Capturing the 'z-depth' of reflected objects on the reflecting surface for an AOV

[Matthew_Hicks]

Hi everyone,

Is there a way to get the distance (/ray length?) between the reflected object and the reflecting surface on the reflecting surface?

I've got a complex environment that's going to be composited using z-depth and/or deep. Reflections of that environment will need a similar Comp treatment, and I'm trying to avoid reflection cam / cards hackery if I can. This seems like a prime candidate for an AOV.

Reflection color information is resolved monte-carlo style, my thinking might be possible to similarly resolve the length of the ray between the reflected geo and the reflective surface. My guess is it'll need some kind of custom shader, but I'm not sure if this has already been looked at, or where to start.

Katana 3.2v3, KtoA 2.4.0.5, Arnold 5.4.0.2

Thanks very much for the help!