Odd Issue With 3d Tools

Discussion in 'Design and Modeling' started by KaosLostOne, Sep 18, 2018.

  1. KaosLostOne
    KaosLostOne Member
    I have a odd issue with the 3D Tools feature. 3D Tools is claiming that I have loose shells but it is not showing anything out side of the model itself when I use the tool. Sometimes when I run it through netfabb and do a default repair the loose shell issue goes away but when I update the model from doing a slight adjustment the issue will come back. Any suggestions?
    Loose Shells Issue.jpg
     
  2. crashtestdummy
    crashtestdummy Well-Known Member
    Might want to remap the model in a fresh StL file. Since the error comes back I suspect you do have a loose shell someplace.
     
  3. stonysmith
    stonysmith Well-Known Member Moderator
    I've seen a number of times where there is a very tiny shell far from the origin. If you wish, send me the file via PM and I'll take a look.
     
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  4. stonysmith
    stonysmith Well-Known Member Moderator
    <File sent and returned>
    The problem was with a "kneecap" that was loose by a microscopic amount.
    Image1.jpg
     
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  5. stonysmith
    stonysmith Well-Known Member Moderator
    But... there is another problem with your mesh. Whatever method you're using to build the model(s), it is creating significant inner voids that may well cause Shapeways to reject the item. All of the inner items in blue below are voids inside of the mesh. Shapeways is likely to complain that "support material will be trapped" in these voids. Image2.jpg
     
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  6. KaosLostOne
    KaosLostOne Member
    Thank you. I will see about fixing the inner voids now.
     
  7. crashtestdummy
    crashtestdummy Well-Known Member
    looks like from Stony's work above your building your model from parts and joining them together. What I'd do is before resubmitting and going forward, remesh your model, If its watertight, the new mesh will eliminate all those hollow areas. I have no idea about the actual size but hollowing out maybe an option for a lager model to save cost, just make sure you add compliant escape holes, under the feet might be a workable location if it is free standing.
     
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  8. KaosLostOne
    KaosLostOne Member
    What is the best way of remeshing? I looked at using blenders function under modifiers however when I select a higher resolution "Octree Depth 10" I start to get various problems.
     
  9. stonysmith
    stonysmith Well-Known Member Moderator
    Unfortunately, I'm not sure that "simple" remeshing with most tools is going to work.
    The areas that I highlighted are connected to the exterior surface. Think of a cave with a VERY tiny opening.
    If the voids were independent or floating inside, then most remeshing tools would remove them, but these are different.
    Meshlab can resample the model, but in this case, it's going to make a mess of the exterior.
    I have repaired many such models with Blender, but it requires _hours_ of labor to do so.
     
  10. KaosLostOne
    KaosLostOne Member
    I am fine if it takes me hours to get a 3d printable item done, I am disabled with nothing of any importance to do, assembling the ones that I have been able to do so has been fun really but I want to know more about making a successful model.

    Stonysmith, what program did you use to show the outside of the shell like that, to show the voids in the model? I thought maybe netfabb but at least the free version that I can tell does not allow a cross section like that.
     
  11. kaadesign
    kaadesign Well-Known Member
  12. crashtestdummy
    crashtestdummy Well-Known Member
    I use Fusion 360, the free home use version to look at cross sections as well as all my CAD work.
     
  13. designsoul
    designsoul Well-Known Member
    Meshlab will let you separate all inverted shells (the voids) and remove them, but you end up with a solid model.
    You also do not want to run many steps - a cleaner mesh results from fewer steps in your workflow.

    If this is any good of a tip - when I model a figurine I do reinforce it with intersecting planes on the inside, but I also model a wireframe model running through the entire figure, coming out at the sole of the foot. With the thickness of the minimum escape hole, you simply boolean it out in the end.
     
  14. KaosLostOne
    KaosLostOne Member
    Yea, like that. Looking back at my current model I can see even after my attempt at a clean up I still left a large amount of stuff hanging around that should be removed. More motivation to do better.

    Thanks! I am going to look into it!

    I thought about using as I have read it about it being used in a few other threads. I downloaded and installed it but it set off a alert on malwarebytes when I tried running it, I know some programs and interfere with various programs like that.