I would like to render an object as if mirrored but on its own world position and with a mirrored orientation being camera view dependant. Something like the billboarding but keeping the 3D shape and showing it mirrored. I don't want to change my current culling when rendering it as it will be during regular scene rendering. See the picture below for expected result. Thanks in advance for your help.
A solution to this is to precalculate on CPU DepthMin and DepthMax for the object in a constant buffer. I was already using it for sorting the object back to front for some needs. Then apply some local transform to the object (if the mesh origin is 0,0,0) before the WVP operation and use the result to have a specific Depth. Then do Depth = DepthMax+DepthMin-Depth to "revert locally" the depth. With this equation when Depth = DepthMax it becomes DepthMin and vice versa all over the [DMax,DMin] interval.
I'm using this "revert" depth as fallback for hard case ray miss in SSR with some nice results to be improved. Using this method pixels from front faces difficult to hit can be found. I'm now twiking this to have the additional transform begin oriented according to the direction of the camerapos to objectpos to have a result consistant all over the screen. Like the billboard I was mentioning.