Slow render with upgraded Vray

[mk0508]

Hello all, I am new here and relatively new to SU and VRay. I?ve recently upgraded to Vray version 3 (3.40.04) from a very old 1.49. At the same time upgraded from Sketchup 8 to sketchup 2017. My problem is I used to be able to have a render done n 25-30 minutes. Now exactly the same file takes me 2 hours minimum. What could possibly be the reason? Do I need to provide any additional information?
Additionally, when I try to s elect ?GPU Acceleration? option hoping it will speed things up it crashes SU and gives me a brief error message about my NVDIA stopping to response. What am I doing wrong here if anything? Should I not be using GPU acceleration?
Thanks in advance.

[delineator]

Could you give us an idea as to the specifics of your system?

Also, I'm assuming the issue is some old material files being translated from v1.49 to the new vray version maybe are not super efficient. Use BRDF mats whenever possible.

Try resetting the settings on the scene and rendering and seeing if the defaults for v3 fair any better.

Regarding gpu usage, it depends on your scene, your hardware, your settings, etc. Keep in mind that until we get hybrid rendering for SU, then you are limited to your graphics memory

[mk0508]

Thanks for responding. Attaching my system info, + gpu is NVIDIA Quadro K420.
I will check out if old material may be the issue, but wanted to make sure the new Vray (3) version is not overall slower ( i was hoping it would be faster..) as it suppose to be more complex producing better quality.

[delineator]

Oh, ok. Well, yeah, definitely don't use GPU rendering on that card. Depending on which version you have, it may have 1gb or 2gb (neither of which is enough for almost anything you are probably rendering). I'm guessing that you are maxing out your ram whilst rendering, which means you are probably hitting your page file a bunch, which is definitely slowing things down.

I'm not going to touch the fast vs slow discussion, but I would look at it as different. The core engine is probably very similar, but there are differences now, notably in how light is calculated, etc etc. If you are running into issues, I would recommend a ram bump - take a look at your task manager and see what your ram and drives are doing next time you render. I bet that would offer a clue

[georgi.georgiev]

Hi,
Does the issue occur for specific project or any (even newly created ones)? If it is for specific project, could you share it with us so we can investigate in detail? Please send us an archived copy (Extensions > V-Ray > Export > Pack Project) to support@chaosgroup.com

Additionally, when you open the project, could you reset the settings to default (Asset Editor > Settings > Revert to Default Render Settings) or use the preset quality settings (Asset Editor > Settings > Renderer > Quality) and see if the issue persists?

Regarding the GPU Acceleration, which drivers are installed for the NVIDIA Quadro K420? Does SketchUp crash shortly after initiating the render or at a certain point of the render progress?

[sigrid]

Hello, I'm trying to use the new vray 3.4 since the 2.0 has expired, sadly... Renders take SOOOOOOOOO long!! Even with a simple model with 2 blocks and 1 spotlight in a room and no "old" materials, they take ages to complete...
I'm used to rendering at 2400x2400 pixels in 2.0, complex interior renderings took only 30 minutes on my system! And when I used distributed rendering they were done in 6(!) minutes each!
WHAT is going on? What is causing this?
I upgraded to the 3.4.004... So I have the latest version installed. Working on SKP 2017.
Man, I miss 2.0 What a mess! All materials and libraries down the drain, it's taken me 6 hours to draw a bathroom I normally do in only 2... I can't make clients pay for 300% of the time!
And I sure don't have the time to wait 2 hours on 1 image... HELP!? :'(

[georgi.georgiev]

Hi sigrid,

I'm sad to hear that you've had such experience with V-Ray.

Does the issue occur in brand new scenes as well?

Kindly note that using ?.vropt? or ?.visopt? files created in previous V-Ray versions is not recommended as some outdated parameters may cause unexpected results.

Could you please try resetting the settings to default and use one of the preset quality settings (Asset Editor > Settings > Renderer > Quality)? Keep in mind that, being part of the render settings, Camera parameters and the Environment texture will be reset as well.

Let me know if that helps. For further assistance send us an email at support@chaosgroup.com so we can properly follow up and get to the bottom of the issue.

[sigrid]

Hi Georgi,

The issue does occur in brand new models as well... Created in sketchup 2017, only with materials coming from Vray 3.4 and no old components imported.
Sketchup crashed 3 times in about 2 hours as wel. I wasn't doing anything special what could have caused the crash... (just orbiting around my model)
I haven't imported any old visopt settings... So I would assume that that's not the cause either.

I have now created 3 renders 1800by2250 pixels and they took 1,5 hours to render, each... In 2.0 that would have taken 10 tot 15 minutes (without distributed rendering).
As a test, I timed a render of a newly created skp file, with just a room, 1 opening for sunlight (no glass or window) 1 spotlight and 2 white blocks. The only "complex" material is the floor, which is a standard material from the Vray Library. I rendered at 1200x1200 pixels at quality "high". It took 11 minutes and 47 seconds... Almost the same as the kitchen image I attached, that's bigger (2160x2160) and way more complex. That rendered in 12 minutes.

Also, on the side, I can't find the parameter to reduce the burn value anymore? Where would that be found?

Is there any way we can extend the use of 2.0 (I even want to pay for it) as right now I'm losing valuable time (and therefore losing income)... I have a massive library of sketchup models with vray2.0 materials on them, ready to render, it's almost impossible to redo them all...

Don't get me wrong, I'm a huge fan of Vray, I have been for many years now... (I even used to teach Vray 2.0 from time to time in architecture offices).

I hope this time-issue can be resolved, that would be a great first step. The library will take a lot of time but that's a long-term project then...

Sincere greetings,
Sigrid

[peerman]

Hi Sigrid,

I made a similar room (about 5x5m and 3m height) to check. I only used the sun, so no spotlights. The room rendered in about 2m49s on my 5 year old iMac. I used the IM-LC combo. The standard is BF-LC which took me 12min to render. So have you looked at the GI settings? BTW you can now find the burn settings in the post production menu (under the renderwindow it's the most left icon). If you like I can look at your testscene?

Best,

Peter

[sigrid]

Hi Peter,

YOU ARE AN ANGEL!

I tried it and now it rendered in 1min 35sec. Still longer than 2.0 would, but a massive improvement! I'll try rendering the bathroom again that took 1,5 hours yesterday and see if this helps in a "big scene" as well.. Fingers crossed.

Many thanks and have a nice weekend!

Sigrid

[sigrid]

I tried the scene I did yesterday, it took 27 minutes. That's 1/3 of the previous time, but still way more than the old version... Any more tips to speed things up?

[peerman]

Hi Sigrid, Glad I could help at least a little bit. Are there a lot of lights in your scene? Another way is to use the progressive render in combination with the denoiser. This way you can let it render for say 10 minutes and let the denoiser do it's work. I use this method if I don't have a lot of time. You loose a bit of detail though. Maybe you can share some of your scene?

Best,
Peter