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is soft_cfm and soft_erp utilized by ODE

asked 2016-07-03 17:04:10 -0600

lonewolf gravatar image

updated 2016-07-03 17:05:04 -0600

I have been trying to add some softness for my grasping ball experiment and I have been struggling to get anywhere. I have been fiddling around with soft_cfm and soft_erp values.

But if you look at physics/ode/ODEPhysics.cc, you can see that the values for soft_cfm is calculated using the kp and kd, so does the value of soft_cfm and soft_erp have any affect?

// Compute the CFM and ERP by assuming the two bodies form a
  // spring-damper system.
  double kp = 1.0 / (1.0 / surf1->kp + 1.0 / surf2->kp);
  double kd = surf1->kd + surf2->kd;

  contact.surface.soft_erp = (this->maxStepSize * kp) /
                             (this->maxStepSize * kp + kd);

  contact.surface.soft_cfm = 1.0 / (this->maxStepSize * kp + kd);

  // contact.surface.soft_erp = 0.5*(_collision1->surface->softERP +
  //                                _collision2->surface->softERP);
  // contact.surface.soft_cfm = 0.5*(_collision1->surface->softCFM +
  //                                _collision2->surface->softCFM);
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answered 2017-04-11 08:02:28 -0600

eugene-katsevman gravatar image

updated 2017-04-11 16:18:10 -0600

They seem to be not used at all, kp and kp are used instead, so you're right. I don't know why they are there

UPD: they were used back in 2012

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Asked: 2016-07-03 17:04:10 -0600

Seen: 1,350 times

Last updated: Apr 11 '17