Sorry for my English!
I found a description about the fastest reflection algorithm for flat surfaces. http://www.remi-genin.fr/blog/screen-space-plane-indexed-reflection-in-ghost-recon-wildlands
I want to recreate it in unity. Attached an example for testing https://www.drive.google.com/open?id=1WfgCpxwx8k6lgALHY6s_588p1D4lYEb6 I have some problems.
1) Why does the example use reflection along the Z axis? After all, the example is reflected on the horizontal surface Y?
2) In my implementation, an incorrect hash buffer.
Perhaps the buffer is written in reverse?
I added a z-buffer distance limit for test. You can see what's happen on 40/100/1000 meters.
Here is the contents of the hash buffer
I tried to change the interlocked Max / min, reversed the value of the z-buffer, tried without hashing (just write uv), still did not succeed.
3) Another interesting question is filling holes. The author writes this
Temporary reprojection for static images will not work (or am I mistaken?) And in the second part I did not understand what he was doing? Is it blending the previous frame and the current frame of the reprojection? ps There are a couple more links for this method, but the code is more complicated and confusing. http://www.guitarjawa.net/wordpress/wp-content/uploads/2018/04/IMPLEMENTATION-OF-OPTIMIZED-PIXEL-PROJECTEDREFLECTIONS-FOR-PLANAR-REFLECTORS.pdf http://www.advances.realtimerendering.com/s2017/PixelProjectedReflectionsAC_v_1.92.pdf