Particle Collision

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Hello,

I'm doing the “particle sliding” video tutorial in H7.
Is it possible that when applying a collission on a surface, a few particles are going through the surface and NOT collide with it.

Why is this and what is a possible sollution?


Many thanks,


bernard
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Of the top of my head, you should be able to group a few particles (randomly or selectively) and then apply collisions to those grouped (or not grouped, depending on how you want). That should do it. Hopefully. :wink:

HTH,
Alex
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One of the more common reasons for particles not colliding is non-planar (read non-triangular) polygons in the collision geometry.

Another common problem is that the collision geometry is not static (ie. it is moving or deforming). In this case, you'll need to set the Hint parameter on the collision pop appropriately.

Sometimes collisions can be missed if a particle ends a timestep very very close to the surface. Increasing the collision tolerance on the collision pop can help eliminate this problem.

Finally, if your behaviour is set to bounce, you also have some corrective steps that the collision algorithm can attempt, which are found on the Constraints page on the collision pop.
Edited by - July 11, 2005 17:43:10
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Hello,



thanks for the great info!
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oops… appearantly I mis-read your question… sorry 'bout that.. ops:
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Also… if all else fails, crank up your oversampling from 1 to 2 or even 3 or 4, depending on how quickly your particles are moving. Increasing collision tolerance may resolve the issue but could cause particles to collide before they hit the surface. Oversampling forces your pops to compute in-between frames, so any particles which may be flying through your geometry between frames will be addressed.

Good luck!
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