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Pancho
04-19-2005, 08:48 AM
Sounds pretty easy, eh?! I do have some success with using ClothFX (spring 5000000, sub 50000), but while floating on the ground after the first few bounces it doesn't rotate, just floats.

I tried HardFx before with SoftFx, but am a bit confused as the ball just bounces if the bounce/bind power of the collision plane is above 100%. Shouldn't this be a setting of the bounce object?

So, what's the best way to simulate a bouncing (tennis)ball that gets deformed when hitting the ground and gets back to its original shape when leaving the ground?

I'm using a tesselated sphere for the calculations.

Cheers
Pancho

Carm3D
04-19-2005, 09:27 AM
Try it with this ball.

Because it has an internal structure, you won't need such high sub structure. But you will need to add a clip-map so the 2-point polys don't render.

Pancho
04-19-2005, 11:00 AM
Thanks Carm,

nice idea and now it's easier to restore the original shape after a collission, but it's still not working 100%. The ball just doesn't bounce enough. Either it collapses if you play with the weight or other settings or it just sticks to the ground like a tomatoe. Again I realize that ClothFX is only a big compromise which works for some stuff, but in general needs a different approach to materials and their behaviour. Anybody else any experience?

What about HowardM or Cel, our FX gurus?

Cheers
Pancho

Celshader
04-19-2005, 07:52 PM
I tried HardFx before with SoftFx, but am a bit confused as the ball just bounces if the bounce/bind power of the collision plane is above 100%. Shouldn't this be a setting of the bounce object?

The points of the ball are bouncing off of the FX_Collision plane, so the FX_Collision plane's "Bounce/Bind" power controls the amount of the bounce.

Bounce/Bind = 100% -- the ball collides with the ground, but receives no rebound energy to bounce away. The points shouldn't bounce at all, then.

Bounce/Bind = 200% -- the ball collides with the ground and rebounds with 100% of its impact force. If it hits the ground at 1m/second, it will bounce away at 1m/second. Because the ball loses no energy with each rebound, the ball will never stop bouncing.

Bounce/Bind = 300% -- the ball collides with the ground and rebounds with 200% of its impact force. If it hits the ground at 1m/second, it will bounce away at 1m/second. Because the ball gains energy with each rebound, it'll bounce higher with each new collision. Kinda like that "Flubber" material in The Absent-Minded Professor.

Bounce/Bind = 150% -- the ball collides with the ground and rebounds with 50% of its impact force. If it hits the ground at 1m/second, it bounces away at 500mm/second. Because the ball loses half of its energy with each rebound, it should eventually appear to stop moving.

I'll see if I can take a crack at the ball later today.

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