Light not bending through Glas - Vray NEXT for Rhino

Hi,
i wanted to simulate a light beam passing trough a Prism. I set up a Prism (closed polysurface) with a standard Vray Glas Material and an Vray Spotlight. I Couldnt make the light beam bend when it enters or exits the glas material, it just goes straight through. I played with every Material, Light and render option i can imagine for the past 4 hours but nothing would affect the light beam. My guess it must be the IOR or refraction settings and that there is simple solution i just can see at the moment.
Rhino 6 with Vray Next

What you try is more than rendering only, it’s a kind of physic simulation. Maybe it’s possible at V-Ray if you use photon caustic (CPU mode only). If not, other tools like Maxwell or Bella could help.

Found something for V-Ray:
https://forums.chaosgroup.com/forum/v-ray-for-3ds-max-forums/v-ray-for-3ds-max-problems/33038-vray-2-0-dispersion-and-volume-caustics

Hey Micha thanks for your reply! In this thread the light is already bend by the prism. My glas prism does nothing at all, even Planes or Glasboxes are not affecting the light or bend it.
Do you know how to use Photon caustic in CPU Mode?

It worked :slight_smile: Thanks for the hint with photon caustics in CPU mode. I enabled “Irradiance Map” as primary rays and disabled “Affect Shadows” in the Glas Material.

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