How to get data from rendered objects on screen

[downybear]

Hi all,
I am brand new here, so my question is probably very simple, but I can't find anything what I need - probably bad queries in Google and here .
I am using OpenGL with Delphi.
I am experienced programmer but not in OpenGL.

Using examples I did 3D display of the physical values using HeightFields and small Cylinders, Cones and Spheres as a children of the HeightField.
I need a hint, how to get values of the X,Y,Z position of the objects under the mouse.

Thank you for help.
Regards
Mariusz

[BionicBytes]

try a Google on gluUnproject

[downybear]

Hi,
Thanks a lot BionicBytes.

Good query is the key

It works already.
This particular answer for Delphi users is here:
http://www.sulaco.co.za/using_gluUnproject_tutorial.htm
and many, many more.

Of course - I was there many times, but I didn't knew magic word "gluUnproject".
Best Regards
Mariusz