Stupid Question : Case Building Development

Discussion in 'General Discussion' started by randomblink, Feb 21, 2013.

  1. randomblink
    randomblink New Member
    I'm getting closer and closer to uploading and ordering an actual object... still not there (and with a newborn in the house, it might be a couple more months) but I had a question...

    I am confused as to how you would create a case for something that you have dimensions or a 3D model for.

    I am assuming the following...

    [list type=1]
    [*] Take/Build 3D object of item you are making case for
    [*] Expand the object by roughly 1mm in every direction, of every surface.
    [*] Now put THAT expanded object INSIDE of an object roughly the size the finished case you want
    [*] Shape the case object
    [*] Make sure the finished case has minimum wall thicknesses
    [*] Delete the expanded object inside of the case
    [*] Clean up and voila! Finished case 3D model is done
    [/list]

    I know this is an EXTREMELY simplistic process, but I am just trying to make sure I understand the basics.
    My question is... is this a working example of how you could design a case?
    Are there better examples? Video tutorials? Help?

     
  2. JACANT
    JACANT Well-Known Member
    These tutorials will help you understand what is required.
    http://www.shapeways.com/tutorials/
    Each software has it's own way of making a model hollow.
    Blender uses a modifier called 'Solidify' which creates an inner 'skin', an input distance from the outer shell.
    Autocad uses a command called 'shell' which does the same thing, by asking what the 'wall thickness' should be.
    In each case a hole or tunnel has to be made to join the inside to the outside, otherwise Shapeways software will ignore all internal walls and treat the model as solid
     
  3. randomblink
    randomblink New Member
    I understand the hollow process, I've dabbled (just enough) and know about hollowing out an object.
    My problem is... in the instance of an iPhone case (for example) if I create a case and hollow it out automatically, it won't fit snug on the iPhone. There will be gaps and such.

    If I want to make sure it fits, I would put the iPhone model inside of my finished case and CUT that size/shape of material OUT OF the Case object.

    But it feels like this would still not fit, or work. I am hoping that someone who has designed a case like this could just verify with a 'Yeah, I do something like that...' or 'here's a video tutorial of how I do it.'
     
  4. stop4stuff
    stop4stuff Well-Known Member
    Use MeshLab.

    Load up your object.
    Click on the Filters tab--> Remeshing simplification.. --> Uniform mesh resampling
    Set the Precision parameter to something smaller than the thickness difference you need (or the the size you need for the triangles to ensure a good print quality).
    Set the offset value to the thickness differenece you need.

    Save the resulting 'offset mesh' and chop it up as you see fit :)

    Paul
    [hr][hr]
     
  5. UniverseBecoming
    UniverseBecoming Well-Known Member
    Yeah I thought you were referring to making a hollow shell too from reading your original description. CASE! As in an actual CASE! I see now! :D

    You're right, when you extend those surfaces it's not going to be perfect if you're using a polygonal modeler. If using a parametric solid modeler or direct solid modeler it may be more exact, but still if you want it to be absolutely perfect what you would do is model the object you're making a case for with the 1 mm offset designed in. At that point then you would design the case and do the boolean subtraction. Or, since you can run into problems when doing boolean operations, just design the case to be how you want it using your original object as a guide and avoid having to do booleans all together.

    That's for absolutely perfect though. If just designing a phone case and not space shuttle parts, I would just go ahead and use the method you originally described. Unless your original object is super complex you shouldn't have a problem doing it in that way.
     
  6. UniverseBecoming
    UniverseBecoming Well-Known Member
    I'll have to try this some time! I know Meshlab can do some pretty amazing stuff so I'm anxious to try this out. :eek:
     
  7. JACANT
    JACANT Well-Known Member
  8. stop4stuff
    stop4stuff Well-Known Member
    Blinkin' 'eck.

    Now I'm confuddled.

    Let;s recap.

    I have an object as a 3D model.
    I want to create another object that fits around the first object.

    How?

    That's how I understood it.
    (soz if I got it wrong)

    Paul
     
  9. JACANT
    JACANT Well-Known Member
    I thought he wanted an iphone case

    QUOTE
    My problem is... in the instance of an iPhone case (for example) if I create a case and hollow it out automatically, it won't fit snug on the iPhone. There will be gaps and such.

    If I want to make sure it fits, I would put the iPhone model inside of my finished case and CUT that size/shape of material OUT OF the Case object.
     
  10. stop4stuff
    stop4stuff Well-Known Member
    I saw 'for example' and ignored the object. :confused

     
  11. randomblink
    randomblink New Member
    Thank you all...
    I knew I was overthinking it or making it more difficult that it needs to be. Sweet...