V-ray 3.5501 RT/GPU render issue

[garth100]

Guys, I am asking for support from the pros. Currently, I am testing V-ray RT-GPU. Not sure what I am doing wrong. When rendering with GTX 980 ti, the scenes takes a very long time to load and render very slow as well and even pause in the process and at times don't even render. The max file size is only 29.964MB

Troubleshooting
I have resized the textures with V-ray texture resize option.
Resize HDRI to about 3K
Mesh such as sofa and bed converted to V-ray proxy
Swap around the video cards to different PCI ports on the Motherboard

Question -
Should I just convert the textures in photoshop (what texture size recommend for 2K-4K render)
Upgrade the video card
Or just use CPU only
Would overclocking the GPU helps

I have done single car rendering. The speed and load time was ok. Just want to put that info out there as well.


Render engine; Vray nightly 3.5501
3D program: 3DS max 2017

Computer specs
Motherboard: Z10PE-D16 WS
CPU: 2 Xeon E5-2683 V3 - (water cool)
Video cards: Nvidia GTX 980 ti ((6gb ram) )-for RT GPU rendering
Video cards: Nvidia Quadro 6000 (6gb ram) -for viewport performance
2 Ram: 16gbs of Samsung ram = 32gbs
Drive: SAMSUNG 850 EVO 2.5" 250GB SATA
Operating system: Windows 10 Pro

Thank you all in advance!

[Alex_M]

Hmm... this sounds strange. Can you post a screenshot of a scene that is affected by this problem so we can see how complex it is? Did you render with the default render settings? Did you choose CUDA as the engine? What happens if you apply a clay material to everything? Did you try different drivers? I'm using Vray 3.5 Beta 1 with a single GTX 980 (non Ti) quite often and I've not noticed any problems even with more complex scenes as long as they fit in the memory. I've render cars and some moderately complex interiors and exteriors without issues. Does this slowness still appear in a very simple scene like a teapot and a single vray light for example?

[svetlozar.draganov]

Not sure what I am doing wrong. When rendering with GTX 980 ti, the scenes takes a very long time to load and render very slow as well and even pause in the process and at times don't even render. The max file size is only 29.964MB

Would it be possible to send us that scene to support@chaosgroup.com
Please include a link to this tread and let us know if there are other scenes which have the same issue or this is the only one.
Is there any difference in the exporting times if you disable the texture resizing or if you disable the textures completely?

Should I just convert the textures in photoshop (what texture size recommend for 2K-4K render)

You can do that of course, this should save up some exporting times but we can't predict how faster it would be so it might be a good idea to test it.

Upgrade the video card

Faster cards will certainly help reducing render times but it would be better to first investigate the scene since there might be some bugs in the software.
Since you already have two cards, GTX and Quadro - did you try to render the scene with both of them?

Or just use CPU only

It is a good idea to test how this scene renders on the CPU. Check the export and render times and compare them with the ones from the GPU.

Would overclocking the GPU helps

It depends how stable is the GPU after the overclocking. I don't have a stable overclocking background and don't know how much faster the card could be when overclocking it but I suppose that every % above would help reducing render times.

[garth100]

Thank you Guys,
I will do some more testing and upload the file for further testing later today as well.
Thank you all!

[biochemical_animations]

Keep testing.

I have completely moved to GPU rendering because of the magnitude of render speed I get over CPU. Sorry, but I don't have an idea on your issue, but what I do, is isolate things, test render in simple scenes, take objects out and put them into a clean file and test. GPU rendering is a delicate dancing around eggshells, more so than using vray adv. It requires really knowing what all is going on, becoming a master at it (not that I am). If you don't understand something, take some time to figure out what it is...you will be glad you did.

Use active shade for real-time stuff and building, production render with low noise settings (like .1 or .05), region render for areas to fix. Try rebuilding some stuff with your textures and test render times and load times and try and figure where the problem is.

The GPU engine I believe totally approaches things from a different angle than CPU...the textures are baked in in some cases, and handled differently, to the best of my knowledge.

You are on the right track, once you get the knowledge down for your area, you can get things done very quickly. I hope this helps.

One other thing, I found I have to approach the beginning building of a scene from the GPU rendering perspective, because there are things I cannot use in GPU or have to do differently than CPU rendering...I have found I cannot take a scene that I rendered and built using vray ADV and expect it to work with RT GPU CUDA mode. That is why building a scene from the beginning while rendering along the way, saving, reloading, etc., all helps you become a master (or your own master at least) at GPU rendering.

I haven't used vray proxies, my hdri's are 10kx5k and load and render fine, I have a max files size of 150MB and it loads fine, OCing my GPUs (2x980ti's classified with custom flashed bios') helped me gain ~20% speed (I actually got about 25% but the temps and fans were running high so I backed off a bit).

[garth100]

Totally understand. I will try to do and upload a video on the progress.

I really think GPU is the way to go due to the speed and quality. I did over clock the GPU last night from 1200mhz to 1500mhz. I did try a simple car scene rendering on the GPU. The render time was under a minute(crazy fast). More update to come though.

Thank you!!

[garth100]

My apologies for the delay. I have done some modification to the scene. The scene did render but I find it to be slow. (Just a test)The same scene loaded and render fast with Fstorm. Maybe I am missing a step at this point. I did discovered that when rendering simple scene the GPU render very fast. I guest GPU render is not for everybody. Please see the attached images and video.

Resolved issues:
Unsupported materials- cg-source multi texture map and color correction

Addition corrections:
Resized HDRI to 2K
Removed unnecessary maps.
Resized materials - total map/textures size are 81.3MB

[garth100]

[biochemical_animations]

Have you tried the TriPlanarTexture? I've had to put an unsupported Bercon map procedural inside it to get it to (sort of) work, but it worked well enough. However, if I went to crazy with the layers, it stopped working.

[savage309]

Have you tried the TriPlanarTexture? I've had to put an unsupported Bercon map procedural inside it to get it to (sort of) work, but it worked well enough. However, if I went to crazy with the layers, it stopped working.

The triplanar texture on the GPU does not support procedural textures.
It works with the Bercon, because we try to bake the unsupported procedurals to bitmaps.
Best,
Blago.

[garth100]

Currently I am running max 2017 and I don't think bercon compatible with max 2017. I will remove the triplaner and try again.

Question- if Vray RT detected unsupported mat/textures, will it attempt to render and also in return use up a lot of memory trying to calculate the scene?

[savage309]

Question- if Vray RT detected unsupported mat/textures, will it attempt to render and also in return use up a lot of memory trying to calculate the scene?

If V-Ray GPU detects unsupported texture it prints warning about that in the log and tries to bake it to bitmap.

Best,
Blago.

[garth100]

Got it. Thanks!