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Extracting specular and reflectivity maps in Zbrush.

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melviso polycounter lvl 10
Hello,I have been using Zbrush for sometime now and I am very pleased with how awesome it is(never modeling in Maya anytime soon lol).

Okay,I have created a 3d model and I have painted different materials on the model like say I painted with the matcap skin material for the skin and a chrome material for the leather catsuit she has on.I do a low res retopology of the model,uvmap it, and time to extract the maps from the high res one.I noticed that Zbrush uses the multimap exporter plug in.So,I noticed there is a texture from polypaint extraction but no specifics to whether its a color map,specular map,alpha map,refectivity map.Is there a way this can be done or am I missing something?

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  • cryrid
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    cryrid interpolator
    It would export the diffuse/polypaint color only. There are ways to bake color and specular information that come from a matcap, but once they become static they'd lose 98% of the effect.
  • Ace-Angel
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    Ace-Angel polycounter lvl 12
    Cubemap, Specular, etc all rely on Camera/Light vectors, so you need to use shaders to get that effect.

    You cannot and should not bake this stuff, they will lose all effect, if you're going for low end stuff, like iPhone, then hand-paint your highlights, much better.
  • melviso
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    melviso polycounter lvl 10
    Thanks for the replies but I still don't understand what you are trying to say.I can't export the color of the matcap with the postion of the light on it using multicap exporter?It would only export the color I have painted from the rgb channel and not the M channel?
    This is depressing and I spent so much time tweaking the materials to get them to look right and then painted them with only the M channel on the model.Then used the rgb channel to add dirt and discoloration.
    Can someone pls explain this in detail?Why would ZBrush which is so awesome lack this,even Mudbox allows specular,alpha maps.Or should I use GOZ to export the model and its materials to mudbox to extract the maps?
  • cryrid
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    cryrid interpolator
    I can't export the color of the matcap with the postion of the light on it using multicap exporter?
    Most matcaps aren't going to care about the position of the light (which doesn't even exist as far as I understand), just the normal of the surface. If the image is telling it to put a bright specular highlight towards the top-right, then it will always be at the top right of the mesh no matter how you rotate it.
    crappy_zbrush_example.jpg
    Like this. No matter how you move it, the blue is always going to be at the top left and the orange at the top right. So right off the bat that would be a pretty conflicting thing to try and bake to a map.

    There is a trick to capturing a matcap where you basically generate a displacement map, apply it onto a planar mesh, and export that as a texture, but then you'll run into the second problem: all that lighting information is now very static and so it simply wont look anywhere near as good.

    whyyoushouldntbakematcaps.jpg
    It's an even worse effect when to see it in motion.
    Why would ZBrush which is so awesome lack this,even Mudbox allows specular,alpha maps.Or should I use GOZ to export the model and its materials to mudbox to extract the maps?
    Zbrush doesn't work like a typical 3d program. You're not working with a virtual 3 dimensional world, there is no camera to move around, no lights. It's basically just an enhanced image document that you're rotating a model infront of. There's benefits to this (the documentation mentions that this frees up your resources in a way that you can work with even more polygons, and personally I like the things that can be done with 2.5D documents), but at the same time it's going to mean that things like lights and materials will have to function differently as well. I think it's set up more to let you quickly see the forms of the surface you're sculpting and to preview what it might look like as different materials, but when it comes to actually rendering something (especially something you want to take outside of zbrush, and have actual reflections/highlights/etc), you're better off using a renderer that's meant for it.
  • Ace-Angel
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    Ace-Angel polycounter lvl 12
    ZB started out as a traditional painting app with some 3D abilities, but got upgraded to full 3D later.

    Even now, it's not a true workspace environment, everything you see is pretty much faked as much as possible for performance reasons, which is why most of the time, even though it lacks certain stuff, can outperform Mudbox in certain area's.

    Besides, with a proper Normal Map and Diffuse, not to mention a Cavity and AO bake, you can pretty much get all the textures you need, save for Gloss, but that one is easy to manage.

    Just to echo what Cyrid said, use a dedicated renderer/shader for highlights. It's the only solution.
  • melviso
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    melviso polycounter lvl 10
    Thank you so much.Now I fully understand what you are saying.
    Checked around after you explained it and saw this:
    [ame="http://www.youtube.com/watch?v=WS5glTYDYkw"]ZBrush 4 Baking MatCaps Video Update! (Subtittled Version) - YouTube[/ame]


    So basically ZBrush sucks when it comes to extracting maps other than normal,displacement,ao,cavity and diffuse maps.
    So,Mudbox is better for extracting specular,alpha maps or when it comes to texturing.
    Hmmmmm....and I thought ZBrush was better.It's still the best in the modelling department.It can handle way more polys than mudbox.I have used Mudbox myself and I used to have huge file sizes whereas the one I am working on with one character and all her props and weapons is presently less than 100mb.
    I guess the advantage Mudbox would always have over ZBrush is its true 3d space,the ptex stuff,texturing capabilities,and simplicity.

