Have you tried V-Ray (RT) GPU ?

[savage309]

Hey folks,

Just wanted to check how many of you have tried V-Ray (RT) GPU in V-Ray 3.5 or later?
If so, what hardware have you used, do you have dedicated GPU for monitor and has it worked for you in general?

If not - why? Was it startup time, render speed, UI, lack of features, interactivity, stability or something else?

Thanks,
Best,
Blago.

[infranea]

Hi

I gave it a try a while ago (before 3.5 update though) and I must say it was slower than CPU rendering on the workstation I had (i7-5930K cpu, GTX 970). Looks like its not for me. Probably it will be faster if I put second GPU in, but I'd rather use render farm that we already have.
Not sure if that helps, just my 2 cents.

[Undersky]

I tried it when the Hybrid renderer was introduced. Since then, I sometimes try it at the start of a project, but always end up going back to the regular V-Ray Adv. due to lack of features. For example, If I use EdgeTex to get lines in my renders, the lines are visible in the light cache pre-pass, but as soon as it starts rendering, the lines are gone.

I've also come across exposure inconsistencies between V-Ray Adv. and RT, where RT seemed to ignore the Exposure control. Could've just been a bug, but there are too many of these small things that stops me from using it.

I must also say that it's a bit unclear what name you use... In this post you call it "V-Ray GPU", but when switching to it in 3ds Max, it's called "V-Ray RT". And it has also been called "V-Ray Hybrid". So... which one is it? =)

My specs:

2 x Intel Xeon E5-1650 v4 @ 3.6 GHz
64 Gb ram
Nvidia Quadro M4000
Windows 7
3ds Max 2018.2 (as of today, earlier tests was with both 2017 and first iteration of 201
V-Ray 3.60.01

[kosso_olli]

I tried it a number of times, and I always come to the conclusion that our projects are way too big to be handled by the GPU.
To this day, I wasn't able to render an interior shot of a car, because it exceeds the RAM limit by a very wide margin. Also, I would be missing the VrScans, and I had problems using the Displacement on GPU. I had strange triangle artifacts, there is a thread about this somewhere. However, this was two releases ago, so things might have changed since then.

Just an idea: Wouldn't it make sense to send this out as a survey to all customers? I remember something similar being done with the VrScans shortly after release.

[vlado]

Just an idea: Wouldn't it make sense to send this out as a survey to all customers?

Yes, but we need to know what kind of choices (if any) to put in the survey.

Best regards,
Vlado

[BBB3]

Since you helped me debug my slow RT GPU scene the other day, I've been testing it in a number of older projects and I'm getting really good performance on one lonely 1080Ti. I can see myself using it more and more on simpler scenes and for animations.
Right now though, I'm hitting two big limitations:
1. Displacement. I can fit my entire garden scene on my GPU's 11GB, which actually was a huge surprise given the sheer amount of geometry and 4K maps all over the place, and it renders fast. But the scene just won't fit with displacement. With some serious optimization (replacing some displaced surfaced with retopoed meshes with normal maps for instance), I'm sure I could make it fit and get about the same final quality. But it would need starting the project in a different mindset, much like people might be going about building a scene intended for Unreal.
2. No glossy fresnel. This was one of the main leaps for me recently in terms of realism. Not having it on the GPU feels like taking a big step back.

[thanulee]

Hi, i have tested RT in many versions till now and im really willing to make it my main engine.
Unfortunately, the lack of features in our latest project couldnt let me actually see how it performs in some heavier scenes (missing Alshader which was key component in every shot). So one thing is that i d like 1:1 the features i use in VrayAdv + caustics.
Another thing i want to address is displacement. I experienced many crashes especially when i fiddle with displacement parameters real time, even in simple scenes. Same goes for hair (ornatrix tests). Missing stability, although renders really fast.
The most important thing that leads me back to Octane everytime when it comes to gpu, is the interactivity. I think Octane's interactivity in that matter should be an example of how real time should work. It feels so light and i can see stuff as i am moving em, while vray delays to update. Try it out and u ll see the difference
Besides these, overall i am really happy about the support i get and the updates from u guys and im sure our voices will be heard
Thanks!!

[BBB3]

Though Octane only supports changes to materials and lights in real time, right? Transforming geometry in any way, even a simple translate, forces you to manually refresh the viewport.

[thanulee]

Not sure about deformations, but if u set objects as movable proxies (in 3ds max) translations are real time. In c4d that i mostly utilise it, all is real time.
Octane has A LOT of bad stuff, but real time aint one of em

[BBB3]

Oh, ok. I'm referring to the Max plugin, which I guess isn't as well integrated as in C4D. There, anything that involves geometry (moving, deforming, hiding, revealing...) doesn't get reflected in the Octane viewport until you flush it.

[thanulee]

Have u tried using the movable proxy option? Its in octane properties and thats what it does. Havent used it in a while in max, but im quite positive it does transformations at least In any case, the optimal behavior is everything, thats why i mentioned c4d.

edit: check this out https://www.youtube.com/watch?v=31FvXIOxEVk

[BBB3]

Gotcha. Will check it out.

[vlado]

edit: check this out https://www.youtube.com/watch?v=31FvXIOxEVk

Try to do that with a) production shaders and b) deforming geometry

Best regards,
Vlado

[thanulee]

Dont get me wrong Vlado, i dont intend to undermine vray rt hehe Also, I dont wanna be talking about other engines in general, was just replying to Bertrand.
Its just my personal opinion though, i feel that Octane is behaving as i want in real time, even in complex scenes. Love to hear thoughts from other people as well on this

[vlado]

Dont get me wrong Vlado, i dont intend to undermine vray rt hehe Also, I dont wanna be talking about other engines in general, was just replying to Bertrand.

Yeah, I know, I just couldn't help myself We are asking precisely because we want your feedback.

Best regards,
Vlado