Wall thickness issue

Discussion in 'General Discussion' started by maulik, May 14, 2013.

  1. maulik
    maulik New Member
    Hello guys.
    I am basically a modeler and sculptor and now I have to make some models for 3d print. I am using 3ds max for modeling and zbrush for detailed sculpting.

    Now, my problem is wall thickness. I have make model in 3ds max as per required measurement and now I need to add SHELL modifier to add thickness to wall. But I am not able to do it properly as its uneven. Its thin somewhere and thick somewhere instead of exact 1.2 mm shell that I add. So each time I am getting error from 3d print service that this model has lower wall thickness than required (I checked wall thickness and mesh compatibility with netfabb). I am really stuck in it and have tried to make it in zbrush too but failed... :(

    I would really appreciate if someone tell me the right pipeline to make proper way to make models ready for 3d print. I don't mind if I need to learn a new sw for it but I need a solid solution for it.

    Please help me out. I am attaching the sculpt that I did using 3ds max and zbrush. I want 1-1.2 mm wall thickness throughout this model.
    Hoping for solution from you guys soon.
    Thank you.
     

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  2. lensman
    lensman Well-Known Member
    Hi Maulik, I feel your pain... not sure if this will help with your existing model or, it depends on how much work you want to do. However, my pipeline for this model, from scratch, would be this: Basic shape modeling in Rhino (you use 3Ds Max which is okay, too, obviously). Bring OBJ into Zbrush. Divide a few times (not too much). Now turn this into a Dynamesh at default 128 level. Model the organic shape until you get to the point where all you need to add are details. Use Insert Sphere tool and insert a sphere (holding ALT key) to unobtrusive spot (on belly?) then re-Dynamesh using Shell button with appropriate shell thickness - this has to be guessed at initially. Once you get the hollowed out model I would suggest exporting as an OBJ and then importing into NetFabb where you can measure the shell thickness. Too thick or thin? Go back to ZBrush, do a Ctrl-Z and re-do Shelling.

    Once you have the hollowed model to the thickness you want, NOW you can start doing your detail modeling and texturing.

    Sorry, I don't have ZBrush in front of me so I hope I have used the correct terminology there.

    The beauty of doing this with Zbrush is this: Where the model is thin (i.e the tail in your model) then it won't be hollowed. Only the thicker parts get geometry removed.



     
  3. UniverseBecoming
    UniverseBecoming Well-Known Member
    Are you wanting to print this in Full Color Sandstone? Because if you are the minimum wall thickness for that material is 2 mm for your supported walls.

    Yeah, it's difficult to get a nice even thickness using polygonal software. The best I've found so far for doing this is Blender using the solidify command, that is unless you can afford something like Geomagic. Max's shell would probably do just as good as Blenders solidify, but I haven't compared the two. I know that Blender has a means for compensating for sharp corners and whatnot, but I've never compared Max to Blender. One thing I do after using Zbush's dynamesh shell is to decimate way down and then use 3Dtool to do a wall thickness check like this,

    [​IMG]

    I then hand edit the high rez version back in Zbrush to compensate for any changes that I need to make. Once everything looks good I decimate the inner part of the shell way down so I can have more polygons for the outer part of the shell to handle the detail I want.
     
  4. stop4stuff
    stop4stuff Well-Known Member
    Even thickness is what MeshLab does with its Uniform Mesh Resampling function, have a search in the forums, step by step has been posted a few times. This and the mesh integrity checking needs to be done before any colouring though (same as unifying shells if there's more than one shell).

    Paul
    [hr][hr]
     
  5. UniverseBecoming
    UniverseBecoming Well-Known Member
    Bringing up Meshlab made me recall Meshup, which will, once development is completed, use voxels to obtain perfect shells for 3D printing.
     
  6. maulik
    maulik New Member
    Thank you lensman,
    I tried store morph target and create diff mesh but it dint work. I will check out this method too. I hope this will work. thanks for the advice..



    Thank you stop4stuff & UniverseBecoming,
    I will surely check out meshlab for it. I am pretty good at zbrush but my knowledge in 3d printing is almost zero. Thank you guys again for such quick and in depth reply. I really appreciate this. :)
     
    Last edited: May 15, 2013