Additional Parameters for Body Models

When using the AGX Dynamics plugin, the following additional parameters are available for body models.

Syntax

links:
  -
    name: Arm
    jointCompliance: 1e-8
    jointSpookDamping: 0.0333
    jointMotor: true
    jointMotorCompliance: 1e-8
    jointMotorSpookDamping: 0.0333
    jointMotorForceRange: [ -1000, 1000 ]
    jointRangeCompliance: 1e-8
    jointRangeSpookDamping: 0.0333
    jointRangeForceRange: [ -1000, 1000 ]
    jointLock: true
    jointLockCompliance: 1e-8
    jointLockSpookDamping: 0.0333
    jointLockForceRange: [ -1000, 1000 ]
    convexDecomposition: true
    AMOR: true
    autoSleep: true

collisionDetection:
  excludeTreeDepth: 3
  excludeLinks: [ ]
  excludeLinksDynamic: [ ]
  excludeLinkGroups:
    -
      name: groupA
      links: [ linkA, linkB, linkC, ... ]
    -
      name: groupB
      links: [ linkZ, linkY, linkX, ... ]
  excludeSelfCollisionLinks: [ linkP ]
  excludeLinksWireCollision: [ linkQ, linkR, ... ]

Parameter Descriptions

Link Parameters

Parameter	Default Value	Unit	Type	Description
jointCompliance	1e-8	m/N or rad/Nm	double	Joint compliance. Smaller values make joints more rigid, larger values make them more flexible.
jointSpookDamping	0.0333	s	double	Joint spook damping
jointMotor	false	-	bool	Enables joint motor. Automatically enabled when ActuationMode is JOINT_TORQUE or JOINT_VELOCITY.
jointMotorCompliance	1e-8	m/N or rad/Nm	double	Joint motor compliance. Used for velocity control. Smaller values produce higher output to reach target velocity. Larger values may fail to resist external forces (gravity, contact forces) and not reach target velocity.
jointMotorSpookDamping	0.0333	s	double	Joint motor spook damping
jointMotorForceRange	[ double_min, double_max ]	N or Nm	Vec2	Maximum and minimum force/torque limits for joint motor
jointRangeCompliance	1e-8	m/N or rad/Nm	double	Joint range limit compliance. Smaller values produce higher output to maintain joint limits. Larger values may allow exceeding limits due to external forces (gravity, contact forces).
jointRangeSpookDamping	0.0333	s	double	Joint range limit spook damping
jointRangeForceRange	[ double_min, double_max ]	N or Nm	Vec2	Maximum and minimum force/torque for joint range limits
jointLock	false	-	bool	Enables joint locking. Used for position control. Automatically enabled when ActuationMode is JOINT_ANGLE.
jointLockCompliance	1e-8	m/N or rad/Nm	double	Joint lock compliance. Smaller values produce higher output to reach target position. Larger values may fail to resist external forces (gravity, contact forces) and not reach target position.
jointLockSpookDamping	0.0333	s	double	Joint lock spook damping
jointLockForceRange	[ double_min, double_max ]	N or Nm	Vec2	Maximum and minimum force/torque for joint lock
convexDecomposition	false	-	bool	Enable/disable convex decomposition. Specify true or false.
AMOR	false	-	bool	Merges relatively stationary rigid bodies to reduce solver computational load. Specify true or false. Also requires setting the corresponding property in AGXSimulator Item.
autoSleep	false	-	bool	Enable/disable auto sleep. Specify true or false. Removes stationary rigid bodies from solver to reduce computational load. The AutoSleep property in AGXSimulator Item must also be set to true.

Collision Detection Settings

Parameter	Default Value	Unit	Type	Description
excludeLinksDynamic	-	-	string list	Disables collision detection for specified links. However, collisions with special objects like wires remain enabled.
excludeLinkGroups: - name links	-	-	string string list	Disables collisions between links registered in the group. Group name (optional) Link names
excludeSelfCollisionLinks	-	-	string list	Disables self-collision between specified links and the body
excludeLinksWireCollision	-	-	string list	Disables collision between specified links and AGXWire

The standard Choreonoid Collision Detection Setting parameters “excludeTreeDepth” and “excludeLinks” can also be specified.

Convex Decomposition

AGX Dynamics includes functionality to decompose triangular mesh shapes into convex shapes. When convexDecomposition is set to true for a link parameter, convex decomposition of triangular mesh shapes is performed. Convex decomposition can potentially improve collision detection performance.

Note

Convex decomposition may fail for complex shapes.

Note

Contact points may differ between triangular meshes and convex decomposed shapes, potentially resulting in different collision behavior.

Samples are available at:

• Project file: choreonoid/sample/AGXDynamics/agxConvexDecomposition.cnoid

• Body file: choreonoid/sample/AGXDynamics/vmark.body

When you run the sample, convex decomposition is executed and the shape is composed of multiple convex shapes.