Bullet Collision Detection & Physics Library
btRigidBody.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
16 #include "btRigidBody.h"
18 #include "LinearMath/btMinMax.h"
23 
24 //'temporarily' global variables
26 bool gDisableDeactivation = false;
27 static int uniqueId = 0;
28 
30 {
31  setupRigidBody(constructionInfo);
32 }
33 
34 btRigidBody::btRigidBody(btScalar mass, btMotionState* motionState, btCollisionShape* collisionShape, const btVector3& localInertia)
35 {
36  btRigidBodyConstructionInfo cinfo(mass, motionState, collisionShape, localInertia);
37  setupRigidBody(cinfo);
38 }
39 
41 {
43 
46  m_angularFactor.setValue(1, 1, 1);
47  m_linearFactor.setValue(1, 1, 1);
48  m_gravity.setValue(btScalar(0.0), btScalar(0.0), btScalar(0.0));
52  setDamping(constructionInfo.m_linearDamping, constructionInfo.m_angularDamping);
53 
56  m_optionalMotionState = constructionInfo.m_motionState;
59  m_additionalDamping = constructionInfo.m_additionalDamping;
64 
66  {
68  }
69  else
70  {
71  m_worldTransform = constructionInfo.m_startWorldTransform;
72  }
73 
77 
78  //moved to btCollisionObject
79  m_friction = constructionInfo.m_friction;
80  m_rollingFriction = constructionInfo.m_rollingFriction;
81  m_spinningFriction = constructionInfo.m_spinningFriction;
82 
83  m_restitution = constructionInfo.m_restitution;
84 
85  setCollisionShape(constructionInfo.m_collisionShape);
87 
88  setMassProps(constructionInfo.m_mass, constructionInfo.m_localInertia);
90 
92 
98 }
99 
101 {
103 }
104 
106 {
107  //todo: clamp to some (user definable) safe minimum timestep, to limit maximum angular/linear velocities
108  if (timeStep != btScalar(0.))
109  {
110  //if we use motionstate to synchronize world transforms, get the new kinematic/animated world transform
111  if (getMotionState())
113  btVector3 linVel, angVel;
114 
119  //printf("angular = %f %f %f\n",m_angularVelocity.getX(),m_angularVelocity.getY(),m_angularVelocity.getZ());
120  }
121 }
122 
123 void btRigidBody::getAabb(btVector3& aabbMin, btVector3& aabbMax) const
124 {
125  getCollisionShape()->getAabb(m_worldTransform, aabbMin, aabbMax);
126 }
127 
128 void btRigidBody::setGravity(const btVector3& acceleration)
129 {
130  if (m_inverseMass != btScalar(0.0))
131  {
132  m_gravity = acceleration * (btScalar(1.0) / m_inverseMass);
133  }
134  m_gravity_acceleration = acceleration;
135 }
136 
137 void btRigidBody::setDamping(btScalar lin_damping, btScalar ang_damping)
138 {
139 #ifdef BT_USE_OLD_DAMPING_METHOD
140  m_linearDamping = btMax(lin_damping, btScalar(0.0));
141  m_angularDamping = btMax(ang_damping, btScalar(0.0));
142 #else
143  m_linearDamping = btClamped(lin_damping, btScalar(0.0), btScalar(1.0));
144  m_angularDamping = btClamped(ang_damping, btScalar(0.0), btScalar(1.0));
145 #endif
146 }
147 
150 {
151  //On new damping: see discussion/issue report here: http://code.google.com/p/bullet/issues/detail?id=74
152  //todo: do some performance comparisons (but other parts of the engine are probably bottleneck anyway
153 
154 #ifdef BT_USE_OLD_DAMPING_METHOD
155  m_linearVelocity *= btMax((btScalar(1.0) - timeStep * m_linearDamping), btScalar(0.0));
156  m_angularVelocity *= btMax((btScalar(1.0) - timeStep * m_angularDamping), btScalar(0.0));
157 #else
158  m_linearVelocity *= btPow(btScalar(1) - m_linearDamping, timeStep);
160 #endif
161 
163  {
164  //Additional damping can help avoiding lowpass jitter motion, help stability for ragdolls etc.
