Caustics and GPU

[lorenzo_spinola]

Hi everyone,
because I'm starting to study Phoenix FD and the liquids for the moment.
I was wondering if it was possible to set up caustics on vray5 gpu.

I had a look arround, not many info founded but I found that caustics are working and set on by default, but photomap and render elements are not available for gpu.

being set on by default, I tried some tests....tests work in cpu mode pretty easily, switching to gpu nothing works......

so, are they really supported in gpu mode?
if yes, how can we set them up?
if not, are they going to be implemented?
Is it possible to do at least a light projection? similar to the fstorm ones to make an example?

right now I'm on the monthly subscription of vray because I'm thinking to switch to it from other render engines....I saw the list of NOT compatible features and I'm not so sure anymore though

Thanks in advance,
Lorenzo

[im.thatoneguy]

I also was looking for guidance on this. More specifically, is it possible to support path traced caustics using brute force GI? Photon mapping caustics doesn't work for me in my situation since I'm trying to simulate a fringe physical effect.

[nikoleta.garkova]

Hi guys,

Photon Caustics are not supported on the GPU - those are the ones enabled in the 'caustics' rollout. Respectively, the Caustics Render Element is for the photon caustics, and is also not supported.
What you can do for the time being is render on CPU and use them in comp.

I will, however, make a note in our Wishlist section in regards to both your queries for our devs to have a look.

[lorenzo_spinola]

Hi Nikoleta,
thanks for adding this to the whislist.
not that I'm usign caustics everyday in every project, but you know, in the view of using Phoenix more often....caustics would give a better results.

Using a cpu is a work around, ok....on a still frame can be feasable, on an animation though, I'm going to lose all the advantage I have with the gpus in terms of time.
Just frustrating that everything I'm trying out is not working with gpus

Just for asking, do you think you'll be able to close the gap between cpu and gpu at some point?
I know it requires a lot of development, I don't mean to rush anyone....
but you know, if gpus it's gonna be always an "LT" version of vray cpu, even if I have 3x 2080ti I'm gonna plan maybe to switch back to cpu in the near future with a threadripper f.i

Thanks for your reply,
Lorenzo

[squintnic]

Is it possible to enable caustics on GPU - i belive this is a bug. I swear evert time I start a project on vray GPU im forced back to the relative slowness of CPU

[Karol.Osinski]

Hi squintnic , just out of curiosity. What makes you to switch to CPU most often? What types of scenes you are mostly working on?

I am sorry, I surely seen couple of your projects but I can't remember what was it.