I kind of understand the basics of using shaders on geometry/models, but I haven’t been able to figure out how to go about using shaders for postprocessing effects, applied to the camera or the screen.
For example, how can I apply this Fisheye effect to the camera? https://www.geeks3d.com/20140213/glsl-shader-library-fish-eye-and-dome-and-barrel-distortion-post-processing-filters/
thanks