Sphere <radius> <density>
This command creates a sphere of the given dimensions in the current clump. The sphere is transformed by the current transformation matrix and its surface is assigned the current material.
The density controls the number of polygons used to approximate the sphere. It cannot be negative. A density of 0 results in a cube. The number of polygons varies exponentially with the density.
The radius can be either positive or negative. It cannot be zero. A negative radius creates a sphere that is "inside out" (i.e. only visible from the inside).
<radius> the radius of sphere
<density> the density of the sphere