The original version was written by Stephen Thompson.
I replaced Eigen math by Bullet LinearMath, and added a dedicated 6x6 matrix solver.
Also I integrated support for collisions/contact constraints between btMultiBody and btRigidBody, and de-activation support.
See Demos/FeatherstoneMultiBodyDemo/Win32FeatherstoneMultiBodyDemo.cpp for example usage.
There is currently only support for contact constraints for btMultiBody.
Next on the list will be adding support for joint limit constraint for btMultiBody.
The implementation is still experimental/untested, the quality will improve in upcoming Bullet releases.
Add speculative contact restitution, but disabled by default, not well tested (btDiscreteDynamicsWorld::setApplySpeculativeContactRestitution)
Add --with-double-precision option to premake build system
Note that it can easily introduce instability at regular (60Hertz) simulation steps so it is generally best to not use the option.
If needed, use a very small internal step, such as 1000 Hertz (world->stepSimulation(dt,100,1./1000.f); or stepSimulation(1./1000.,0);
(make sure to merge islands based on those predictive contacts too, added some check in the solver)
This fixes Issue 356.
Use same solver settings for AllBulletDemos
Make sure to embed the setCcdSweptSphereRadius inside the actual collision shape (for shoot box)
This should improve 'ccd' handling when using world->getDispatchInfo().m_useContinuous = true;body->setCcdSquareMotionThreshold(...); body->setCcdSquareMotionThreshold(...)
shoot smaller boxes (test)
use yellow instead of orange for contact point normals
tweak default erp and erp2 values, now split impulse is on by default (need to check it)
warmstarting for contact points was broken, fix in btPersistentManifold
enable split impulse by default (at the cost of some performance)
add the option for zero-length friction (instead of recomputing friction directions using btPlaneSpace), use the solver mode flag SOLVER_ALLOW_ZERO_LENGTH_FRICTION_DIRECTIONS
precompute lateral friction directions (in btManifoldResult)
remove the mConstraintRow[3] from btManifoldPoint, it just took a lot of memory with no benefits: fixed it in btParallelConstraintSolver
For OSX:
cd build
./premake_osx xcode4
for iOS:
cd build
./ios_build.sh
./ios_run.sh
Also integrated the branches/StackAllocation to make it easier to multi-thread collision detection in the near future. It avoids changing the btCollisionObject while performing collision detection.
As this is a large patch, some stuff might be temporarily broken, I'll keep an eye out on issues.
fix in infinite recursion in quickSort, exclude the pivot in each sub partition
disabled constraints don't merge simulation islands, and they don't disable collision between linked rigid bodies either.
If you need tunneling prevention, one option is to use the CCD motion clamping in btDiscreteDynamicsWorld. See also Bullet/Demos/CcdPhysicsDemo.
You can use an embedded sphere that prevents tunneling, using the following settings:
body->setCcdMotionThreshold(0.5);
body->setCcdSweptSphereRadius(0.9f);
Add a camera zoom setting for the demos, thanks to ejtttje, fixes Issue 543
use btConvexPolyhedron for debug rendering, if available
fixes in btConvexConvexAlgorithm for polyhedral contact clipping, if GJK separating normal is zero
don't shift vertices in btPolyhedralConvexShape
Avoid crash in BulletWorldImporter, ignoring 'invalid' constraints between two static bodies
Use a bitfield for btCollisionObject::CollisionObjectTypes (to allow custom types that are derived from build-in types such as btRigidBody)
Revert/improve softbody debug rendering
improve serialization based on feedback: make it easier to serialize a single object, or single shape, or single bvh.
Modified Bullet/Demos/ConcaveDemo to use btSerializer to serialize the btOptimizedBvh (or optionally the trimesh+bvh)
You can also serialize trimesh without BVH, use:
serializer->setSerializationFlags(BT_SERIALIZE_NO_BVH);// or BT_SERIALIZE_NO_TRIANGLEINFOMAP
