I got a riddle given by a friend.
How can I model a sphere inscribed in tetrahedron (i.e. a sphere tangent to all the faces) ? of course this have to be parametric (the goal is to find a "rule of thumb" for a relation between the volume of the tetrahedron and the radius of the sphere.)
At first I was like, "Ez", but one the tetrahedron made, I can't do the sphere.... I have try with a 3d sketch but it's was a failure.
How do you guys will do this kind of stuff ?