Apr 29, 2013 at 1:00pm

Dear max-forum-members,

after finishing the jit.phys-introduction I have been working on a virtual Newton’s Cradle with more than two spheres.

Unfortunately, the behaviour of my Newton’s Cradle is not yet realistic. I would be interested to learn more about why this is the case and what I can do in oder to get a more realistic behaviour. E.g., I have observed that the behaviour is more realistic if there is a small space between the spheres.

I’d appreciate any hints on how to get the cradle to behave more realistic.

Best regards,
Hanna

###### Attachments:
1. theworld.js
#68004
Apr 30, 2013 at 9:52am

Hi Rob,

thank you for your quick reply. I have implemented the hinge-locking-and-unlocking like in the example. While this helps with two spheres, I don’t seem to be able to get good results with more than two spheres…

I implemented it like this:
for every collision:
- get the two colliding spheres
- find out which one had the higher absolute x-direction velocity on impact
- lock that one for a specified amount of time

Hanna

###### Attachments:
1. theworld.js
#244360
May 1, 2013 at 9:04am

Hi Rob,

thanks again for your suggestion. I implemented the “locking the middle hinges” and right now, it gives funny results. But I guess it can be tuned. (I have not implemented the hack with passing the impulse to the opposite ball) yet.

Alternatively, I made an option that for every collision
* the hitting sphere is A
* the hit sphere is B
- passes on the velocity of A to B
- places A at its resting position
- sets A’s velocity to zero.

This looks a bit jumpy but it is rather realistic. Is there a way to naturally move the sphere to its resting position rather than just ‘teleporting’ it there?

Both options are in the updated patch, in case someone’s curious….

Cheers and thanks!
Hanna

###### Attachments:
1. theworld.js
#244362

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