Constraint Tag Final Rendering Issue

[Rickmc]

Hello forum,
I have a problem here and can't find a solution.
I urgently need help as I have to deliver today.

I attached a card to the inside of a box using a constraint tag.
When I activate interactive render everything is displayed correctly, but when I finally render the card is no longer on the right position.

The box lid is animated.
In interactive render mode, V-Ray does everything right except in the final render.

I'm still working with C4D R21

Does anyone have an idea?

[aleksandar.kasabov]

Hello Rickmc,

Could you please share some more information about your setup? For example, is the card a child of the box? Can you send us a screenshot of your Objects structure or if possible, the scene or a simplified scene where the issue is reproducible? You shouldn't experience problems with the Constraint tag, but something with your setup could mess things up. Thank you.

[Rickmc]

Hi Aleksandar,

here is a stripped down version of the project.

It's about “Card 1”.
It's a child object of the box but the problem also occurs when I take card 1 out of the hierarchy.

Thank you for your support

Box.c4d.zip

[aleksandar.kasabov]

Hello Rickmc,

I can indeed see the issue that you are experiencing with the constraint tag. I have already reported it to our developers and they will see if it can be fixed. However, due to the short deadline that you have, I am afraid that probably we won't be able to fix the issue in time. As a workaround, I can suggest you to split the "Box" object into two pieces (1 for each cover) and make the card a child of the opening cover. That way, it will rotate with the cover and will be rendered correctly.

I hope this is of help.

[deyan.hadzhiev]

Hi Rickmc, in the final shot you provided - is it part of the whole animation rendering or you only rendered the current frame as a final render?

I'm asking this, because Cinema 4D sometimes requires the full animation to be rendered in order for some simulations to be evaluated as expected. Since the constraint tag is actually part of the simulation system (it has option for evaluation order and needs to be evaluated per-frame) it seems it requires the whole animation to be renderer to properly evaluate the position of the card. Here is an example screenshot of your scene (with reduced quality and the card material changed to be more visible) rendered as an animation:


This is further revealed as general Cinema 4D problem if you try using the Standard renderer (with an override material) and render only a single frame:


Edit:
Sorry for the edit, but I thought of a kind of a workaround you may try to actually avoid rendering the full animation to simulate the scene properly. You simply need to render the full animation, but you may specify a frame step of the actual frame you need rendered, like so:


So you will end up rendering some additional frames, but the simulation should match what you observe in the viewport.

[Rickmc]

Hi Deyan,

I actually haven't tried it yet.
Now that you mention it, I remember that C4D has to calculate the entire animation from time to time.

I'll test this right away.

Thanks

[Rickmc]

Hello Deyan,

for some reason it doesn't work for me.
Frame range is set to “All“
Frame step up to “1“

I have rendered the first 50 images.
Except for picture 50, the Card is floating.
See pictures

I have now solved it frame by frame using keyframing.

But don't worry now.
I have to expect that sooner or later problems will arise with my old C4D version.

Thank you for your support.

You can be relied upon.

Best regards