V-Ray 3.7/(5) - Saving Time of Frame and Cleaning up Scene for another Frame takes AGES

[PdZ]

Dear Chaosgroup,

while rendering geometry-heavy scenes with a lot of proxies, geometry, whatever:
When Rendering a frame with Bruteforce/Bruteforce (i think its the same with anything else) V-Ray does not take long to calculate the rendering BUT the process of cleaning up the ram or what ever V-Ray does to
start the next rendering is horrible slow. V-Ray is just using one core and for instance with my current scene: It takes 3 Minutes to render a HD Frame but 10 Minutes to just SIMPLY WAIT for V-Ray to save the frame and start the next render.
I dont understand that and it costs so much time. usually it would take only 30 Minutes with 3 Minutes per Frame to render 10 Frames. But because V-Ray is cleaning the scene sooooooooo long it takes additional 100 Minutes. So Rendering an animation
is absolutey atrocious.

Its the same when stopping a rendering. V-Ray seams to clean up the ram so horrible long. Does any Chaos Group Developer explain what is happening here?

btw. no joke: Its often faster to save the frame in the pictureviewer manualy by hand and crash C4D, open the scene and render the next frame. Its faster than V-Ray is able to clean up the scene or saving the frame.
But thats obviously not an option...

Thx in advance!
PdZ

[RwVision]

Definitely another problem to solve. Hoped it would be better in Vray 5, but it turns out it's slower and unfinished vs 3.7.

[PdZ]

Are you serious?
i thought when Chaosgroup is rewriting V-Ray there would be hope.

That cant be true. How is someone able to render an animation?

Iam not joking. I think this one if the most serious matters. I checked a lot of things and in my oppinion it relies heavily on how many objects and materials are in the scene.

I will try out V-Ray 5 in the next couple of weeks. If thats true RwVision then thats absolutely unfortunate and there must be any solution. In future we want to render more and more animations but that weird bottleneck is really crazy.

I can just assume that Vrays cleaning up the Ram-"process" takes so long because C4D and V-Ray are not working good as a team? Is it the same in 3DSMax?

I like all the great developement results now and that V-Ray 5 is out now. All the new features are absolutely GREAT.

BUT! We need first: stability and speed.

It would be really great if some developer could give some support here.
I volunteer to be a Beta-Tester or I try to figure it out on my own like a lot of things I already figured out which i posted here in the Forum. I dont want to switch to another engine. It would be a big shame. V-Ray is great apart of stability and speed (speed in regards of before mentioned cleaning process of Ram after a rendered frame).

Apart from that it would be great to improve preparing time for frames. Because they always be prepared by just one CPU-Core, which is a major bottleneck.

Kind regards,
PdZ

[RwVision]

Are you serious?
i thought when Chaosgroup is rewriting V-Ray there would be hope.

That cant be true. How is someone able to render an animation?

Iam not joking. I think this one if the most serious matters. I checked a lot of things and in my oppinion it relies heavily on how many objects and materials are in the scene.


Kind regards,
PdZ

Hi,

I thought you were already testing and commenting V5 - let us know how it goes on V5. I've only tested one bigger file and prep/finish times were not perfect. Sometimes prep was longer than 3.7.

Please keep testing

[PdZ]

Btw I can only assume it is very hard to code an engine and iam really excited that V-Ray is finally that modern in Cinema 4D. I dont want to sound to be not thankful of that.

I really am! Especially GPU Rendering and Multipass/Renderelement Enhancements are very welcome. But for me its kinda weird why V-Ray takes sooooo long to solve just to clean up ram and Rendering next frame. You can see that behaviour very clearly. It seems dependent on how complex is V-Rays Rendering Tree I think. But in my oppinion there must be a ways to tell V-Ray like "After render is finished -> delete V-Ray Render Tree -> start next frame".

Maybe the memory allocation is random and takes time like a fragmented harddisc or so. Iam not a developer.