165  //Such damping is undesirable, so once the overall simulation quality of the rigid body dynamics system has improved, this should become obsolete
168  {
171  }
172 
173  btScalar speed = m_linearVelocity.length();
174  if (speed < m_linearDamping)
175  {
176  btScalar dampVel = btScalar(0.005);
177  if (speed > dampVel)
178  {
180  m_linearVelocity -= dir * dampVel;
181  }
182  else
183  {
185  }
186  }
187 
188  btScalar angSpeed = m_angularVelocity.length();
189  if (angSpeed < m_angularDamping)
190  {
191  btScalar angDampVel = btScalar(0.005);
192  if (angSpeed > angDampVel)
193  {
195  m_angularVelocity -= dir * angDampVel;
196  }
197  else
198  {
200  }
201  }
202  }
203 }
204 
206 {
208  return;
209 
211 }
212 
214 {
216  return;
217 
219 }
220 
222 {
223  setCenterOfMassTransform(newTrans);
224 }
225 
226 void btRigidBody::setMassProps(btScalar mass, const btVector3& inertia)
227 {
228  if (mass == btScalar(0.))
229  {
231  m_inverseMass = btScalar(0.);
232  }
233  else
234  {
236  m_inverseMass = btScalar(1.0) / mass;
237  }
238 
239  //Fg = m * a
241 
242  m_invInertiaLocal.setValue(inertia.x() != btScalar(0.0) ? btScalar(1.0) / inertia.x() : btScalar(0.0),
243  inertia.y() != btScalar(0.0) ? btScalar(1.0) / inertia.y() : btScalar(0.0),
244  inertia.z() != btScalar(0.0) ? btScalar(1.0) / inertia.z() : btScalar(0.0));
245 
247 }
248 
250 {
252 }
253 
255 {
256  btVector3 inertiaLocal;
257  const btVector3 inertia = m_invInertiaLocal;
258  inertiaLocal.setValue(inertia.x() != btScalar(0.0) ? btScalar(1.0) / inertia.x() : btScalar(0.0),
259  inertia.y() != btScalar(0.0) ? btScalar(1.0) / inertia.y() : btScalar(0.0),
260  inertia.z() != btScalar(0.0) ? btScalar(1.0) / inertia.z() : btScalar(0.0));
261  return inertiaLocal;
262 }
263 
264 inline btVector3 evalEulerEqn(const btVector3& w1, const btVector3& w0, const btVector3& T, const btScalar dt,
265  const btMatrix3x3& I)
266 {
267  const btVector3 w2 = I * w1 + w1.cross(I * w1) * dt - (T * dt + I * w0);
268  return w2;
269 }
270 
271 inline btMatrix3x3 evalEulerEqnDeriv(const btVector3& w1, const btVector3& w0, const btScalar dt,
272  const btMatrix3x3& I)
273 {
274  btMatrix3x3 w1x, Iw1x;
275  const btVector3 Iwi = (I * w1);
276  w1.getSkewSymmetricMatrix(&w1x[0], &w1x[1], &w1x[2]);
277  Iwi.getSkewSymmetricMatrix(&Iw1x[0], &Iw1x[1], &Iw1x[2]);
278 
279  const btMatrix3x3 dfw1 = I + (w1x * I - Iw1x) * dt;
280  return dfw1;
281 }
282 
284 {
285  btVector3 inertiaLocal = getLocalInertia();
286  btMatrix3x3 inertiaTensorWorld = getWorldTransform().getBasis().scaled(inertiaLocal) * getWorldTransform().getBasis().transpose();
287  btVector3 tmp = inertiaTensorWorld * getAngularVelocity();
288  btVector3 gf = getAngularVelocity().cross(tmp);
289  btScalar l2 = gf.length2();
290  if (l2 > maxGyroscopicForce * maxGyroscopicForce)
291  {
292  gf *= btScalar(1.) / btSqrt(l2) * maxGyroscopicForce;
293  }
294  return gf;
295 }
296 
298 {
299  btVector3 idl = getLocalInertia();
300  btVector3 omega1 = getAngularVelocity();
302 
303  // Convert to body coordinates
304  btVector3 omegab = quatRotate(q.inverse(), omega1);
305  btMatrix3x3 Ib;
306  Ib.setValue(idl.x(), 0, 0,
307  0, idl.y(), 0,
308  0, 0, idl.z());
309 
310  btVector3 ibo = Ib * omegab;
311 
312  // Residual vector
313  btVector3 f = step * omegab.cross(ibo);
314 
315  btMatrix3x3 skew0;
316  omegab.getSkewSymmetricMatrix(&skew0[0], &skew0[1], &skew0[2]);
317  btVector3 om = Ib * omegab;
318  btMatrix3x3 skew1;
319  om.getSkewSymmetricMatrix(&skew1[0], &skew1[1], &skew1[2]);
320 
321  // Jacobian
322  btMatrix3x3 J = Ib + (skew0 * Ib - skew1) * step;
323 
324  // btMatrix3x3 Jinv = J.inverse();
325  // btVector3 omega_div = Jinv*f;
326  btVector3 omega_div = J.solve33(f);
327 
328  // Single Newton-Raphson update
329  omegab = omegab - omega_div; //Solve33(J, f);
330  // Back to world coordinates
331  btVector3 omega2 = quatRotate(q, omegab);
332  btVector3 gf = omega2 - omega1;
333  return gf;
334 }
335 
337 {
338  // use full newton-euler equations. common practice to drop the wxIw term. want it for better tumbling behavior.
