Motion blur streakes

[LeSill]

Hello there,

I'm using OctaneRender-for-C4D-2021.1.6-R4-win and Cinema 19. On the occasions, I have a problem with motion blur. When the instance is marked as "Render instance," motion blur streakes appears all over the instance. It works fine if "Render instance" is not checked in the intance. Unfortunately, it is not ideal when I need to render a large number of instances. Do you have any ideas where the problem could be?

Thank you very much.

[aoktar]

Please read rules of this section and give a better data as written. Thanks for help!

[bepeg4d]

Hi LeSill,
have a look at Raphael quick tip about this:
https://youtu.be/WgQWW5jROvA

ciao,
Beppe

[LeSill]

Hi LeSill,
have a look at Raphael quick tip about this:
https://youtu.be/WgQWW5jROvA

ciao,
Beppe

Hello Beppe,

Thank you very much for the advice. It was an excellent suggestion. I chose the option "hide the original object and animate a few instances." I believe it worked in the previous 4.05 version. So I'll have to go the other way. It's unfortunate that it doesn't work that way. It would make the entire process a lot easier.

[boxfx]

In my experience, render instances should be avoided completely in c4d octane. They are an endless source of problems. Random textures appearing on render instances, textures showing up the wrong sizes, motion blur failing spectacularly, objects showing up as the wrong size, unless you absolutely must for memory reasons, just don't do it.

[aoktar]

In my experience, render instances should be avoided completely in c4d octane. They are an endless source of problems. Random textures appearing on render instances, textures showing up the wrong sizes, motion blur failing spectacularly, objects showing up as the wrong size, unless you absolutely must for memory reasons, just don't do it.

Could you share your experiences with example scenes? Only known issue is with motion blur if you don't change the source object to a proper setup.

Also there is an optimisation option which can cause this.

[boxfx]

Nothing immediately on hand im afraid, I submit problem scenes when possible, but production pressures dont always allow for it; additionally the problems are so intermittent that I already know its of little use unless the problem can be made repeatable.

But examples in the past when using render instances:
- Every render instance model in the scene suddenly replaced with one single model. eg. Every resistor, capacitor, stick of ram, cable etc in a computer case randomly replaced with a rear pcie bracket during an animation.

- Materials applied at the wrong size, artwork rendered at 10x the correct size on render instances, this one is repeatable, i'll see if I can send over a scene

- Motion blur problems mentioned, but silverwings video is interesting, well see if this helps us. We do generally have a hidden null for instanced models but loading in cad absolutely does not do this by default so its a faff to reset things up this way

[aoktar]

@boxfx,
Yes please send when you have issues. I cannot fix the issues without user reports.

[dasmodular]

We struggle with that since we use Octane Render in 2019. We do animations for the mechanical engeneering industry using big amounts of CAD with thousands of instances. Sometimes it takes days to find the one nested renderinstance in a renderinsance that causes the hole rendered image to get blurry when using motion blur on a moving camera.

The issue occurs only when rendering in the picture manager and with more than one GPU. Maybe the mainboard using a PLX chip is part of the problem...

We usually render on 4 workstations each with 4 GPUs.

I will try to make a simplified scene file with that the issue is reproducible at least on our setup.

Kind regards,
Denis

[dasmodular]

OK here it is:

Please open "MB with Renderinstances.c4d".
Hit render in the Live Viewer.
The image should look like "Regular Instances.jpg"
Now render in the picture manager.
The image it renders on all our workstations is "Render Instances.jpg"
It is just the sky color with a blurry shade in the middle.
When you set the three cloners from render instances to regular instances it will render like expected in the picture manager.
I really hope someone can reproduce this.

The cause of that is using render instances and motion blur activated in the octane camera tag.

As I mentioned it only occurs when rendering in the picture manager, in the live viewer it renders as it should.
It doesn't occur when rendering only with one GPU, but starts with two GPUs.

The last four years we could solve this by finding nested render instances.
When you import CAD with render instances it is most likely that you will have render instance in a group that is linked to another render instance.
All previous instances have to be set to regular instances, only the last one in the hirarchy is allowed to be a render instance.
"Disable camera M.blur" in the octane camera tag can prevent this from happening, but doesn't make sense when only the camera is moving and the scene is static.

But now with Cinema 4D 2023.1.2 it seems we can't use render instances at all, when rendering with motion blur.

Cinema 4D 2013.1.2
Octane 2021.1.6
Windows 10
2x RTX 2080Ti + 2x RTX 3090
Xeon W-2125
Asus WS C422 SAGE/10G <- PLX chip (We use MSI Utility 2 to prevent DPC_WATCHDOG_VIOLATION error)
128 GB RAM

Kind regards,
Denis