V-Ray render times

[david.anastacio]

Hi everyone,

I'm in the process of testing V-Ray for Houdini, and comparing render times between Mantra and V-Ray.
Initial tests on point to a dramatic time diferential between the 2 renders, 7-8 times faster renders in V-Ray with the same scenes/lights/shaders and visual sampling quality.
Has anyone else arrived at this same speed increase comparing to mantra?

Best,
David

[glacierise]

Yeah it's quite fast

[Muhammed_Hamed]

Yes, part of why we love Vray, it is been our first choice for CPU rendering for some time. And on top, the Houdini Vray team has been doing a great job! This is the best Vray plugin in my view.
About rendering speed, specially Vray CPU in bucket mode.. it has had so many optimizations throughout the years, you would see that on memory usage as well
The fact that there is one single slider for all sampling settings, works nicely 99% of cases
Vray uses 100 GI bounces by default, and shreds through interior scenes without the need of light portals. Nothing come close in speed

And there is definitely room for improvement, Bokeh noise is not easy to solve in Vray, glass is 10 times slower to render when you use dispersion and HairNext material with fur can be slow.. Other than that, everything has been so fast for us

Best,
Muhammed

[hsz]

I want the GPU to become as powerful as Redshift and support as much as it does in the CPU.

[Moriah]

Personally my biggest drawback is all the Houdini's network rendering workflow. It's very non-intuitive and inefficient. Either with Vray or Arnold or Renderman or Mantra, the process of having to convert all your scene assets to a renderer's format (using either engine or GUI licenses), and only then you can render the scene in non-gui mantra nodes is awful. And i won't even talk about Deadline + Houdini + Vray...

Why can't it be as simple as any other DCC app? Press a goddamn button "Submit to network rendering" and done. Wait for your render to finish.

I really hope SideFX will change this soon enough... A lot people i know don't switch to Houdini partially because of this setup.

Rant aside, Vray for Houdini seems pretty stable and mostly complete compared to a year ago when I last tested. Biggest difference i still notice vs 3dsmax, is the lack of IPR responsiveness, still slow and only updates when the mouse is finished pressing.
On the other hand i love all the new Math nodes, new noise types and the way we setup render channels in Houdini, again compared to 3dsmax.

Material previews are lacking too, but then again this is SideFX's fault for not implementing it on the mat network. Same with texturing viewport previewing via OGL, fortunately vray has a few, but this thing should be available and easy to do in Houdini.

[Gosho.Genchev]

is the lack of IPR responsiveness, still slow and only updates when the mouse is finished pressing.

Hey, this is a Houdini thing - there's a setting under the Viewport called "Export View Continuously" that will force IPR to behave similar to Maya/3ds Max.

Thank you all for the great feedback, we're all following the thread with great interest.

[bdancer]

> still slow and only updates when the mouse is finished pressing.

Events are coming from Houdini; for "On Mouse Up" mode it'll update only on mouse release, for "Auto Update" updates will arrive much more frequently.
For there camera movement there is a new parameter in 18.x "Export View Continuously" in the viewport dropdown menu.

[Moriah]

I did try it and indeed it's very close to 3dsmax's responsiveness now! Also forcing undersampling to 5 made it even faster.

Request - when we're running IPR can you force enable this setting? I didn't even know this setting existed before, and i think most people using vray for houdini don't know unless they visit this forum and search for this topic. Maybe make a button in vray's IPR tab to enable/disable this but having it enabled by default?

Also something i'm missing is the % render settings button on the VFB

Another one is the dynamic IPR window rescaling, right now it's tied to a camera res, is it possible to have it like in 3dsmax?

[david.anastacio]

Thanks for all the answers, busy week for me so could't get more feedback in sooner.

Overall VRay implementation is really nice, as a long term user of VRay in 3dsMax (12 years and counting) this was a great experience. The render speed, the ease of use and the performance was rock solid, no crashes whatsoever.
Some bugs, but that's normal and that showed us how the interactions with the support team went, and they we very responsive which is very reassuring for when you hit a snag during production.

Besides the render speed which was a great plus for VRay compared to Mantra, VRay also gives us the advantage of easily transition our artists and even freelancers from 3dsMax/VRay to Houdini/VRay.

Regarding the render times comparison, Mantra really loses on not having adaptive sampling on primary rays. When you have a dark scene with bright highlights and you need to render an effect (DOF, Motion blur), you really need to crank up the pixel samples to get good quality on that effect, but that also makes it completely oversample unneeded areas.

In this example VRay cleared the image in 1/3 of the time, and if I match the same max subdivisions amount (12), it cleared it in 1/5 of the time.
VRay shredded through the dark areas as Mantra slogged through them, you can see what it was doing if you gamma up the image, those are some pretty nice shadows on the Mantra render.....
Also time to first pixel is quite faster in VRay either on the Production render or the IPR which really helps with the artists daily quality of life.



This brings me to what I thing is actually the most useful feature of VRay...... the unified sampling. The render quality is contrast based and it can be controlled by one simple value, this is a very powerful feature, not that this is new to me, quite the opposite, just surprised other have not adopted it yet. This gives the artists more time to work on the shots and improve them rather then fiddling around with light samples, light radius, component quality and trying to balance all this out takes time from the already limited we all have to finish our projects.

Unified sampling allowed us last yer to render some gigantic scenes for Lost in Space season 2 rendered in 4K with interior scenes, hundreds of lights and 50 deforming robots made of metal..... We were able to deploy referenced setups through all the shots that required no input from lighting artists on the render settings.



Also thank's for the IPR tip @bdancer and @Gosho.Genchev.


Regarding the network rendering that @Moriah mentioned, that's more of a Houdini feature than a VRay problem I think, due to Houdini requiring a license if you want to render without using IFD/VRayScenes.


Best,
David.

[Fridayvfx]

Your images look like a good ground for a copper army to walk on.

-Robert

[Muhammed_Hamed]

Thanks for the input and thoughts David