3D CAD software

Discussion in 'General Discussion' started by Orangery, Nov 19, 2010.

  1. Orangery
    Orangery New Member
    I'm new to this. I'd like to know what 3D CAD software people are using for dice and other polyhedra.

     
  2. aeron203
    aeron203 New Member
    I don't make dice, but I can tell you that for creating objects with polyhedral symmetries, you will probably want to use a topological modeler. These are programs that make it easier to perform the same action on different faces of the polyhedron simultaneously, si that your dice will be well balanced. One popular free program is TopMod, which has some unique and powerful tools, but I favor one called Wings3D because it includes many of the features you find in full-featured editors like Blender that are very powerful but have a steep learning curve.

    Wings3D can automatically generate polyhedral primitives for you to start with and it has a very intuitive interface. It is free, of course.

    http://www.wings3d.com/

    http://code.google.com/p/topmod/

    You may want to get into Blender when you get a little more experienced - Blender.org
     
  3. mctrivia
    mctrivia New Member
    I use Alibre to design all my dice. Only $100 but it does have strange bugs that can be frustrating at times.

    You can draw a rough sketch then put numbers or equations to how large each dimension should be. Also has a feature to compute the center of gravity which is essential if you want a die that is properly weighted like all my dice are.

    If you are a student you can get a copy of Solid Works for $100 otherwise it is $5000. It is an impressive software package and I may consider switch next time I am back in school.
     
  4. Orangery
    Orangery New Member
    Thanks for the info. Someone else suggested Google Sketchup which has some decent tutorials. I'll also take a look at Wings3D.
     
  5. dizingof
    dizingof New Member
    With Google Sketchup you have a feature called "component" which basically is what aeron203 described -
    "perform the same action on different faces of the polyhedron simultaneously"

    You edit one and changes are made through all copies in real time.

    With this feature a model like this can be made :
    http://www.shapeways.com/model/149198/knot_pendant.html?gid= sg28396

     
  6. Orangery
    Orangery New Member
  7. clsn
    clsn Well-Known Member
  8. Orangery
    Orangery New Member
    Thanks for the link (looks great) but I am having problems viewing the files. I first installed CosmoPlayer but it didn't allow me to open any of the .wrl files. I then tried something called FreeWRL which displayed the example .wrl file for a split second then vanished. What am I doing wrong?
     
  9. clsn
    clsn Well-Known Member
    Not sure what if anything you're doing wrong. Some 3D software needs to "import" VRML instead of just opening it; you might try that if there's an option in your menus.
     
  10. dizingof
    dizingof New Member
    you need to install cortona3d plugin for your browser then you'll see the models and rotate them, zoom etc..

     
  11. aeron203
    aeron203 New Member
    The best VRML viewer I've found is called View3Dscene, a.k.a. the Kambi VRML viewer ( http://vrmlengine.sourceforge.net/ ). They just released a new version and it works great. No browser integration, but no installation needed either (portable).

    Oh, and about Blender...
    I noticed the link was dead and wondered why. [EDIT - Blender.org is back up after being inaccessible for some reason. I don't know what was going on but I did send Bart an Email about it (he is very active in the Blender community).]
    Other than Sketchup+plugins or Wings3D, there is a pretty good app called K-3D ( http://www.k-3d.org/ ) that has quite a bit of potential.

    I also forgot to mention Meshlab ( http://meshlab.sourceforge.net/ ), an essential tool for file conversion and other basic 3D work.
     
    Last edited: Nov 22, 2010
  12. Orangery
    Orangery New Member
    Thanks for your help aeron.

    I might persevere with Google Sketchup for the models. I am now trying to modify archimedean solids so that the faces are circles instead of polygons. Does anyone know how to do this? The idea is to round off the edges to form special spherical dice.
     
  13. Magic
    Magic Well-Known Member
    The easier way is probably to make the intersection between a sphere and your archimedean solid.
    For example this rounded dice is the intersection between a cube (the 6 flat surfaces) and a sphere (the round surface). Of course, you will have to choose the radius of your sphere carefully so that it is big enough to remove the edges of the solid and small enough to still show the faces of the solid.
    Doing a sphere is sketchup not the easiest thing though, unless Dizingof has one secret plugin to do so... :D
     
  14. dizingof
    dizingof New Member
    Why secrete? i keep posting links to Sketchup and plugins for sketchup as if i'm on Google's payroll :D

    Sphere is easy.. there's an app for that ehhh.. script.

    Check out my 125 Dice designs - you can see what can be done with Sketchup.

     
  15. Orangery
    Orangery New Member
    Magic, I'm using polyhedrons with more faces (actually 32). I'm still learning Sketchup basics.