As a sidenote: After I spoke to Maxon about the problem that Cinema 4D takes ages to open or save Cinema Scenes (.c4d) it took me just 2 days to figure out what is wrong.
After speaking like 4 Times to Maxon Support it turned out that Cinema 4D (also the newest C4D) is saving and opening scenes in a very outdated Byte-format which needs to be converted to when saving c4d and converted back when opening c4d while using just one cpu-core. It sounds like somewhat samish behaviour at V-Ray handling scenes internally in RAM.

Btw for interested ones: If you save a scene in Blender it does not use this outdated behaviour and uses full speed of any SSD or m.2 SSD.

OK I digressed a lot from the main issue here but I think these RAM and Saving/Opening issues are really a problem.

Would be a shame if this is not taking seriously or getting ignored here
Greets,
PdZ

[PdZ]

Hi,

I thought you were already testing and commenting V5 - let us know how it goes on V5. I've only tested one bigger file and prep/finish times were not perfect. Sometimes prep was longer than 3.7.

Please keep testing

I was currently very busy working on a project, so I had no time at all to test V-Ray 5 but I ordered a new PC-System today to try out GPU Rendering and also everything else at home. I will definately try out new V-Ray and check if its worth. Just to be clear: I love V-Ray but I just want to be honest.

Greets PdZ

[shaio]

Hi,

I thought you were already testing and commenting V5 - let us know how it goes on V5. I've only tested one bigger file and prep/finish times were not perfect. Sometimes prep was longer than 3.7.

Please keep testing

Hi,
I can imagine that there still could be areas that we didn't cover and still need to be optimized. We're testing with a variety of scenes here but there could always be something that needs optimizing because of everyone's different workflows that could lead to slowdowns. We're doing our best to optimize V-Ray so whenever you experience slowdowns on different scenes please share them with us, so we can profile them and find what is causing the slowdowns because recreating the same scenarios on our end doesn't always work.

Definitely another problem to solve. Hoped it would be better in Vray 5, but it turns out it's slower and unfinished vs 3.7.

It is unfinished because it is a rewrite and a lot of the features are still written as we speak. Development something like this takes time and trying to make it right takes even more time. If we were to wait until V-Ray 5 reaches the amount of features like in V-Ray 3 then unfortunately there wasn't going to be V-Ray 5 for Cinema 4D any time soon and the other V-Ray integrations would have been quite a lot ahead of V-Ray for Cinema 4D.

[haniel1107]

I was hoping to use Vray5 already for production, but it crashes to many times (heavy scenes with animation) and to be honest still too many bugs and missing features.
But to play around with Vray5 is great and will be greater soon, I am sure.

But for me, I wish I would have been purchased later... or one or two months longer beta phase...

[PdZ]

Hi,
I can imagine that there still could be areas that we didn't cover and still need to be optimized. We're testing with a variety of scenes here but there could always be something that needs optimizing because of everyone's different workflows that could lead to slowdowns. We're doing our best to optimize V-Ray so whenever you experience slowdowns on different scenes please share them with us, so we can profile them and find what is causing the slowdowns because recreating the same scenarios on our end doesn't always work.


It is unfinished because it is a rewrite and a lot of the features are still written as we speak. Development something like this takes time and trying to make it right takes even more time. If we were to wait until V-Ray 5 reaches the amount of features like in V-Ray 3 then unfortunately there wasn't going to be V-Ray 5 for Cinema 4D any time soon and the other V-Ray integrations would have been quite a lot ahead of V-Ray for Cinema 4D.

Hey shaio,

As I said, we know its a lot of work and we are looking forward to it.
A lot of People here in the forum mentioning missing features like better denoising or V-Ray Clipper. Yes these tools are absolutely nice to have and we need them BUT when it comes to the absolut necessary things: I think overall speed is a big problem.

Iam currently rendering a scene which contains only 2sided, Standardmaterials, carpaint materials.

It contains animated trees as alembics and animated cars as V-Rmeshes. And is very big in RAM. About 48 Gigabytes full.

