Cineversity

Good afternoon,

I am new to this forum, but have been using C4D for more than 20 years.

However, my current Dynamics problem is proving tougher than expected.

In the attached file, I have modeled an object (Blue) that is attached to the blue circle, which rotates.
Attached to Blue is another object (Red) that is supposed to mimic something that is hanging off of Blue.
Now, as you hit play, Blue starts rotating and Red experiences centrifugal force which forces it to swing out.

It currently swings out ~45 degrees, which simulates probably a plastic material.
How can I change the weight of the A object to simulate a heavier material, such as lead or iron / steel?
I have played around with center of gravity, mass, density, and friction, but none have a visible / realistic effect on the swing angle.
The only thing that helps a little is to increase gravity to 4x-5x, but even then the material still swings too fast and high.

I am trying to use this setup in a carousel model where the gondolas swing out due to centrifugal force.

I hope this makes sense; if not, I’m happy to answer further questions.

Thank you,
Chris

Hi Chris,

Thanks for the images, but normally images don’t tell a lot. If possible, I prefer scene files. (The forum needs them zipped. If there is a problem, I can send an upload link.)
Before you use anything that I wouldn’t touch, for security reasons, please only DropBox, Google Drive, Apple, Adobe, Wetransfer, or Amazon; thanks for understanding.

I have uploaded two options here. One file is with default Dynamics (cached), and the other one is based on Xpresso, which I would use in this case.
Files:
https://www.amazon.com/clouddrive/share/ufNYXGKXNdzgzXtyImFgoXSPzExplPeJCHS9ihbLRUt

All the best

Hi Dr. Sassi,

Completely understood on the images vs. uploads.

If we look at the scene you compiled with Dynamics, it is a perfect representation of my scene!
So, right now, the yellow item swings out quite far, like a plastic object would.
How can I make the yellow object appear to be heavier, steel-like let’s say, so that it doesn’t swing out as far while rotating, and once you stop the rotation, it swings slower as well?

Hi Chris,

Thanks for understanding my concern with the images. Very much appreciated!

The powers seem to be in sync with what I would expect. The rotation is getting pretty fast; no gondola carousel would be that fast. (My personal idea about it). However, you are the art director here; you want to have it differently, so let’s do that.
Use a Main Menu> Simulate> Forces> Gravity.
Place that into the List of the Dynamic tag (Include!)
https://www.amazon.com/clouddrive/share/O5q4XFaXKJGdt0YnqFTPwB7eDkhJacex9blIPvd9KP3

In engineering, the two vectors are calculated like in Pythagoras. I assume that is nothing new to you. The resulting Hypotenuse is the direction of the gondola here.
So, your idea of increasing the Gravity here is setting up a longer vertical vector to get a different angle for the gondola. Look at the swing-ride-carrusel, the empty chairs are not flying higher.

All the best

Hi Dr. Sassi,

Awesome! This is exactly what I was looking for, I would’ve never thought of that!

Thank you so much for your help!

Thank you,
Chris

You’re very welcome, Chris.

My best wishes for your project.

Hi Dr. Sassi,

As a follow-up to yesterday, I incorporated your setup into my carousel, and all works perfectly.
However, at frame 300, the gondolas start wobbling all of sudden.
Could this have to do with a sudden collision?
Do I need to set a certain angular limit to prevent this?

Thank you again in advance,
Chris

Here is the link: https://www.dropbox.com/s/86qbe71ygk6o8z6/Troika S24 v3.c4d?dl=0

Hi Chris,

Thanks a lot for the file and for using Dropbox; very much appreciated.

Several axes of motion, while adding tons of child objects, will create here a significant complexity. I placed a camera on a single-arm to see in a calm way what happens.
The Connector seems to start to wiggle. Even replacing the connector-related objects to take the plain axis of the object is not helping.

Let’s start with the most straightforward fix; perhaps that is already visually pleasing.

Go to the Timeline (DopeSheet), click on the first filmstrip icon (de-activate), and then on the next object’s filmstrip to enable it. This takes the main arm (Es ist der Hauptarm im Projekt) out of the equation and reduces the complexity considerably.

Now, Dynamic Tag> Cache> Bake All.

With this now stable and stored, switch on the filmstrip, and with it, the animation for the complete model is active again.
Is that sufficient for you?

I have explored this with a simplified model, and it works, as far I can tell. This means to me, that I would create for your model a simple pair of objects and place it in the Dynamic Tags> Collision> Shape> Another Object. Scene 03

Files 01-03

All the best

Thank you Dr. Sassi, that is very helpful.
I very much appreciate all your input on this!

You’re very welcome, Chris.

Thanks for your questions, I certainly have a win from every question, and I hope the forum has so as well.

Cheers