Generate a new capsule geometry, long axis aligned to local Y.
The radius of the capsule.
The height of the capsule including end caps. Must be at least 2 * radius.
The number of polar vertex rings (running the length of the capsule).
The number of equatorial vertex rings (not counting poles) per cap.
The amount of texture space the end caps should occupy.
An initial material to apply to the capsule.
A MeshPrimitive prepopulated with capsule vertices and triangles