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Baking Pourous Models [Errors]

polycounter lvl 17
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Incomitatum polycounter lvl 17
Here's the image up front:

WIP_035.jpg

Don't worry about the circular or rectangular error. The main issue here are these diamond shaped holes. They are supposed to have a gentle (nearly rounded slope) and do in the model; but the (rays?) are going all the way back in some cases and catching the lips of other ones.

I have never done a Normal with an alpha before, but my alpha texture has similar issues. I have tried -not- using the cage in the projection properties, I have changed from closest to furthest, and now I am out of ideas and my work is at a stand still.

The lip I have circled in purple is an example of what it catching and showing up in the normals.

Also trying it again now with no padding. :|

Any suggestions?

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  • Incomitatum
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    Incomitatum polycounter lvl 17
    In this instance changing the padding from 2 to 0 fixed the issue.

    EDIT: Well this still wasn't 100%. The alpha was too hard edged with 0 padding and destroyed the point of me using a normal map for the holes at all. :|

    I have never used it, but am going to try XNormal now. :|
  • Incomitatum
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    Incomitatum polycounter lvl 17
    This is what I am getting out of xNormal.

    WIP_TrashCanIssues.jpg

    It will be a pain in the ass, but I am considering plugging all the holes to get the rays to stop, and then manually creating the alpha based on depth. :|
  • sprunghunt
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    sprunghunt polycounter
    A bin like this wouldn't be totally transparent anyway, It would have another bin inside. So you could probably get away with less alpha.

    dust-bin-for-public-spaces-91355.jpg
  • Incomitatum
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    Incomitatum polycounter lvl 17
    In the final model I do add a cylinder like mesh I am going to have as the bag. I might just put that in, try my bake, and see what happens.
  • Mark.N
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    I would unroll the metal grid portion then bake it on it's own as a flat plane to avoid any rays picking up unnecessary details.
  • Incomitatum
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    Incomitatum polycounter lvl 17
    I did half think about that. I don't think I have the skill or patience to unroll it without buggering it up. :S
  • Incomitatum
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    Incomitatum polycounter lvl 17
    So far, it seems like I need to add a cylinder to the inside of the HIGH poly, not the low. Going to try it some more.
  • SHEPEIRO
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    SHEPEIRO polycounter lvl 17
    just adjust the ray distance in xnormal
  • Incomitatum
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    Incomitatum polycounter lvl 17
    I did try to adjust the ray distance in xNormal. I have found it has a way of smearing and cracking your padding, at least out of max your padding is close to something usable.

    So... @#$%^& xNormal, and @#$%^& 3DsMax. In the end the effect was achieved in Crazybump. I spent a LONG time making that high-poly. And HOURS later, it was much easier to hand make each of the hex shapes and dedicate them to a height-map as well as my alpha. The result?

    WIP_036.jpg

    That'll do pig. That'll do.
  • r_fletch_r
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    r_fletch_r polycounter lvl 9
    Jocose had the same problem a few days ago. I posted a fix of sorts in his thread,
    http://www.polycount.com/forum/showthread.php?t=74667

    If your going to use the crazy bump normal map, you might want to ditch the shape recognition data along with all the larger details. just using the fine/medium detail would get you a less squishy more refined looking result.
  • Farfarer
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    You might find that you have to shrink the inner boundaries of the holes.

    Could be that their angle is too close to that of the cast rays so it's barely glancing them and/or pretty much going straight past them.

    Same sort of issue as having to bevel HP models a little so there's an edge for the rays to catch, only exacerbated by the fact it's cylindrical.
  • jocose
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    jocose polycounter lvl 11
    Two Things,

    First, Xnormal has a check box that can make rays not infinite. If you uncheck "closest hit if ray fails" then this problem will go away provided your ray distance is small enough.

    Second, I wouldn't bake this like you are anyways. I would do this on a flat card and then just apply the resulting texture the cylinder. So model out your pattern of holes and make sure that the left and right side of your flat model is the same and then just bake directly onto a single flat polygon, perfect alpha, easy to update and change, and will look fine on the model.
  • Incomitatum
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    Incomitatum polycounter lvl 17
    @Talon,

    You assessment is probably the most accurate a combination of not enough bevel with a curved surface, in conjunction with not having enough texture space to represent what -is- there; exacerbated by the rays in the holes catching opposite edges.

    I have only just now risen for the day and will be working with this model more today.
  • Peris
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    Peris polycounter lvl 17
    perna wrote: »
    I've seen a number of threads like this and though I haven't read all the replies I haven't seen any that state the obvious: Cover up the holes in your hipoly, then bake a diffuse mask for them you can use in photoshop.

    lol yea I was just going to say this, just paint the alpha in photoshop, why make it hard on yourself?
  • MoP
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    MoP polycounter lvl 18
    No, not even paint it. Just put a different coloured object behind it - make the outer mesh pure red "255 0 0" and the inner mesh pure green "0 255 0", and bake a colour map.

    Then you can just CTRL-click the appropriate channel in Photoshop and get a perfect selection in one go.

    I always bake out selection masks based on combinations of colour channels when I'm doing highpoly bakes, it saves loads of time and effort, and is much more precise than doing it in by hand.
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