# Printable D20

Oct 1, 2011

### Thing Apps Enabled

Probably a dumb question, but did you need supports to 3D Print this?

Okay mr whosawhatsis, your solution is WRONG! i know it will make you annoyed, and here is the truth... your solution makes 156 vertices for a 20 vertex shape... check the results when it has written the icos. it is completely wonky. When you zoom close to an edge you will see alot of mismatched borders. I think it's perhaps related to the 31.75 angle for a start. Where did you get that figure? whatever it is, the rusult is not an actual icosahedron, so you have written your code on other pages and it's wrong... i do the same always. can you find a correct version?

I had a go with this: edge = asin(1/(2*sin(72))); which is 31.7175, it still gives 156 vertices.

technically speaking you are distributing loaded dice

Top level object is a 3D object:
Simple: yes
Vertices: 156
Halfedges: 468
Edges: 234
Halffacets: 160
Facets: 80
Volumes: 2

Hi who!
just a note you can add to the instructions
For the best result use the same top/bottom and shell thickness ;)

"there just isn't (currently?) an elegant way to generate numbers in OpenSCAD "

How elegant of a solution are you looking for? Once you have outline information encoded in a way you can consume, you could actually generate numbers directly from there. I don't think it would be practical computationally though.

I think the most elegant solution would be to take FreeType, ge
nerate bitmaps with 256 levels of gray, and use those as height maps. That's about as elegant as I'd expect from OpenScad.

IMO, an elegant solution should be one that can be stated very concisely. Openscad doesn't have a way to load font data from within itself, and the shapes of arabic numerals cannot be procedurally generated in any way that doesn't amount to painting with polygons.

The most elegant solution I thought of was actually the same one used by donb's "Happy Numbers 0.2" ( http://www.thingiverse.com/thing:8691http://www.thingiverse.com/thi... ), but I didn't want to put such high-poly characters on the little faces of the D20, and making my own OpenSCAD-compatible DXF out of the numbers turned out
to be more trouble than it's worth.

Happy Numbers 0.2
by donb

I see. Yes, there are two things I could see OpenScad doing. 1) give the ability to read from files. 2) Have fonts as a first class citizen. I'd love to be able to place a 3D character as easily as I place a cube. OpenScad, integrated with FreeType, should make this an interesting thing to do. It could either be done as bitmaps that are linear extruded, or something more interesting than that.

New version of OpenSCAD has text(). Just letting you know.

Yah. I installed the latest a few months back to check things out. Text(), and minkowski is finally useable, and dynamic arrays. It's certainly becoming more capable than it was 5 years ago.