I have a qt gui interface with an opengl widget.
I can draw disks(2d circular mesh) and lines, my problem is the picking.
1)how i can create a ray with a direction from the mouse for the picking?
2)How i can test the intersection of a ray with a disks and with a lines?
3)how i can transform the ray from the 2d view to model view?(is sufficent multiply for the inverse(in my case the transposed ) of the modelview matrix?