Hi
I’m trying to find out what different light patterns I can create with different lenses, but no matter what shape I place in front of the light it doesn’t seem to have any effect on the light rays passing through it? Ie when I place a flat surface in front of the light, the light projection on the surface is the same no matter what differently shaped lens I place between the light and surface?
I’ve attached some images (along with material, light and render settings) to explain better.
can you show some real photo reference , I want to understand what’s your goal.
By the way, I guess you should start creating a physically correct material, and probably activate caustics to obtain the result you want.. but fist show me a real photo reference.
Caustic enabled are definitely needed for this kind goal. Some tutorials should be available at the web.
Never I really used caustic, but I would take a spot light so that the photons are more focused. Than maybe it helps to shoot more caustic photons.
But … I can’t find the global caustic option anymore. Maybe it get lost. I can find GI caustic only, but this isn’t needed here. I hope the Chaosgroup team will help.
Unfortunately the issue happens with every kind of light I put into the scene. In this one I used the rectangular with a directionality of 1 since it won’t scatter no matter how far away the surface is from it - ie the only scattering should come from the light passing through the lens.
I’ve found a slightly different tutorial here https://www.youtube.com/watch?v=\_5zW0jyLa3c&ab\_channel=GiancarloDiMarco that I’m working through, hopefully the answer is somewhere in it.
I’ll make sure to post the solution if I find it!
Did you find the global caustic control? If not, a workaround could be to save the v-Ray option and look for the option per text editor. So, I hope, you can enable it.
I found the photon caustic options now too. 
Did you disabled “affect shadows” at the refraction layer of the glass (you need to enable the advanced options of the glass)? It’s needed for photon caustic and GI caustic.
I tested the photon cautsic and it works at default values, only I need to increase the spot light intensity.
Page refreshed just when I uploaded, sorry didn’t see your reply there!
I suppose so the color effects are caused by the dispersion. I used a quite high value since I hoped to see an effect. Maybe it’s to much for your scene, you can disable dispersion also.
Wow, nice example, good to know.
