Question about scene preparation.

jiv21

User Posts: 39
Nov 7, 2025 21:05

Hi Kirgman.

Thanks for the new version. I have a question for you.

I've noticed that whenever there's a frame jump, there's a scene preparation time. And although this time has been greatly reduced, I still notice it.

Does the scene always reload in the engine, regardless of whether there are any animated objects, materials, or lights in the scene?

For example, if only the camera were moving... couldn't the already loaded scene be reused without going through the "Preparing" process?

This would greatly reduce render time for animations without object movement.

If this is already the case, I apologize for the inconvenience and for taking up your time.

Best.

Kirgman

Administrator Posts: 982
Nov 12, 2025 11:07

Quote
jiv21 wrote: I've noticed that whenever there's a frame jump, there's a scene preparation time. And although this time has been greatly reduced, I still notice it.

Hi Jiv, it's possible to optimize this step if the user notifies the render that it shouldn't update the scene but only a camera.
The scene is refreshed completely with full clear and then full reload for each frame.
However, at first Cinema prepares it's document by itself and we can't influence. Then we collect it to the renderer. However the last step is very fast, but it takes something and it's possible to optimize.
I will think how to perform this in the best way.
Whay are you typical frame times for scene preparation and render?

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jiv21

User Posts: 39
Nov 12, 2025 12:17

Thanks for your reply, Kirgman.

I figured it could be done at the user's request. Centileo is incredibly fast, and I don't think I should demand any more speed, but in my obsession with reducing render times...

In my specific case, I can render up to 50,000 images at 4000x2000. So, even if that step were reduced by 1 second, I'd be saving 50,000 seconds. Almost 14 hours of rendering.

Regards.

Kirgman

Administrator Posts: 982
Nov 12, 2025 13:30

Yes, it's important on the large scale, but my interest is how many % of render time is spent for scene preparation and how much % for render of the prepared scene. That can be interesting.
Optimizations will be done in the future of course, it's a never ending story

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jiv21

User Posts: 39
Nov 12, 2025 23:22

Hi again, Kirgman.

Here's a sample video so you can draw your own conclusions. What I see is that it doesn't start the next frame until it saves the current one.

I've noticed in other engines that the save time is independent of the start of the next frame.

https://www.mediafire.com/file/uo1orxgnj43x46h/Kirgman.mp4/file

Best.

Kirgman

Administrator Posts: 982
Nov 13, 2025 05:59

Hi Jiv, the breakdown looks interesting, so we have around 20 sec for single frame production: 1-2 sec for scene preparation, 12 second for rendering itself and 6-7 seconds for frame storage.
It's a lot to store a frame! Cinema 4D is saving these frames by itself. Maybe experiment with different output image file formats?

I remember rendering 10K image stills of huge 3D model, 4-8min per frame, see https://centileo.com/gallery/ (scroll until Engineering Stills). That time 1 min was needed to save a 10K png image. It's pretty much comparable to render time.

Quote
jiv21 wrote: I've noticed in other engines that the save time is independent of the start of the next frame.

Do they start next frame while saving the image from the previous one? In Cinema 4D? It looks possible, but need to understand whether Cinema 4D programming SDK actually allows to do this. I will be able to do such a trick in a custom standalone app.

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jiv21

User Posts: 39
Nov 13, 2025 08:33

Thanks for your reply.

I assumed that saving the image was something separate fr om Centileo, but my drives are M.2 SSDs with speeds of 7,500 MB/s, and it doesn't matter which drive I save the scene to.

Understanding that it's always better to save to a drive separate from the operating system or the one wh ere the software (in this case, Cinema 4D) is installed, the time is the same. These are 4000x2000 PNG 16-bit images (between 25 and 35 MB), which shouldn't be a problem for such fast drives. That's why I asked.

However, in Chaos Vantage, I get one image every 2.2 to 3.5 seconds, and it's not affected by saving the image. It's as if it doesn't take into account that it needs to save to start the next frame. I suppose it stays in some buffer and is saved when possible, taking as long as it needs.

Thank you for your time.

Kirgman

Administrator Posts: 982
Nov 13, 2025 10:50

I mean that using the SSD of good speed can't help here too much. The Cinema 4D takes the raw render image and converts it to PNG, especially 16 bit, it's quite a time consuming encoding. Maxon probably didn't optimize it, but use some fixed old pipeline structure.
Probably not a png, but a different image format may be faster.

In a separate standalone program, such as Vantage, it's possible to make storage in a background process in parallel to rendering the next frame.
I think we can do this too, with a future standalone app.

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jiv21 User Posts: 39 Nov 13, 2025 16:26 #9 Thank you so much for the explanation and the attention you give to my questions. Clearly, there are processes that I don't fully understand. And regarding the internal image compression workflow in Cinema 4D, even with a top-of-the-line processor... if it doesn't use parallelization or is outdated code... Thanks again for your patience.

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