a huge ground plane to get lots of AO from the ground?
    Basically yours is casting light from everywhere, his is only receiving light from generally above.
  • mLink
    Offline / Send Message
    mLink polycounter lvl 10
    To me it looks like he multiplied the red (or green) channel from his normal map onto his AO Bake.
    Give it a try and see if you get similar results.
    Also, in xnormal you can bake a convexity map and multiply the red channel over the AO, it will giv e you the sharper/smaller details you sculpted in.
  • CastratedWeasel
  • renderhjs
    Offline / Send Message
    renderhjs sublime tool
    that tutorial is really hyped- must be an awesome money making product to the person who started it.
  • CastratedWeasel
  • Ghostscape
    Offline / Send Message
    Ghostscape polycounter lvl 13
    his AO isn't an AO map. That's why it looks different :) He's got directional lighting, and his areas that shouldn't be occluding at all have a medium grey instead of white.
  • MoP
    Offline / Send Message
    MoP polycounter lvl 18
    Yeah, it's very strange actually (probably not a good thing to promote in a tutorial) since for ambient occlusion you usually only want the generic AO since your in-game lighting should provide all of the "larger" light forms. You're basically just pre-darkening your whole asset by doing it like it's shown in the tutorial, which doesn't make much sense to me.

    Riki (the guy who does these tutorials, AFAIK) is a member of Polycount - maybe if he's reading, or people who know him are reading, he could provide an explanation for this method of lightmap baking, and why he uses this technique rather than the more common one?
  • Seaseme
    Offline / Send Message
    Seaseme polycounter lvl 8
    Yeah.. I've never understood his AO. I once watched the tutorial trying to figure out what was going in.. It's not especially clear about it. It would be interesting to see some feedback from Riki. I'm curious too.
  • Ghostscape
    Offline / Send Message
    Ghostscape polycounter lvl 13
    I haven't watched his tutorial, but he may not be "pre-darkening" it if he's mixing that "AO" map with a soft-light or overlay layer in photoshop. If that is the case, then that middle grey will be missed, and he'll be baking some shadows and some directional lighting into the image, but at least he wouldn't be darkening the image 50% like he would if he was using that with the usual multiply-down method.
  • CastratedWeasel
  • CastratedWeasel
  • LEViATHAN
    Offline / Send Message
    LEViATHAN polycounter lvl 11
    It's not a problem as textured geometry will be placed over it.
  • GoSsS
    Offline / Send Message
    GoSsS polycounter lvl 14
    Well i fail. Just checked the tutorial again and he made a plane for the ceiling and for the ground. Ill have a play around with some of the suggestions for better results u guys put. Cheers :D

    Try deleting the ceiling plane. Only keep the floor plane. It should resolve your problem.
    MoP wrote: »
    Riki (the guy who does these tutorials, AFAIK) is a member of Polycount - maybe if he's reading, or people who know him are reading, he could provide an explanation for this method of lightmap baking, and why he uses this technique rather than the more common one?

    I don't know him but I think it's because his pillar will always be placed on a ground and lights coming from under the pillar are not really usefull.
  • CastratedWeasel
  • Ghostscape
    Offline / Send Message
    Ghostscape polycounter lvl 13
    Ive just checked the texture file that comes with the tutorial and the AO map is set to 'pass through' which basically just shows the shadows without the grey unoccluded parts and without predarkening the image. It looks v. sexy if i may say so myself. :D

    My occlusions are lookin better now, ive done some editing to get the shadows showin nice but i was just wondering about this: vvv

    new1occlusion.jpg

    For some reason, i keep getting the image of my pipe and wirebox onto a bit where it should just be a shadow. Could someone help me out a little plz :P

    EDIT: His ao map is actually set to hard light. Was reading the wrong thing.
    EDIT 2: The 'group' all the ao maps are in is set to 'pass through' but his actual ao map is set to 'hard light'.

    You will have geometry there so you can ignore it. You might want to fill the interior with the same shadow color to avoid any interpolation issues.

    It makes sense that he's using that map with a Hard Light as that will ignore the grey values. It isn't a "proper" AO bake, however, and will cause issues if there is extreme lighting in the scene. It is a valid technique in the sense that it produces a nice looking end result, but it is atypical and can cause issues with the asset being portable to different lightning environments, and thus wouldn't be a useful workflow for, say, an exterior piece, or a ground-lit piece.
Sign In or Register to comment.