339  // calculate using implicit euler step so it's stable.
340 
341  const btVector3 inertiaLocal = getLocalInertia();
342  const btVector3 w0 = getAngularVelocity();
343 
344  btMatrix3x3 I;
345 
346  I = m_worldTransform.getBasis().scaled(inertiaLocal) *
348 
349  // use newtons method to find implicit solution for new angular velocity (w')
350  // f(w') = -(T*step + Iw) + Iw' + w' + w'xIw'*step = 0
351  // df/dw' = I + 1xIw'*step + w'xI*step
352 
353  btVector3 w1 = w0;
354 
355  // one step of newton's method
356  {
357  const btVector3 fw = evalEulerEqn(w1, w0, btVector3(0, 0, 0), step, I);
358  const btMatrix3x3 dfw = evalEulerEqnDeriv(w1, w0, step, I);
359 
360  btVector3 dw;
361  dw = dfw.solve33(fw);
362  //const btMatrix3x3 dfw_inv = dfw.inverse();
363  //dw = dfw_inv*fw;
364 
365  w1 -= dw;
366  }
367 
368  btVector3 gf = (w1 - w0);
369  return gf;
370 }
371 
373 {
375  return;
376 
379 
380 #define MAX_ANGVEL SIMD_HALF_PI
382  btScalar angvel = m_angularVelocity.length();
383  if (angvel * step > MAX_ANGVEL)
384  {
385  m_angularVelocity *= (MAX_ANGVEL / step) / angvel;
386  }
387  #if defined(BT_CLAMP_VELOCITY_TO) && BT_CLAMP_VELOCITY_TO > 0
388  clampVelocity(m_angularVelocity);
389  #endif
390 }
391 
393 {
394  btQuaternion orn;
396  return orn;
397 }
398 
400 {
401  if (isKinematicObject())
402  {
404  }
405  else
406  {
408  }
411  m_worldTransform = xform;
413 }
414 
416 {
418 
419  int index = m_constraintRefs.findLinearSearch(c);
420  //don't add constraints that are already referenced
421  //btAssert(index == m_constraintRefs.size());
422  if (index == m_constraintRefs.size())
423  {
425  btCollisionObject* colObjA = &c->getRigidBodyA();
426  btCollisionObject* colObjB = &c->getRigidBodyB();
427  if (colObjA == this)
428  {
429  colObjA->setIgnoreCollisionCheck(colObjB, true);
430  }
431  else
432  {
433  colObjB->setIgnoreCollisionCheck(colObjA, true);
434  }
435  }
436 }
437 
439 {
440  int index = m_constraintRefs.findLinearSearch(c);
441  //don't remove constraints that are not referenced
442  if (index < m_constraintRefs.size())
443  {
445  btCollisionObject* colObjA = &c->getRigidBodyA();
446  btCollisionObject* colObjB = &c->getRigidBodyB();
447  if (colObjA == this)
448  {
449  colObjA->setIgnoreCollisionCheck(colObjB, false);
450  }
451  else
452  {
453  colObjB->setIgnoreCollisionCheck(colObjA, false);
454  }
455  }
456 }
457 
459 {
460  int sz = sizeof(btRigidBodyData);
461  return sz;
462 }
463 
465 const char* btRigidBody::serialize(void* dataBuffer, class btSerializer* serializer) const
466 {
467  btRigidBodyData* rbd = (btRigidBodyData*)dataBuffer;
468 
469  btCollisionObject::serialize(&rbd->m_collisionObjectData, serializer);
470 
471  m_invInertiaTensorWorld.serialize(rbd->m_invInertiaTensorWorld);
472  m_linearVelocity.serialize(rbd->m_linearVelocity);
473  m_angularVelocity.serialize(rbd->m_angularVelocity);
474  rbd->m_inverseMass = m_inverseMass;
475  m_angularFactor.serialize(rbd->m_angularFactor);
476  m_linearFactor.serialize(rbd->m_linearFactor);
477  m_gravity.serialize(rbd->m_gravity);
478  m_gravity_acceleration.serialize(rbd->m_gravity_acceleration);
479  m_invInertiaLocal.serialize(rbd->m_invInertiaLocal);
480  m_totalForce.serialize(rbd->m_totalForce);
481  m_totalTorque.serialize(rbd->m_totalTorque);
482  rbd->m_linearDamping = m_linearDamping;
