Hi Hamid, so again I must caution you that this is a complex model and not at all a very good first model to attempt to learn how MoI works. You have to use quite a lot of more advanced techniques to build this kind of model.
But I have included here a version that I created, the model is in the attached JabulaniBall_3DM_model.zip file, and I've tried to show some of the stages in how the model was constructed, although there are quite a bunch of little details that will be difficult to describe well in a short time.
Here is some idea of the steps.
To start with I drew the 2D flat pattern of the panels, but I arranged them a little differently, so they were set up like this:
Then I used the Transform > Rotate > Rotate Axis command to pivot the outer pieces upwards along the edge they share with the center piece, kind of like swinging them on a hinge. This is the same technique used in the previous post for making a dodecahedron that Pilou posted above, see that for an animation and description of the technique:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2140.46
But basically the key thing is to create 2 vertical circles that will then give you an intersection point so you have a place to snap on to during the Rotate Axis command to give you the specific rotation angle that's needed for the pieces to exactly touch one another.
That's actually done just on one of each kind of piece, then others can be created by Transform > Array > Circular, since there is a symmetry to the pieces.
That then gives a kind of wireframe outline of the panels, which looks like this:
Then I found the center point of that by turning some of those polygon curves into planar faces by using Construct > Planar, and then drawing in lines from the center of the face along its face normal and finding where they intersected.
Then I drew a sphere from that center point, and projected the polygons on to it. This is one of the tricky parts, because to get the best results later on you want to just pick a couple of good pieces that don't have the seam edge of the sphere running through them, and then carefully replicate those 2 good pieces to the other spots, that's done again using Transform > Array > Circular for a few of them, and then using Transform > Orient to place the top and bottom ones.
That then gives an object made up of panels where each panel is a piece of a sphere like this:
Then I selected all those sphere fragments and thickened them into solids using Construct > Offset > Shell.
Then I rounded the edges of each of those thick pieces using Construct > Fillet, to get the final result:
But I would really encourage you to work on some more simple models initially to learn how MoI works instead of this one, this one forces you to use quite a variety of tools and also some of the more advanced tools right from the start.
Instead, to learn MoI try going over the video tutorials here:
http://moi3d.com/2.0/docs/tutorials.htm
Those show how to construct some more simple models so you can get more of a feel for how to use MoI for building models that are more like mechanical parts instead of things that involve more 3D wrapped patterns like the ball.
- Michael
