jit.phys.conetwist Reference

A conetwist constraint in a physics world

jit.phys.conetwist

Description

jit.phys.conetwist is a special point-to-point constraint that restricts the translation and allows limits on the rotation. The x-axis serves as a twist axis. This can be useful to represent limbs of a body, such as arms and legs. Motor forces can be applied to the constraint. If only a single body is bound, it is constrained to a point in world space.

Examples

A conetwist constraint in a physics world

Attributes

bias [float]

Magnitude of the limit's position correction (default = 0.3). This attribute sets how strictly the position error is corrected. For most cases, the value should not be greater than 1.

body1 [symbol]

The name of the first jit.phys.body to constrain.

body2 [symbol]

The name of the second jit.phys.body to constrain.

collisions [int]

Enables collisions between attached bodies (default = 0).

enable [int]

Enable this constraint in the physics simulation (default = 1).

position1 [3 floats]

The pivot point of body1 as a 3D vector relative to the body1 center of mass (default = 0 0 0).

position2 [3 floats]

The pivot point of body2 as a 3D vector relative to the body2 center of mass (default = 0 0 0). If body2 is blank, this is the worldspace position of the constraint.

quat1 [4 floats]

The quaternion orientation of body1 relative to the constraint (default = 0 0 0 1).

quat2 [4 floats]

The quaternion orientation of body2 relative to the constraint (default = 0 0 0 1). If body2 is blank, this is the worldspace orientation of the constraint.

relaxation [float]

The rate at which velocity errors are corrected by limits, effectively the strength of the limits (default = 1.0) . Lower values specify weaker limits. For most cases, the relaxation value should not be greater than 1.

rotate1 [4 floats]

Rotation of body1 relative to the constraint (default = 0 0 0 1).

rotate2 [4 floats]

Rotation of body2 relative to the constraint (default = 0 0 0 1). If body2 is blank, this is the worldspace orientation of the constraint.

rotatexyz1 [3 floats]

Euler rotation of body1 relative to the constraint (default = 0 0 0).

rotatexyz2 [3 floats]

Euler rotation of body2 relative to the constraint (default = 0 0 0). If body2 is blank, this is the worldspace orientation of the constraint.

strength [float]

Set the constraint strength (default = 0.2). Determines what proportion of the joint error will be fixed each simulation step. Values between 0.1 and 0.8 are recommended.

stretch [float]

Set the constraint stretch (default = 0.0). Setting to a positive value allows forces acting on rigid bodies to violate the constraint by an amount proportional to the stretch value.

swing1limit [float]

The limit of allowed rotation in degrees in either direction around the swing 1 axis (default = 180). With a limit of 180 degrees, rotation is unconstrainted around the axis.

swing2limit [float]

The limit of allowed rotation in degrees in either direction around the swing 2 axis (default = 180). With a limit of 180 degrees, rotation is unconstrainted around the axis.

twistlimit [float]

The limit, in degrees, of allowed rotation in degrees in either direction around the twist axis (default = 180). With a limit of 180 degrees, rotation is unconstrainted around the axis.

worldname [symbol]

The name of a jit.phys.world context this constraint is bound to.

worldpos [3 floats]

g/s(get)

The derived constraint world position (default = 0 0 0)

worldquat [4 floats]

g/s(get)

The derived constraint world quaternion (default = 0 0 0 1)

Common Box Attributes

Messages

reset

Removes any current forces and returns the attached objects to their original position.

See Also

Name Description
Working with OpenGL Working with OpenGL
jit.phys.world
jit.phys.body
jit.phys.barslide
jit.phys.hinge
jit.phys.point2point
jit.phys.6dof