483  rbd->m_angularDamping = m_angularDamping;
484  rbd->m_additionalDamping = m_additionalDamping;
485  rbd->m_additionalDampingFactor = m_additionalDampingFactor;
486  rbd->m_additionalLinearDampingThresholdSqr = m_additionalLinearDampingThresholdSqr;
487  rbd->m_additionalAngularDampingThresholdSqr = m_additionalAngularDampingThresholdSqr;
488  rbd->m_additionalAngularDampingFactor = m_additionalAngularDampingFactor;
489  rbd->m_linearSleepingThreshold = m_linearSleepingThreshold;
490  rbd->m_angularSleepingThreshold = m_angularSleepingThreshold;
491 
492  // Fill padding with zeros to appease msan.
493 #ifdef BT_USE_DOUBLE_PRECISION
494  memset(rbd->m_padding, 0, sizeof(rbd->m_padding));
495 #endif
496 
497  return btRigidBodyDataName;
498 }
499 
501 {
502  btChunk* chunk = serializer->allocate(calculateSerializeBufferSize(), 1);
503  const char* structType = serialize(chunk->m_oldPtr, serializer);
504  serializer->finalizeChunk(chunk, structType, BT_RIGIDBODY_CODE, (void*)this);
505 }
const T & btMax(const T &a, const T &b)
Definition: btMinMax.h:27
const T & btClamped(const T &a, const T &lb, const T &ub)
Definition: btMinMax.h:33
btVector3 quatRotate(const btQuaternion &rotation, const btVector3 &v)
Definition: btQuaternion.h:926
bool gDisableDeactivation
Definition: btRigidBody.cpp:26
#define MAX_ANGVEL
btVector3 evalEulerEqn(const btVector3 &w1, const btVector3 &w0, const btVector3 &T, const btScalar dt, const btMatrix3x3 &I)
btScalar gDeactivationTime
Definition: btRigidBody.cpp:25
static int uniqueId
Definition: btRigidBody.cpp:27
btMatrix3x3 evalEulerEqnDeriv(const btVector3 &w1, const btVector3 &w0, const btScalar dt, const btMatrix3x3 &I)
#define btRigidBodyDataName
Definition: btRigidBody.h:36
#define btRigidBodyData
Definition: btRigidBody.h:35
@ BT_ENABLE_GYROSCOPIC_FORCE_IMPLICIT_BODY
Definition: btRigidBody.h:47
btScalar btPow(btScalar x, btScalar y)
Definition: btScalar.h:521
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:314
btScalar btSqrt(btScalar y)
Definition: btScalar.h:466
#define BT_RIGIDBODY_CODE
Definition: btSerializer.h:112
int size() const
return the number of elements in the array
int findLinearSearch(const T &key) const
void remove(const T &key)
void push_back(const T &_Val)
void * m_oldPtr
Definition: btSerializer.h:52
btCollisionObject can be used to manage collision detection objects.
bool isStaticOrKinematicObject() const
virtual const char * serialize(void *dataBuffer, class btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
btTransform & getWorldTransform()
btTransform m_worldTransform
virtual void setCollisionShape(btCollisionShape *collisionShape)
btVector3 m_interpolationLinearVelocity
void setIgnoreCollisionCheck(const btCollisionObject *co, bool ignoreCollisionCheck)
btVector3 m_interpolationAngularVelocity
int m_internalType
m_internalType is reserved to distinguish Bullet's btCollisionObject, btRigidBody,...
btTransform m_interpolationWorldTransform
m_interpolationWorldTransform is used for CCD and interpolation it can be either previous or future (...
bool isKinematicObject() const
The btCollisionShape class provides an interface for collision shapes that can be shared among btColl...
virtual void getAabb(const btTransform &t, btVector3 &aabbMin, btVector3 &aabbMax) const =0
getAabb returns the axis aligned bounding box in the coordinate frame of the given transform t.
