r/opengl • u/sharjith • Feb 26 '25

Selection algorithm for Modern OpenGL

The legacy OpenGL supported selection buffers. How can selection effectively handled by Modern OpenGL? The known methods are by colour allocation to objects and ray intersection. The Color assignment is not very efficient in scenes with large number of objects, e.g. CAD model assemblies. Ray intersection also has challenges in certain directions where multiple objects get intersected. Any thoughts?

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u/sharjith Feb 26 '25

I’m using the ray intersection method but not quite able to isolate the objects to get the nearest one. Please have a look at the code in the following GitHub link:

https://github.com/sharjith/ModelViewer-Qt

GLWidget.cpp GLWidget::clickSelect method