    How about if I polypaint on the model in black and white where I want my specular and reflective maps to be and then use them with a shader in Maya?
  • melviso
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    melviso polycounter lvl 10
    Ace-Angel wrote: »
    ZB started out as a traditional painting app with some 3D abilities, but got upgraded to full 3D later.

    Even now, it's not a true workspace environment, everything you see is pretty much faked as much as possible for performance reasons, which is why most of the time, even though it lacks certain stuff, can outperform Mudbox in certain area's.

    Besides, with a proper Normal Map and Diffuse, not to mention a Cavity and AO bake, you can pretty much get all the textures you need, save for Gloss, but that one is easy to manage.

    Just to echo what Cyrid said, use a dedicated renderer/shader for highlights. It's the only solution.

    Thanks for the explanation.Its like baking lighting and shade information to the diffuse map of your model,so if you import the model into an environment with a different lighting.the model will look bad.In mudbox one can even create alpha maps.
    Can you tell me how one can get these maps from the maps in zbrush?
    But from that matcap tutorial on youtube,the model didn't look so bad?

    *sigh*I feel bad.I have spent close to a month learning ZBrush and then I get to find out about this.Maybe,mudbox wasn't so bad after all,problem is you can't create base meshes in it(have to create base mesh in a different app),no remeshing,or dynameshing.I guess each of them has its flaws.
  • cryrid
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    cryrid interpolator
    People tend to give mudbox the advantage for texturing, especially when it comes to being able to paint things like Specular.
    How about if I polypaint on the model in black and white where I want my specular and reflective maps to be and then use them with a shader in Maya?
    That would work. The main disadvantage is that you wouldn't really get to preview the full effect as you're painting. There is a trick in using a dark, reflective matcap (so with black polypaint you'll just see black, and once you start painting lighter values you'll see more of the reflection), but I can't speak for the accuracy of this method. I tend to do my specular maps in Photoshop using a model viewer to preview any changes.
  • melviso
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    melviso polycounter lvl 10
    cryrid wrote: »
    That would work. The main disadvantage is that you wouldn't really get to preview the full effect as you're painting.

    Exactly..but I have seen several very beautifully textured works where Zbrush users use polypainting and then a low poly was made with the textures.Like this:http://www.polycount.com/forum/showthread.php?t=77580

    Did he paint the textures in Photoshop or polypaint in ZBrush?

    Why can't softwares be awesome and wholesome at the sme time?Grrrrr..!!!
  • cryrid
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    cryrid interpolator
    I suppose you could always ask him personally, but I think he tends to bake the normal map out and then handpaints everything else in photoshop (such as the case for this).
  • melviso
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    melviso polycounter lvl 10
    Thanks a lot,again.You have really helped me a lot.I think I might go back to mudbox or better yet use ZBrush for modeling and Mudbox for texturing.
    Thanks again.

    BTW,Xoliul 2.0 SHADER,does it work with maya 2011 or only 3dmax?
  • Ace-Angel
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    Ace-Angel polycounter lvl 12
    Mudbox isn't exactly bug free, so be warned. If you start texturing in Mudbox, then everything fine and nice.

    However, if like me, you Texture in PS/ZB and plan on continuing in Mudbox, you'll run into a whole slew of problems, such as it not exporting/importing PSD files correctly, not accepting symmetry UV's because they come for PS, spiking polies, etc.

    Also, I'm not a fan on how Mudbox chuggs big time when you're using a web-browser and have several 4K textures in the layers.

    X-Shader is only for Max, old legacy version are available for Maya.
  • melviso
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    melviso polycounter lvl 10
    One thing I dislike about Mudbox is how limited it is when it comes to creating props and clothing.There is nothing like extract mesh,remesh,and those features that eliminate the need for a core modeling software.Although using ZBrush has sort of given me an idea of how to extract mesh from an already existing mesh in Mudbox.
    Started playing around in it today.Just love the 3d space.

    About xshader.Thanks.I just hope those awesome guys release a version for Maya.I haven't used it before but after watching those videos.I think I would like to try it out.Its realtime.Does that mean it will work in the original viewport or in viewport 2.0?
  • melviso
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    melviso polycounter lvl 10
    Made a decision.I will be using ZBrush from now on even for texturing and retopology.I tried using the decimation master on my 3d model,reduced the polys to the minimum that could still keep the details and exported it as an obj file.Imported it in topogun,and there was this huge drag when I move the camera in the viewport so I decided to do the retopology in ZBrush which works awesome as I have no need to decimate the mesh and no drag.I will only be exporting the low res mesh after uvmapping and extracting normal map and ao map.I will also paint all the textures in ZBrush and check from time to time how they look in Maya and make the necessary adjustments in ZBrush.
    This is because neither Topogun or Mudbox cn handle the same level of polys like ZBrush.Guess all apps have their downsides but the one with the best features can be managed better.
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