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add 'fixed' joint for btMultiBody

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improve btMultiBody version of URDF reader (still work-in-progress)
enabled planar joint for btMultiBody (untested)
enable loading from relative path for .stl meshes
This commit is contained in:
erwin coumans
2014-08-28 18:42:08 -07:00
parent 3c558ec995
commit 89addd438e
19 changed files with 1276 additions and 304 deletions
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65
Demos/CommonMultiBodySetup.h
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@@ -7,6 +7,8 @@
#include "CommonPhysicsSetup.h"
#include "BulletDynamics/Featherstone/btMultiBodyDynamicsWorld.h"
#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
#include "BulletDynamics/Featherstone/btMultiBodyPoint2Point.h"
#include "BulletDynamics/Featherstone/btMultiBodyLinkCollider.h"
struct CommonMultiBodySetup : public CommonPhysicsSetup
{
@@ -21,9 +23,12 @@ struct CommonMultiBodySetup : public CommonPhysicsSetup
//data for picking objects
class btRigidBody* m_pickedBody;
class btTypedConstraint* m_pickedConstraint;
class btMultiBodyPoint2Point* m_pickingMultiBodyPoint2Point;
btVector3 m_oldPickingPos;
btVector3 m_hitPos;
btScalar m_oldPickingDist;
bool m_prevCanSleep;
CommonMultiBodySetup()
:m_broadphase(0),
@@ -32,7 +37,9 @@ struct CommonMultiBodySetup : public CommonPhysicsSetup
m_collisionConfiguration(0),
m_dynamicsWorld(0),
m_pickedBody(0),
m_pickedConstraint(0)
m_pickedConstraint(0),
m_pickingMultiBodyPoint2Point(0),
m_prevCanSleep(false)
{
}
@@ -157,9 +164,33 @@ struct CommonMultiBodySetup : public CommonPhysicsSetup
//very weak constraint for picking
p2p->m_setting.m_tau = 0.001f;
}
} else
{
btMultiBodyLinkCollider* multiCol = (btMultiBodyLinkCollider*)btMultiBodyLinkCollider::upcast(rayCallback.m_collisionObject);
if (multiCol && multiCol->m_multiBody)
{
m_prevCanSleep = multiCol->m_multiBody->getCanSleep();
multiCol->m_multiBody->setCanSleep(false);
btVector3 pivotInA = multiCol->m_multiBody->worldPosToLocal(multiCol->m_link, pickPos);
btMultiBodyPoint2Point* p2p = new btMultiBodyPoint2Point(multiCol->m_multiBody,multiCol->m_link,0,pivotInA,pickPos);
//if you add too much energy to the system, causing high angular velocities, simulation 'explodes'
//see also http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=4&t=949
//so we try to avoid it by clamping the maximum impulse (force) that the mouse pick can apply
//it is not satisfying, hopefully we find a better solution (higher order integrator, using joint friction using a zero-velocity target motor with limited force etc?)
btScalar scaling=1;
p2p->setMaxAppliedImpulse(2*scaling);
btMultiBodyDynamicsWorld* world = (btMultiBodyDynamicsWorld*) m_dynamicsWorld;
world->addMultiBodyConstraint(p2p);
m_pickingMultiBodyPoint2Point =p2p;
}
}
// pickObject(pickPos, rayCallback.m_collisionObject);
m_oldPickingPos = rayToWorld;
m_hitPos = pickPos;
@@ -177,18 +208,30 @@ struct CommonMultiBodySetup : public CommonPhysicsSetup
if (pickCon)
{
//keep it at the same picking distance
btVector3 newPivotB;
btVector3 dir = rayToWorld - rayFromWorld;
btVector3 dir = rayToWorld-rayFromWorld;
dir.normalize();
dir *= m_oldPickingDist;
newPivotB = rayFromWorld + dir;
btVector3 newPivotB = rayFromWorld + dir;
pickCon->setPivotB(newPivotB);
return true;
}
}
if (m_pickingMultiBodyPoint2Point)
{
//keep it at the same picking distance
btVector3 dir = rayToWorld-rayFromWorld;
dir.normalize();
dir *= m_oldPickingDist;
btVector3 newPivotB = rayFromWorld + dir;
m_pickingMultiBodyPoint2Point->setPivotInB(newPivotB);
}
return false;
}
virtual void removePickingConstraint()
@@ -200,6 +243,14 @@ struct CommonMultiBodySetup : public CommonPhysicsSetup
m_pickedConstraint = 0;
m_pickedBody = 0;
}
if (m_pickingMultiBodyPoint2Point)
{
m_pickingMultiBodyPoint2Point->getMultiBodyA()->setCanSleep(m_prevCanSleep);
btMultiBodyDynamicsWorld* world = (btMultiBodyDynamicsWorld*) m_dynamicsWorld;
world->removeMultiBodyConstraint(m_pickingMultiBodyPoint2Point);
delete m_pickingMultiBodyPoint2Point;
m_pickingMultiBodyPoint2Point = 0;
}
}