diff options
Diffstat (limited to 'extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h')
-rw-r--r-- | extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h index 84ea9e04095..8a893d4fb8c 100644 --- a/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h +++ b/extern/bullet2/src/BulletDynamics/ConstraintSolver/btConeTwistConstraint.h @@ -17,6 +17,22 @@ Written by: Marcus Hennix +/* +Overview: + +btConeTwistConstraint can be used to simulate ragdoll joints (upper arm, leg etc). +It is a fixed translation, 3 degree-of-freedom (DOF) rotational "joint". +It divides the 3 rotational DOFs into swing (movement within a cone) and twist. +Swing is divided into swing1 and swing2 which can have different limits, giving an elliptical shape. +(Note: the cone's base isn't flat, so this ellipse is "embedded" on the surface of a sphere.) + +In the contraint's frame of reference: +twist is along the x-axis, +and swing 1 and 2 are along the z and y axes respectively. +*/ + + + #ifndef CONETWISTCONSTRAINT_H #define CONETWISTCONSTRAINT_H @@ -141,7 +157,18 @@ public: }; } - void setLimit(btScalar _swingSpan1,btScalar _swingSpan2,btScalar _twistSpan, btScalar _softness = 1.f, btScalar _biasFactor = 0.3f, btScalar _relaxationFactor = 1.0f) + // setLimit(), a few notes: + // _softness: + // 0->1, recommend ~0.8->1. + // describes % of limits where movement is free. + // beyond this softness %, the limit is gradually enforced until the "hard" (1.0) limit is reached. + // _biasFactor: + // 0->1?, recommend 0.3 +/-0.3 or so. + // strength with which constraint resists zeroth order (angular, not angular velocity) limit violation. + // __relaxationFactor: + // 0->1, recommend to stay near 1. + // the lower the value, the less the constraint will fight velocities which violate the angular limits. + void setLimit(btScalar _swingSpan1,btScalar _swingSpan2,btScalar _twistSpan, btScalar _softness = 1.f, btScalar _biasFactor = 0.3f, btScalar _relaxationFactor = 1.0f) { m_swingSpan1 = _swingSpan1; m_swingSpan2 = _swingSpan2; |