Posted by Irene Tang on Mar 03, 2016; 10:27am
URL: https://forum.jogamp.org/Why-is-the-z-value-read-from-glReadPixels-always-1-0-tp4036395p4036415.html

I don't understand what you said. I think the reason might be that nothing ever rendered in the clicking point, so the z-depth would be the default 1.0.