I would like to draw a torus, like the one on the question How to draw a torus, with a 3d package. I would like to avoid drawing the torus in 2d with inkscape (or directly with tikz) because I will need to add other elements (like, say, in 3D helix torus with hidden lines, and view them from different points of view.
However, the resulting figure is to be printed (in black and white, etc.), so I want to use only contour figure, instead of shiny, color-shaded pictures like the ones in 3D helix torus with hidden lines.
In the end, I would like to have something like that (but this one was drawn in 2d with tikz)
So I tried to use asymptote, and, well, with
import solids; settings.render=0; settings.prc=false; size(12cm,0); currentprojection=orthographic(0,20,10); real R=3, a=0.8, d=R+2a; revolution tore=revolution(shift(R*X)*Circle(O,a,Y,32),Z); draw(tore.silhouette(),black);
i get something like that :
So is there a method to do that without the hideous bug ?
I tried to do it with asymptote, but something else (tikz, sketch, black magic, etc.) would be fine, at least if it gives a vector output. However, I'm not interested in directly drawing the result in 2d (and it has already been done in How to draw a torus).
Thanks in advance.