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:50
btVector3 solve33(const btVector3 &b) const
Solve A * x = b, where b is a column vector.
Definition: btMatrix3x3.h:648
btMatrix3x3 transpose() const
Return the transpose of the matrix.
Definition: btMatrix3x3.h:1049
void getRotation(btQuaternion &q) const
Get the matrix represented as a quaternion.
Definition: btMatrix3x3.h:420
btMatrix3x3 scaled(const btVector3 &s) const
Create a scaled copy of the matrix.
Definition: btMatrix3x3.h:622
void serialize(struct btMatrix3x3Data &dataOut) const
Definition: btMatrix3x3.h:1401
void setValue(const btScalar &xx, const btScalar &xy, const btScalar &xz, const btScalar &yx, const btScalar &yy, const btScalar &yz, const btScalar &zx, const btScalar &zy, const btScalar &zz)
Set the values of the matrix explicitly (row major)
Definition: btMatrix3x3.h:204
The btMotionState interface class allows the dynamics world to synchronize and interpolate the update...
Definition: btMotionState.h:24
virtual void getWorldTransform(btTransform &worldTrans) const =0
The btQuaternion implements quaternion to perform linear algebra rotations in combination with btMatr...
Definition: btQuaternion.h:50
btQuaternion inverse() const
Return the inverse of this quaternion.
Definition: btQuaternion.h:497
void getAabb(btVector3 &aabbMin, btVector3 &aabbMax) const
btScalar m_additionalAngularDampingFactor
Definition: btRigidBody.h:80
void applyGravity()
const btVector3 & getAngularVelocity() const
Definition: btRigidBody.h:437
void integrateVelocities(btScalar step)
void addConstraintRef(btTypedConstraint *c)
virtual void serializeSingleObject(class btSerializer *serializer) const
btScalar m_linearDamping
Definition: btRigidBody.h:73
btMotionState * getMotionState()
Definition: btRigidBody.h:549
btMatrix3x3 m_invInertiaTensorWorld
Definition: btRigidBody.h:61
int m_frictionSolverType
Definition: btRigidBody.h:566
btVector3 m_invInertiaLocal
Definition: btRigidBody.h:69
void applyDamping(btScalar timeStep)
applyDamping damps the velocity, using the given m_linearDamping and m_angularDamping
btMotionState * m_optionalMotionState
Definition: btRigidBody.h:86
btVector3 m_gravity
Definition: btRigidBody.h:67
int m_contactSolverType
Definition: btRigidBody.h:565
void applyCentralForce(const btVector3 &force)
Definition: btRigidBody.h:274
virtual const char * serialize(void *dataBuffer, class btSerializer *serializer) const
fills the dataBuffer and returns the struct name (and 0 on failure)
btVector3 m_turnVelocity
Definition: btRigidBody.h:101
btScalar m_additionalDampingFactor
Definition: btRigidBody.h:77
virtual int calculateSerializeBufferSize() const
int m_rigidbodyFlags
Definition: btRigidBody.h:91
btScalar m_additionalAngularDampingThresholdSqr
Definition: btRigidBody.h:79
void setGravity(const btVector3 &acceleration)
btRigidBody(const btRigidBodyConstructionInfo &constructionInfo)
btRigidBody constructor using construction info
Definition: btRigidBody.cpp:29
btScalar m_linearSleepingThreshold
Definition: btRigidBody.h:82
btQuaternion getOrientation() const
void proceedToTransform(const btTransform &newTrans)
btVector3 m_linearFactor
Definition: btRigidBody.h:65
void saveKinematicState(btScalar step)
btVector3 getLocalInertia() const
btVector3 computeGyroscopicImpulseImplicit_World(btScalar dt) const
perform implicit force computation in world space
btVector3 m_angularFactor
Definition: btRigidBody.h:98
btVector3 m_totalForce
Definition: btRigidBody.h:70
btScalar m_inverseMass
Definition: btRigidBody.h:64
btVector3 computeGyroscopicImpulseImplicit_Body(btScalar step) const
perform implicit force computation in body space (inertial frame)
btVector3 m_totalTorque
Definition: btRigidBody.h:71
btScalar m_angularDamping
Definition: btRigidBody.h:74
void removeConstraintRef(btTypedConstraint *c)
void setMassProps(btScalar mass, const btVector3 &inertia)
btVector3 m_deltaAngularVelocity
