Help Bouncy Ropes?

[josemendez]

Hi,

me again. After my previous two posts which were related to making a wobbly weiner (for anyone with a similar endeavour here are the links: http://obi.virtualmethodstudio.com/forum...-3690.html & http://obi.virtualmethodstudio.com/forum...-3693.html) I now want my weiner to also be bouncy. 

Sounds weird I know but the behaviour I want to achieve is to have it bounce of a floor it is hitting .... 

Well. The only Idea I had was to change the stickiness of my collision material to a negative value (I tried -1) and set the stick distance to something arger than 0 (I tried 0.1). That way (according to the drawing in the article here http://obi.virtualmethodstudio.com/manua...rials.html) a bouncy behaviour should occur - in my mind.

You guessed it right, it does not. Am I doing something wrong or is that behaviour not achievable with Obi Rope?

Best, 

Robert

Hi!

Not achievable in Obi, at least not out of the box. This technical term for this is called "restitution" or "elastic collision response". Collisions in Obi are perfectly inelastic because cloth, ropes and fluid have zero restitution in the real world (they're not bouncy at all), and softbodies have their own restitution built-in since they're soft and tend to bounce automatically.

You can't approximate this using negative sticking. One -slightly complex- way of implementing it would be to subscribe to contact callbacks, and then modify the velocity of particles involved in a contact, increasing it by some amount in the direction of the contact normal. See:
http://obi.virtualmethodstudio.com/manua...sions.html

I will look into adding built-in support for restitution in the future, should be doable.

kind regards,