I ask my question again…
Depth value is scaled from 0.0 to 1.0
Is it right???
Then what does zero correspond to???
And what does one correspond to???
In the case of parallel projection
(orthonormal projection)…
Plz…
0.0 corresponds to the near clipping plane, 1.0 corresponds to the far clipping plane.
But the depth values are changed
as the view points(gluLookAt)are different…
Why???
What is the relation between
view point and depth value
in the parallel projection?
0.0 is a point on the near plane, and 1.0 is a point on the far plane, just as Humus said. It doesn’t matter what kind of projection you use, or how you called gluLookAt. The depthvalue is normalized after both modelview- and projectionmultiplications.