Hi I was googling all night and still dont know how to do this. I want to use C# motion mouse class, to catch x,y coordinates and use them in my opengl scene. 1 idea was to set ortho scene and draw my own cursor. But it works only with 2D scene ;) How to check what are x,y,z coordinates of the selected pixel ? I d checked many examples, but still doesnet work. I use C# and TAO framework. Plz give some advice.

Google for "3D picking"

You can convert your mouse co-ordinates to world co-ordinates using gluUnProject.



Just make sure you invert your mouse Y coordinates since .NET measures from the top left of the screen, but gluUnProject is from the bottom right.

x1, y1, z1 will contain where you've clicked in 3D space given a mouse depth of zero. You can call this method twice with a mouse depth of 1 to get a ray that you can use for things like collision tests.