Posted by scott+jogamp@vorthmann.org on Dec 31, 2019; 8:18pm
URL: https://forum.jogamp.org/questions-about-picking-tp4040211.html

First: you guys have my undying gratitude for your dedication to maintaining JOGL, etc.  My app (https://vzome.com) would have died many years ago without your hard work.  Harvey has been particularly helpful, and he even showcased vZome as a Java3d app once, I think at SIGGRAPH.

Now, I'm finally eliminating Java3d from vZome and using JOGL directly, and using it without the fixed function pipeline.  So far, the results are very gratifying, and I haven't even looked at the memory profiling yet.  All the easy stuff is done, but I have a few thorny tasks left.  The biggest one is to implement picking.

I've been digging around, looking for a reasonably straightforward sample.  I found Julien's SO post, which led me to this sample of Sven's, which is perfect in size and scope, but it uses the deprecated OpenGL built-in picking, and the fixed-function pipeline.

My hope is to modernize that sample; I have already forked java-demos.  I was able to build and run the picking demo on my Mac, but it has a defect at the moment: the picking seems to be using the wrong coordinates, so that the results don't match the mouse location.  QUESTION 1: Does anyone know if that demo works correctly on other platforms?

QUESTION 2: Does anyone have or know of a good demo of picking using FloatUtil.mapWinToRay or FloatUtil.makePick, or really any modern demo of picking with JOGL?

I hope to prove out picking in a sample, before I try to get it working in my more complicated application.  I'll be happy to "give back" and submit a pull request, if I'm successful.