    Dizingof, those dice are pretty impressive and so many. The parachute dice are cute.

    There are various example models I can use for my project as a starting point. I just need to somehow incorporate the circular sides. Can you help me on this?
     
  16. dizingof
    dizingof New Member
    basically to round a mesh you need the right pluging installed - go over the link i posted above and install the essential plugins

    you can post here pics or skp or stl file and if i can help i will.

     
  17. Magic
    Magic Well-Known Member
    @Dizingof: Sorry, by "secret" I was meaning "unknown to me " ;)
    I've seen that there are different plugins that allow you to make sphere like the Superellipsoid 1.0 but the simplest is probably the Sphere 1.1

    @Orangery: in effect this method works for all 5 regular polyhedra but also for the cuboctahedron and icosidodecahedron (32 faces). In fact, I guess it works for any polyhedron that has any of its edges at equal distance for its center.But it does not work necessarly for more complex shapes (for the soccer ball, 32 faces also, for instance, the circles inside the pentagons do not touch the ones inside the hexagons) .

    [EDIT] fixed some errors about the soccer ball
     
    Last edited: Nov 25, 2010
  18. Orangery
    Orangery New Member
    It is the soccer ball that I wanted to modify. This link http://i1138.photobucket.com/albums/n536/the-orangery/buckyb allnet.png should take you to a rather crude drawing of what the net might look like. As you can see all circles (faces) are the same diameter, its size governed by the pentagon. All sharp straight line edges should be rounded off so it is more like a ball shape.

    Dizingof - I went to the 'plugins for sketchup' link but there doesn't seem to be any way of searching for stuff.

    Magic- I have downloaded the both the sphere links but it hasn't really helped me that much yet.
     
  19. dizingof
    dizingof New Member

    you mean like this?
    http://www.shapeways.com/model/165998/circles_d8_dice.html?g id=sg28396

    you don't need to search, thou you can. simply enter the plugins thread and install the essentials ones
    http://forums.sketchucation.com/viewtopic.php?f=323&t=16 909&sid=1c4871911c47975be4fd989cdbeb85f8


     
  20. Magic
    Magic Well-Known Member
    You have to think in 3D. Basically, what you want is a sphere with round faces of the same diameter arranged as the faces of a soccer ball.
    If I was in your shoes, my first idea would be to take a sphere, intersect it with first an icosahedron and then with a dodecahedron (ordre is not relevant).
    There are 3 unknown: the radius of the sphere, the radius of the icosahedron, the radius of the dodecahedron.
    Actually only 2 because you can always change the scale of the whole model.

    But to get the same diameter for all the circles, the distance from the center to the face of the dodecaedron, must be the same as the distance from center to the face of the icosahedron.
    This gives you a relashionship between the radius of the dodecahedron and the radius of the icosahedron.

    Most of the tools work with the radius of the circumscribed sphere (that is the distance from the center to the vertices) that I will call Rv. But what we need is the distance to the face (the radius of the incribed sphere Rf.
    Let's do some maths:
    for a icosahedron
    - Rv20=0.951a (a is the side of the icosahedon, but we don't care)
    - Rf20=0.756a
    so Rv20/Rf20=1.258 (no more a)
    For a dodecahedron
    - Rv12=1.401b
    - Rf12=1.114b
    so Rv12/Rf12=1.258 (no more b)... The same value. Coincidence? Probably not.

    As we stated that we wanted Rf20=Rf12, it means that Rv20=Rv12 (very long computation for a very simple result, indeed).

    So if you take one dedecaheron and one icosahedron of same radius (do they intersect into a regular soccer ball?*), and then take a sphere of the same center and make the sphere grow until you see it appearing through the 32 faces and go on growing it before the circles overlap, you should get the correct radius for the sphere.
    Then, make some boolean operations to keep the part of the sphere that is inside the dodecahedron and the part of the resulting shape that is inside the icosahedron (in Sketch Up, I think you just have to make the intersection of the three, and then remove manually the useless part of spheres).

    Hope this helps.

    EDIT: *do they intersect into a regular soccer ball?
    The answer is no (see the render below). The hexagons are not regular. Each hexagon is surrounded by 3 hexagons and 3 pentagons and each pentagon is surrounded by 5 hexagons. The fact that the hexagons are not regular allows the circle inside this kind of hexagon to have a contact with the circles included into the 3 surrounding regular pentagons (but not the circles of the 3 surrounding hexagons), and each circle included into the regular pentagon will touch all five circles of the surrounding irregular hexagons. This was not the case in the original pattern (no contact). We can bet that this shape illustrates the best packing of 32 identical circles onto a sphere.
     
    Last edited: Nov 28, 2010