- threading: adding btSequentialImpulseConstraintSolverMt
- task scheduler: added parallelSum so that parallel solver can compute residuals
- CommonRigidBodyMTBase: add slider for solver least squares residual and allow multithreading without needing OpenMP, TBB, or PPL
- taskScheduler: don't wait for workers to sleep/signal at the end of each parallel block
- parallel solver: convertContacts split into an allocContactConstraints and setupContactConstraints stage, the latter of which is done in parallel
- parallel solver: rolling friction is now interleaved along with normal friction
- parallel solver: batchified split impulse solving + some cleanup
- parallel solver: sorting batches from largest to smallest
- parallel solver: added parallel batch creation
- parallel solver: added warmstartingWriteBackContacts func + other cleanup
- task scheduler: truncate low bits to preserve determinism with parallelSum
- parallel solver: reducing dynamic mem allocs and trying to parallelize more of the batch setup
- parallel solver: parallelize updating constraint batch ids for merging
- parallel solver: adding debug visualization
- task scheduler: make TBB task scheduler parallelSum deterministic
- parallel solver: split batch gen code into separate file; allow selection of batch gen method
- task scheduler: add sleepWorkerThreadsHint() at end of simulation
- parallel solver: added grain size per phase
- task Scheduler: fix for strange threading issue; also no need for main thread to wait for workers to sleep
- base constraint solver: break out joint setup into separate function for profiling/overriding
- parallel solver: allow different batching method for contacts vs joints
- base constraint solver: add convertJoint and convertBodies to make it possible to parallelize joint and body conversion
- parallel solver: convert joints and bodies in parallel now
- parallel solver: speed up batch creation with run-length encoding
- parallel solver: batch gen: run-length expansion in parallel; collect constraint info in parallel
- parallel solver: adding spatial grid batching method
- parallel solver: enhancements to spatial grid batching
- sequential solver: moving code for writing back into functions that derived classes can call
- parallel solver: do write back of bodies and joints in parallel
- parallel solver: removed all batching methods except for spatial grid (others were ineffective)
- parallel solver: added 2D or 3D grid batching options; and a bit of cleanup
- move btDefaultTaskScheduler into LinearMath project
1) (win32window) don't convert char to wide, use char direct to window.
2) (CMakeLists) Don't link one library as static CPPLIB and no others (mismatched allocations)
3) (macros) Fix Gwen macros for mingw64 on windows build. (changes are by compiler(msc_ver) not platform)
4) (FileUtils) sprintf_s reference by platform, not compiler (mingw64 support)
5) (b3OpenCLUtils) fix bad define name _MSVC_VER->_MSC_VER
6) (compoundCollision) remove unused variables, simplify operation.
7) (impulseconstraint) remove duplicated code block
fix in indexing for maximal coordinates (unused by default, still experimental, requires many iterations for Minitaur due to extreme mass-ratio, hence use of reduces/generalized coordinates)
modify quadruped.py to test maximal coordinates
wrap angular servo (positional) target within [-PI,PI] in btGeneric6DofSpring2Constraint
add 'j' key to show body frames in wireframe/debug mode
Bullet C-API b3ChangeDynamicsInfoSetSpinningFriction/RollingFriction/Resitution
b3PhysicsParamSetRestitutionVelocityThreshold, / pybullet.setPhysicsEngineParameter restitutionVelocityThreshold:
if the velocity is below this threshhold, the restitution is zero (this prevents energy buildup at near-resting state)
pybullet restitution.py example.
implement friction anchors, position friction correction, disabled by default. Use colObj->setCollisionFlag(flag | CF_HAS_FRICTION_ANCHOR); See test/RobotClientAPI/SlopeFrictionMain.cpp. In URDF or SDF, add <friction_anchor/> in <contact> section of <link> to enable.
PhysicsServer: properly restore old activation state after releasing picked object
btMultiBodyConstraintSolver: disable flip/flop of contact/friction constraint solving by default (it breaks some internal flaky unit tests)
(for example solverInfo().m_leastSquaresResidualThreshold = 1e-7 and use large m_numSolverIterations
disable sphere-sphere contact cache, it is buggy (some contact point stay in the cache, when sphere penetrates more than total margins)
tweak some gpu demo settings
- fixing various race conditions throughout (usage of static vars, etc)
- addition of a few lightweight mutexes (which are compiled out by default)
- slight code rearrangement in discreteDynamicsWorld to facilitate multithreading
- PoolAllocator::allocate() can now be called when pool is full without
crashing (null pointer returned)
- PoolAllocator allocate and freeMemory, are OPTIONALLY threadsafe
(default is un-threadsafe)
- CollisionDispatcher no longer checks if the pool allocator is full
before calling allocate(), instead it just calls allocate() and
checks if the return is null -- this avoids a race condition
- SequentialImpulseConstraintSolver OPTIONALLY uses different logic in
getOrInitSolverBody() to avoid a race condition with kinematic bodies
- addition of 2 classes which together allow simulation islands to be run
in parallel:
- btSimulationIslandManagerMt
- btDiscreteDynamicsWorldMt
- MultiThreadedDemo example in the example browser demonstrating use of
OpenMP, Microsoft PPL, and Intel TBB
- use multithreading for other demos
- benchmark demo: add parallel raycasting
returns a pylist of contact points. Each point has the following data:
0 int m_contactFlags;//unused for now
1 int m_bodyUniqueIdA;
2 int m_bodyUniqueIdB;
3 int m_linkIndexA;
4 int m_linkIndexB;
5-6-7 double m_positionOnAInWS[3];//contact point location on object A, in world space coordinates
8-9-10 double m_positionOnBInWS[3];//contact point location on object A, in world space coordinates
11-12-13 double m_contactNormalOnBInWS[3];//the separating contact normal, pointing from object B towards object A
14 double m_contactDistance;//negative number is penetration, positive is distance.
15 double m_normalForce;
Added demos for rigid and multi body soft (compliant) contact.
Will also add simplified Hertz compliant contact, by dynamically modifying the ERP/CFM to mimic a non-linear spring.
Note that btManifoldPoint is growing too big, we need to implement proper contact constraints derived from btTypedConstraint.
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)
