How to generate this edge effect?

Hey guys,

I’m a beginner with OpenGL and GLSL. In an interesting paper I have found visualizations like this:


Can someone of you explain to me how I can create this effect, when I have e.g. a triangulated torus? That would be awesome!


You have to find the silhouette of the torus for the first image.

This seems to be exactly what I was looking for. Thank you bob