Commit Graph

13 Commits

Author SHA1 Message Date
erwin coumans
645a88176d Enable softness for btRigidBody contacts. This is implemented by some value (CFM, constraint force mixing) to the main diagonal of A.
CFM for contacts use world CFM value by default, and can override with custom CFM value using the
BT_CONTACT_FLAG_HAS_CONTACT_CFM stored in m_contactPointFlags.
Boolean m_lateralFrictionInitialized is replaced 'BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED' flag stored in int m_contactPointFlags in btManifoldPoint.
Enable successive over-relaxation parameter (SOR) for contacts. btMLCPSolver uses global CFM.
In one of the next commits, contact softness will be enabled btMultiBody contacts.
Also need to review use of CFM in btMLCPSolvers (only world CFM is used at the moment)
2016-01-22 17:43:36 -08:00
Erwin Coumans
193e680790 _N -> n, _C -> c, _L ->l, some collision with a standard C++ header? 2015-02-20 13:51:24 -08:00
Erwin Coumans
af5883c6e8 remove a lot of warnings (more todo in demos and serialization code) 2014-08-22 10:29:05 -07:00
erwin coumans
dfa738c13a Properly propagate the applied impulse for the MLCP solvers, so it will be available for contact and non-contact constraints.
Use real-time clock in AllBullet2Demos, rather than hard-coded 1./60.
2014-02-24 13:24:49 -08:00
erwin.coumans@gmail.com
218d4d1394 use a separate default cfm for the MLCP solver, it is a very sensitive value for Dantzig (and Lemke) 2013-10-31 16:52:32 +00:00
erwin.coumans@gmail.com
644d01d231 added the btNNCGConstraintSolver, based on the paper "Nonsmooth Nonlinear Conjugate Gradient Method for interactive
contact force problems". The solver needs a lot of iterations, before the quality goes up (~ 1000)
Thanks to Gabor PUHR for the contribution!
Improved the btLemkeSolver.
Remove the sparse optimizations from the btMatrixX.h, replace it with explicit call to rowComputeNonZeroElements (only used in the btSolveProjectedGaussSeidel), it was likely slowing things down, without being useful.
Re-enable SIMD in the solver (was accidently disabled in Bullet 2.82 release)
2013-10-31 06:17:08 +00:00
erwin.coumans@gmail.com
6ca948e22f make Lemke work with lower/upper bounds, using the BLCP to LCP conversion (using a dog-slow matrix inversion etc)
for this conversion, see also https://github.com/erwincoumans/num4lcp/blob/master/matlab/test_lcp_bounds.m and
appendix A1 in http://www.cs.duke.edu/~parr/nips10.pdf, thanks to Kenny Erleben and Evan Drumwright for the tips!
(friction is not coupled to normal forces yet)
2013-10-30 00:02:13 +00:00
erwin.coumans
1a2c3c0ee9 Added a Lemke MLCP solver, extracted from the MBSim project, and re-licensed under the zlib license
with permission of the original author. 
The Lemke implementation is not fully working yet:
1) we need to convert the lo-high LCP problem into a problem without the lo/high
2) we need to sort out the remaining instabilities, and report a failure if the max loopcount is reached etc.
We replaced the fmatvec library with our own LinearMath/btMatrixX.h, and STL std::vector with btAlignedObjectArray

Removed some warnings/potential issues: use fuzzyZero instead of isZero, and some warnings, 
related to this issue 756
2013-10-26 18:45:25 +00:00
erwin.coumans@gmail.com
19f999ac08 fix double precision, and remove alloca
increase mass of the load, to show benefits of direct MLCP solver
move damping back to original location
2013-10-24 18:31:27 +00:00
erwin.coumans@gmail.com
a1c962192c Allow the ForkLiftDemo to toggle between MLCP and SI solver, using F6 key.
Apply patch for CMake config, see Issue 754 (Issue 753)
Fix a few issue with the MLCP solver: allow split impulse, and fix offset in friction dependencies
2013-10-23 23:35:13 +00:00
erwin.coumans@gmail.com
5e372d6ac5 fix compile errors 2013-10-21 23:33:01 +00:00
erwin.coumans@gmail.com
379f0079e0 Added Dantzig MLCP solver option from Open Dynamics Engine (trying to avoid naming/linking conflicts in case ODE and Bullet is used together)
If an MLCP solver fails, use PGS/SI fallback, add a boolean return value for 'solve' method
2013-10-21 23:27:09 +00:00
erwin.coumans@gmail.com
1ca0493dc4 Build full A matrix and b vector for a MLCP solver interface, to explore Lemke, Dantzig, Newton and other MLCP solvers. The A matrix contains sparsity information.
Added a PGS solver that uses the sparsity of the A matrix, just for testing (the equivalent sequential impulse solver is much faster, not having to allocate the big matrices)
2013-10-20 17:38:14 +00:00