Definition: btRigidBody.h:97
const btVector3 & getLinearVelocity() const
Definition: btRigidBody.h:433
btVector3 m_pushVelocity
Definition: btRigidBody.h:100
bool m_additionalDamping
Definition: btRigidBody.h:76
int m_debugBodyId
Definition: btRigidBody.h:93
btScalar m_angularSleepingThreshold
Definition: btRigidBody.h:83
void clearGravity()
const btCollisionShape * getCollisionShape() const
Definition: btRigidBody.h:242
btScalar m_additionalLinearDampingThresholdSqr
Definition: btRigidBody.h:78
btVector3 m_linearVelocity
Definition: btRigidBody.h:62
void setDamping(btScalar lin_damping, btScalar ang_damping)
btVector3 m_deltaLinearVelocity
Definition: btRigidBody.h:96
btVector3 m_angularVelocity
Definition: btRigidBody.h:63
void setupRigidBody(const btRigidBodyConstructionInfo &constructionInfo)
setupRigidBody is only used internally by the constructor
Definition: btRigidBody.cpp:40
void setCenterOfMassTransform(const btTransform &xform)
btAlignedObjectArray< btTypedConstraint * > m_constraintRefs
Definition: btRigidBody.h:89
void updateInertiaTensor()
void predictIntegratedTransform(btScalar step, btTransform &predictedTransform)
continuous collision detection needs prediction
btVector3 computeGyroscopicForceExplicit(btScalar maxGyroscopicForce) const
explicit version is best avoided, it gains energy
btVector3 m_invMass
Definition: btRigidBody.h:99
btVector3 m_gravity_acceleration
Definition: btRigidBody.h:68
virtual btChunk * allocate(size_t size, int numElements)=0
virtual void finalizeChunk(btChunk *chunk, const char *structType, int chunkCode, void *oldPtr)=0
static void integrateTransform(const btTransform &curTrans, const btVector3 &linvel, const btVector3 &angvel, btScalar timeStep, btTransform &predictedTransform)
static void calculateVelocity(const btTransform &transform0, const btTransform &transform1, btScalar timeStep, btVector3 &linVel, btVector3 &angVel)
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:30
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:108
btQuaternion getRotation() const
Return a quaternion representing the rotation.
Definition: btTransform.h:118
TypedConstraint is the baseclass for Bullet constraints and vehicles.
const btRigidBody & getRigidBodyA() const
const btRigidBody & getRigidBodyB() const
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:82
const btScalar & y() const
Return the y value.
Definition: btVector3.h:577
btScalar length() const
Return the length of the vector.
Definition: btVector3.h:257
const btScalar & z() const
Return the z value.
Definition: btVector3.h:579
btVector3 cross(const btVector3 &v) const
Return the cross product between this and another vector.
Definition: btVector3.h:380
void getSkewSymmetricMatrix(btVector3 *v0, btVector3 *v1, btVector3 *v2) const
Definition: btVector3.h:648
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition: btVector3.h:640
btVector3 normalized() const
Return a normalized version of this vector.
Definition: btVector3.h:949
const btScalar & x() const
Return the x value.
Definition: btVector3.h:575
btScalar length2() const
Return the length of the vector squared.
Definition: btVector3.h:251
void setZero()
Definition: btVector3.h:671
void serialize(struct btVector3Data &dataOut) const
Definition: btVector3.h:1317
The btRigidBodyConstructionInfo structure provides information to create a rigid body.
Definition: btRigidBody.h:110
btScalar m_friction
best simulation results when friction is non-zero
Definition: btRigidBody.h:124
btScalar m_restitution
best simulation results using zero restitution.
Definition: btRigidBody.h:131
btMotionState * m_motionState
When a motionState is provided, the rigid body will initialize its world transform from the motion st...
Definition: btRigidBody.h:115
btScalar m_rollingFriction
the m_rollingFriction prevents rounded shapes, such as spheres, cylinders and capsules from rolling f...
Definition: btRigidBody.h:127