I got the realtime ring reflection working!



It is a screen-space reflection approach, for which I directly compute the screen-space coordinates, so that I get pixel perfect reflections without distortions. I do this by rendering first only the mirrored meshes, flipped along the mirror plane and printing the screen-space UV's of the non-flipped mesh.

Then I render the whole scene and add the mirrored pixels in a postprocessing step + FXAA.

I fade out the mirrored pixels by their distance to the mirror plane, by a fresnel term between surface normal and view normal and the distance of the mirrored pixel to the viewport borders.