The first, and last, condline in a cyli have a controlpoint on the tangential plane to the cylinder.
When 2 cyli primitives are placed next to each other these condlines will complement each other.
This also explains why an author have to add an extra complementary condline if a surface is not placed in the tangential plane.
When 2 cyli primitives are placed next to each other these condlines will complement each other.
This also explains why an author have to add an extra complementary condline if a surface is not placed in the tangential plane.