Thanks everybody!
I only need some really basic picking, ie the intersection with the y panel.
I think Sly function may help.. if i have the line that's beneath the mouse, i can do a line/plane intersection.
The problem is that that function is not so clear without the called functions
For example the how the BG_GetFov work ? and the BG_WorldPoint ?
Also, where the nearPlane and farPlane came from ?

Thanks