following below post
here is the model of Icosahedral geodesic polyhedron class2.
the logic is to create a grid of points (mesh) on the 20 faces that connect the centers of the class1 base face mesh.
Then from this base mesh I keep only the full equilateral triangles for the projection to the subsribed sphere by measuring their area, keeping the max.
then using Convex Hull function, I create the base mesh for the geode.
What is the difference between Class1 and Class2?
it is the way the "pentagons" around the peak of the icosahedron are pointing to each others, this influence greatly the overall perception of the geode.
see below picture. on the left is CLASS1, on the right is CLASS2
here is the 3dxml, including the graph on how I could colorize with gradation.