As a developer it must be very hard to figure out things so I will try my best to help here in the future. So when my PC is arriving I will test out especially the "problem" with horrendous saving Frame/cleaning RAM-time and what to do about preparing time, what causes it to slow down etc.
I think a lot of people here are unaware about these extreme technical details and therefore maybe ignoring this or do not care or dont work with heavy scenes. But I work with Vray for over 10 years now and especially the problem with saving the frame after rendering is my biggest issue.
Iam currently rendering with a AMD Ryzen Threadripper 3970X 3,7GHz 32x Core So.TRX4 and 64 Gigabyte Ram with help of M.2 NvmE SSDs.

I will check and post my results here later then.

Kind regards,
PdZ

[PdZ]

shaio :

I already mentioned that but I want to point that out. I think V-Ray was developed in mind of having more and more CPUs avaiable and it is rendering extremely fast now but in my opinion there are just two big bottlenecks right now:

- preparing the scene to render, preparing scene for frame, exporting objects (render terminology) just use only one or two cores, which costs so much rendertime. If that is multithreaded, this would speed up the Rendering in an extreme way
- After rendering watching the taskmanager: you can clearly see that V-Ray is cleaning up the RAM. This also is happening with just one core and its horrible slow. The more RAM you have/the bigger the scene is the longer and slower it is to clean up the RAM.



Shaio is there a more detailed documentation around on what V-Ray is doing especially when I read those lines in the console (and in the left bottom corner from Cinema 4D)

• Preparing scene for Rendering
• Preparing scene for frame
• Exporting objects

Iam very interested in knowing what V-Ray is exactly doing here. I can only assume that preparing to render means that V-Ray is collecting all the currently in scene necessary data (which objects are set to render, which tags are assigned, which renderinfo is given, which lights are on, setting up internal hierarchy tree).
What does preparing scene for frame do?
Exporting objects into the RAM as voxelbased VR-Meshes so V-Ray can handle it because V-Ray is internally working with its own voxelbased format instead of polygones? It is necessary to understand V-Ray completely to know/solve the issues or where to optimize. For me its like trial and error or like reverse engineering. It would be a absolute bighelp if you could share more details to the V-Ray core. Not the Code of course but as I mentioned above, what V-Ray is doing. More exact, more detailed.


Thank you in advance!

Kind regards PdZ

[shaio]

Hey PdZ,

preparing the scene to render, preparing scene for frame, exporting objects (render terminology) just use only one or two cores, which costs so much rendertime. If that is multithreaded, this would speed up the Rendering in an extreme way

Rendering sometimes could be slower not because of the export being single threaded but something else. Our other V-Ray integrations are also single threaded and the export isn't that slow.
It would be great if you can share one of your scenes that we can use to profile what could be the cause of the slowdown and optimize it. We do have and test very heavy scenes here and the export times are not that slow. There might be something in your scene(s) that causes this.

- After rendering watching the taskmanager: you can clearly see that V-Ray is cleaning up the RAM. This also is happening with just one core and its horrible slow. The more RAM you have/the bigger the scene is the longer and slower it is to clean up the RAM.

Can you please export the whole scene to a single ".vrscene" and render it with V-Ray Standalone while keeping an eye on the task manager and the amount of RAM that V-Ray uses as well as how fast it clears up? With this test we would be able to see if the issue is caused by V-Ray or something in Cinema 4D or maybe even both.

To render the V-Ray scene (.vrscene) with V-Ray Standalone you need to navigate to your plugins folder under "V-Ray\res\libs\win64" and run "vray.exe -scenefile=yourscene.vrscene" in the command line to render it.

It would be a absolute bighelp if you could share more details to the V-Ray core. Not the Code of course but as I mentioned above, what V-Ray is doing. More exact, more detailed.

When you export the .vrscene file you can start rendering with the command described above and if you add -verboseLevel=4 it will output a very detailed log and show you what is going on at the current moment and might help you see what exactly is causing the slow down.
Here is a full example of how the command for rendering with V-Ray Standalone should look like (some folders are going to be an example folders please keep that in mind):

"C:\Program Files\Maxon Cinema 4D R23\plugins\V-Ray\res\libs\win64\vray.exe" -scenefile="C:\myscene.vrscene" -verboseLevel=4

Here is an example how the log will look like:


Let me know if this helps.