when get the intersection curve of a cylinder and tous, I found a bug ,the intersection curve is not right.

TorusCylindrical.3dm (204.6 KB)

It’s not a bug. It has to do with the definition of your geometry. Rebuilding helps.

TorusCylindrical.3dm (494.6 KB)

tks for reply， from your picture I find the tangent circle curve is missing. It is the right behavior ?