Slightly changed guide curve construction method
Slightly changed guide curve construction method

such that the gamma direction equals the normal to the ruled
surface.

codingpoets/tigl,DLR-SC/tigl,codingpoets/tigl,DLR-SC/tigl,codingpoets/tigl,codingpoets/tigl,codingpoets/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,codingpoets/tigl