# Sphere with equally sized triangles

I think this is called a "geodesic sphere", is that right?

Does anyone have an algorithm/code that creates one? I simply need I sphere with equally sized tiles. I can't think of any other geometry but a geodesic sphere. The triangles are supposed to be equal in size when looking straight down on the sphere (planetary object). I will add any height/depth information (hills, mountains, …) to offset the vertices from/to the center of the sphere in an additional step later… Does anyone have code for this? C/C++ would be fine too.

Is it right the base object for such a geometry is a dodecahedron, that is, 5 triangles form a complete fan, not 4, not 6…?

Maybe someone has an algorithm/code to create a dodecahedron easily? I would then tile each triangle with 4 or 9 triangles and offset the resulting subvertices accordingly.

I bet this is standard code…

Ahm, BTW: Wouldn't this be a nice extension for a future jME?

-> new Dodecahedron and new GeodesicSphere classes… I bet there are many situations, where game developers need a sphere with equally sized triangles… -> Planets etc…

Karsten

Yes, this is called Geosphere in max. I posted about it here. But I didn’t know how texture coordinates should be mapped… if you can tell how this should happen I will happily add a geosphere to jME.

Hmm I might not be quite in the picture about it… Where's the difference between mapping a standard sphere and a geosphere?

You mean, because there is no actual axis you can calc the UV coords from?? :?

Yes, you could compute normal polar mapping coordinates for the geosphere (which is quite expensive, but acceptable as only for creating the mesh). But it looks really bad even worse than on a normal sphere :’(

Hi irrisor!

I followed the link you posted…

Where can I get the sources from? I can't see any download locations, neither your code nor Ogli's…

Can anyone tell me how to get them?

Karsten

I did not upload the code anywhere because I was still missing texture coordinates.

But I think I could simply add the GeoSphere to jME - probably with polar texture coordinates. Stay tuned (I hope to get it done tomorrow).

I have committed the GeoSphere with polar texture coordinates.

cool! good work!

little thing, any reason you put it in it's own package, spent time looking where I expected it to be

own package :? it's right besides Sphere, isn't it?

I mean the test sorry about that

Ah, well yes. The other simple shape tests (like Sphere) are spread over the 'renderer' and other packages. I think a new shape package was needed. Maybe there can go other such tests lateron.