blow up a balloon (fill it with air)

[Pim]

I like to make an animation inwhich a balloon is filled with air. Is that possible?
Also, I like the balloon then to stick to a rope and when the rope is moved the balloon also moves.
I am using 2024.0.2

I have seen some totorials doing this for previous versions using Spline Dynamics, which in 204 is now Rope functionality.
I have problems connecting and moving the rope and the balloon together.

[Dr. Sassi]

Hi Pim,

Elly showed here how to inflate a balloon-shape
https://www.youtube.com/live/ccIM7cbp-yk?si=eUOkbbT3KckCJIRP&t=1390
IF you want to see the result:
https://www.youtube.com/live/ccIM7cbp-yk?si=ia4_YlUeP7qok69B&t=1761

Chris Schmidt
https://youtu.be/G8cL9zZrMYw?si=Xl-6w_2m8sU_HkiA&t=2745

The Rope would need a Rope Belt and a Rope Tag
https://help.maxon.net/c4d/en-us/?_gl=11gs7l3o_gcl_au*MTEyOTU1NDkzMC4xNjk2NTI5NTg0#html/THAIRCONSTRAINT.html?TocPath=Object%2520Manager%257CTags%2520Menu%257CSimulation%2520Tags%257CRope%2520Belt%2520Tag%257C_____0
Example:
CV4_2024_drs_23_SIbr_01.c4d

All the best

[Pim]

Thank you.
Also the link in the email is very interesting.
Chris Schmidt showed here how to inflate a balloon-shape
https://youtu.be/G8cL9zZrMYw?si=Xl-6w_2m8sU_HkiA&t=2745

So, I will model a balloon by taking a Sphere with a Taper and then inflate it.

[Dr. Sassi]

Thank you, Pim.

I was unsure which link to use, but perhaps having both is OK.

I know that the Dynamics/Simulation and the Balloon option is tempting, but I love to have more control. I love to use Simulation, but what is needed in a project depends. I often use both for prep and later; the manual animation takes over.

Here is my sketch:

CV4_2024_drs_23_ANbf_01.c4d

(The prep is available: Layers)

I modeled a balloon and then used Cloth to deflate it.
With the original shape, I created a PoseMorph, which allows me to inflate it at once, or with a PoseMoprh Deformer, like a hot air balloon.

From there, I animated it and put a rope on it.

That might look old school, but Dynamics/Simulation need the freedom to look well, and to art-direct them takes time, and the danger is there that you fight what was supposed to help you.

I started with the Balloon Simulation and put a Tag on it, "blow it up" ;-), but it is a joke that the client stops requesting changes when the deadline has passed. Or not.
So, the idea of having it completely under control is often the faster way during a project.

But it always depends. If I had put all questions from the past twenty years for a balloon with a rope in a collection, each would be different.
There is no one-size-fits-all, and I would love to see a storyboard first, then answer.

Enjoy your project

[Pim]

I added a second Rope Belt at the beginning of the spline connected to a Null "Move point".
So now, when I move this Null, the balloon should follow the Spline Rope.
However, this is now happening, the balloon stays in one place.
Also the length of the spline seems to change.
What am I doing wrong?

balloon met cloth v02.c4d

[Dr. Sassi]

Hi Pim,

Keyframes move the Balloon in the scene that its parent Null has; it is not a Simulation.

I have no idea how to keep the length of a Rope the same. I was in a more extended session with some other Master Trainers and asked, as I thought I might have missed something. The answer was that it is not a feature in the Simulation system. An indicator that it is not fully developed is perhaps that it has so far no connectors, like Springs, that I usually use for balloons and similar setups, see below (And yes, the string is behind. This needs to be baked and adjusted.

CV4_2024_drs_23_BUbr_01.c4d

I would animate the Balloon as needed and the rope's end, then connect the two. But that is just me.

All the best