Ball/Racket impact deformation dynamics


#1

Hi all,
First of all I´m new posting in the forum but have been browsing and looking for solutions many times before. THanks for all the great tips and information. Sorry if its been posted or discussed before but I can´t seem to find it if it has. Thanks in advance for any suggestions/opinions you cool people may send my way.
I have the following issue, I need to show, in slow motion, the impact between a ball and a racket (paddel tennis), showing both deformations (ball squish and racket inward dent) and then as the ball shoots away from the racket both objects get back to the original forms. Ive been trying to do it with dynamics so that I can use the cool time mapping for the slow motion. The ball deformation with a soft body tag isnt the issue to be honest, my isssue is how to do it for the racket with a simulation tag. I know I could fake it without dynamics and use an FDD deformer on the racket just as the ball hits but the result wont be as organic. The mesh for the racket is pretty dense and I think it all about the rigid/soft body tag parameters to get it to bend inward a little bit because of the impact. Maybe I just need to add some sort of spherical field to the ball so that it deforms the racket as it hits it or something like that. Sorry for my ignorance!
I did a test with an FDD on the racket just to give you an idea of the sort of deformation Im looking for on the racket but I cant post them since I am a new user :disappointed_relieved: I could link some screenshots and the project file but I dont know how I can yet. If anybody could help me out I would greatly appreciate it.

Thanks again and sorry if this has been posted on the wrong topic or talked about before.

Take care,
Juan


#2

I don’t think your case is something that the dynamics system was designed to solve.
(That is showing collision micro deformations)

If I were you I would try the Collision Deformer for the racket net and if it is too dense to work with try out the Mesh Deformer. You might need to use a proxy for the tennis ball to have the right tension deformation.
As for the rackets’ small and fast vibration after the ball has deflected maybe some MoGraph Effector with oscillation abilities (sound maybe?) - they have a deformer mode you can use on objects.


#3

Here’s my version …
Use magnet on the net and then sinc ball to the movement
of the net using squash and stretch.

Only took 30 clicks to post

:persevere:https://forums.cgsociety.org/uploads/default/original/3X/9/d/9d5dad5e83ec41a039a86675de59dd06f1edd85d.mov


#4

Thanks for the reply! Im also not sure I can solve it with dynamics without going crazy with render times and rigid body tag parameters. The collision deformer/mesh deformer might do the trick and make things more simple. I will have to “simulate” the whole ball/racket interaction though which I was hoping I didnt have to do. The whole impact/slowmo would be more real/organic with dynamics but I may indeed have to skip it. I may try something like Sean Dove did on his “Collision object” tutorial, although the racket has to be more rigid and less bouncy as the floor on his example.

I will post back if it works!

If you think of anything else let me know.

Thanks again!


#5

I haven’t used the Jiggle Deformer before… theoretically it could help with the vibrations…
I haven’t used a tennis racket either and don’t know the composition of the net. I’m a badminton player and know about the shuttle racket and its reactions though. I expect they are similar.

There is a very small, highly reduced tension wave. No vibration from the rackets body as I falsely expected though. I guess tennis players have a very strong grip overpowering all force from the ball.

So this is a fairly easy keyframe animation with many deformers.


#6

Thank you again! Thats a great idea for the net vibration but Im actually working with a “Paddle Tennis” racket which doesnt have a net, its “solid” with some holes.

![Racket_FDD3|690x461]
So there wouldnt be the same ripple effect as with the net.

But I will try the collision deformer for the racket and maybe squash/strech with the ball. I will let you know how it goes.

If anyone else has another idea let me know!

Take care mate!