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]