Can I set damping value for collided vertices?
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apapaxionga
- Posts: 19
- Joined: Mon Jul 14, 2014 9:05 pm
Can I set damping value for collided vertices?
In deformable object simulation, I want to set large damping for the collided vertices only. How can I do that?
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drleviathan
- Posts: 849
- Joined: Tue Sep 30, 2014 6:03 pm
- Location: San Francisco
Re: Can I set damping value for collided vertices?
The easiest way to do this would be to modify the restitution and/or friction of the objects that are colliding.
The restitution is a coefficient in the range [0,1] that modifies the amount of kinetic energy that is preserved in the relative frame during impact and can be set on a per-object basis. A value of zero means all of the relative kinetic energy is absorbed (like a bean-bag) whereas a value of 1 means all of the kinetic energy is conserved (like a bouncy ball).
Note that if two objects collide and one has a restitution of 0 and the other has 1 then some combined or average restitution is used for that collision (I think -- I'm too lazy to look at the code this morning).
Friction is different -- it determines how slippery an object is during impact. It can affect damping of tangential kinetic energy during collisions but has more to do with forces than energy. I think friction can range from 0 (slippery) to values larger than 1 (sticky), but there is probably an upper limit to how large it can be set (since otherwise the simulation would become unstable).
The restitution is a coefficient in the range [0,1] that modifies the amount of kinetic energy that is preserved in the relative frame during impact and can be set on a per-object basis. A value of zero means all of the relative kinetic energy is absorbed (like a bean-bag) whereas a value of 1 means all of the kinetic energy is conserved (like a bouncy ball).
Note that if two objects collide and one has a restitution of 0 and the other has 1 then some combined or average restitution is used for that collision (I think -- I'm too lazy to look at the code this morning).
Friction is different -- it determines how slippery an object is during impact. It can affect damping of tangential kinetic energy during collisions but has more to do with forces than energy. I think friction can range from 0 (slippery) to values larger than 1 (sticky), but there is probably an upper limit to how large it can be set (since otherwise the simulation would become unstable).