problems with gluUnproject

Hello,

iam using gluUnproject function to retrieve the object coordinates from the screen coordinates.

when i click on a point (2,2,2) i get the output from the function as(2.218335,2.226619,-0.000000)

when i click on a point (3,3,3) i get the output as (2.218335,2.226619,-0.000000)

when i click on a point (4,4,4) i get the output as
(3.079899,3.084041,-0.000000)

when i click on a point (5,5,5) i get the output as
(3.079899,3.084041,-0.000000)

why is there such a discrepancy in the actual values and the returned values of the function??

is it the nature of the function itself or there is some other problem with my code??

i want to retrieve atleast the x-coordinate more or less exactly??

plz help me ,may be with any other possible solution.

thanking you,
vamsee.

Hi !

If you use perspective mode then you need to handle the depth also, remember that you specify the Z value in gluUnproject, OpenGL can’t figure that one out on it’s own.

If you use orthographic mode you could map it to the correct X,Y coordinates.

Mikael

its not about the z value being 0.
its about discrepancy in the values of x and y coordinates.
i want atleast my x-coordinate to be retrieved more or less exactly to the object coordinates.

please help me out.