Re: [PyOpenGL-Users] gluUnProject Projection Failed

[Greg E. <gre...@ca...>]

Eleftherios Garyfallidis wrote:

>             wx,wy,wz= glu.gluUnProject(float(x),viewport[3]-float(y),0.,
>                                               modelviewmatrix,
>                                               projectionmatrix,
>                                               viewport)

I don't think that 0 is a valid value for the z coordinate
when you're unprojecting in a perspective projection.

Also, to get a ray, you need to know *two* points in the scene.
The way I do it is to call gluUnProject twice, once with
z = the near plane, and once with z = the far plane. A line
between the two resulting points gives you your pick ray.

-- 
Greg