- DrawDroite( <line> [, length L1, length L2] )
- Description: draw a line of the space, written in the form: [3Dpoint, 3D direction vector]. If there is no other argument, then the line is entirely drawn. If there are two other parameters: <L1> and <L2>, then if $A$ is the point and $u$ the direction vector, this is the segment joining A-L1*u/norm(u) to A+L2*u/norm(u) that is drawn.