Cineversity

Hello,
In my project, I’m trying to ‘tie’ a balloon to a Cube with a cord. I want the balloon to blow around but to never extend beyond the length of the cord that is connecting it to the Cube.

To blow the balloon around, I’m using a Dynamics Body tag and a Wind object. I’m connecting the balloon to the Cube with a Spline that has a Spline Dynamics tag. How can I tether the balloon to the Cube with the spline? Again, I don’t want the spline to extend. When the cord has reached its farthest extension, I want the balloon to stop moving in that direction and react as a balloon would, physically.

Here is as far as I’ve gotten with my scene file:
https://drive.google.com/file/d/1RKSIMyHykl83w5lUAAXvyG7vtwbs8RNA/view?usp=sharing

Thank you!

Hi blastframe,

Thanks for the file.

Here is your file back:
https://www.amazon.com/clouddrive/share/iQRgmXXtcGXybcyBvJBVpSe2V5ah18VSFXQN17UgmAv

I hope that works for you. Please note that it is cached, and I find it essential to be cached.

Have a great weekend

Thank you, Dr. Sassi! That’s great. What is the advantage of using two Springs over one? Is it to get bending in the top half of the Spline?

Thanks for the reply, blastframe.

If you had one spring only, the rope would always be straight. When you observe balloons, they have very little stability. The slightest wind shows that the string is affected by the wind as well. With the tiny cube in the middle, the rope looks more natural to me.

As usual, I play with the files a little bit, double-checked again if I missed something. You might find some changes here:
https://www.amazon.com/clouddrive/share/jM1rxymTHPFbYlom5AWmZJbdLBv1lozTlFc1D79YK2n

The main one would be the rotational mass and dampening.

My best wishes

That is gorgeous! That made a huge difference in appeal. If I need to make adjustments to the Wind strength, is there an order for the caching (e.g. Cube.1 first, then Balloon)? How do I edit the positions of the Cubes? Things get a little crazy if I move Cube.1.

Thanks again, blastframe.

I typically start with the Cache All. It usually sorts itself out. Perhaps, because I try always to see what information is given first, then second, etc. Top to bottom in the Object Manager, whereby we can undoubtedly argue if the springs should be above or below the three dynamic objects.

Keep an eye on the Force parameter of the cube.1, lift and drag if you change something.

So, I call it a night. It was a long week.

Enjoy.

Thank you, Dr. Sassi! Enjoy the weekend!

You too, blastframe, thanks!