In Mathematica 12, the line of code below plots a torus in Graphics3D[] using ResourceFunction["Torus"]. It was plotted with Opacity[.2]. I was very surprised to see a sphere inscribed in the torus at approximately $\phi = 3\pi/2$ where $\phi$ is the angle of the outer radius. I take it this is some artifact of the BSpline function used by the “Torus” resource. Is there a mathematical reason for it, and is there any way to get rid of the inner sphere?
Graphics3D[{Opacity[.2], ResourceFunction["Torus"][{0, 0, 0}, {20, 2}]},Boxed->False]
