jit.phys.hinge Reference

A hinge constraint in a physics world

jit.phys.hinge

Description

The jit.phys.hinge object restricts two additional angular degrees of freedom so an attached jit.phys.body object can only rotate around the hinge axis. This can be useful to represent doors or wheels rotating around one axis. Limits and Motor forces can be specified for the hinge. If only a single body is bound, it is constrained to a point in world space.

Examples

A hinge 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).

hingeangle [float]

g/s(get)

The angle, in degrees, between constrained bodies around the hinge axis (default = 0).

lowerlimit [float]

The lower limit, in degrees, of allowed rotation around the hinge axis (default = 1). If lowerlimit is greater than upper limit, no limits are applied to the constraint.

motorstrength [float]

The maximum motor impulse (default 1.).

motortarget [float]

Angle around hinge axis, in degrees, the motor is targeting (default = 0).

motorvelocity [float]

Enables motor and specifies velocity desired in degrees per second (default = 0).

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 hinge constraint (default = 0 0 0 1). Default value sets hinge axis to z axis.

quat2 [4 floats]

The quaternion orientation of body2 relative to the hinge constraint (default = 0 0 0 1). Default value sets hinge axis to z axis. 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). Default value sets hinge axis to z axis.

rotate2 [4 floats]

Rotation of body2 relative to the constraint (default = 0 0 0 1). Default value sets hinge axis to z axis. 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). Default value sets hinge axis to z axis.

rotatexyz2 [3 floats]

Euler rotation of body2 relative to the constraint (default = 0 0 0). Default value sets hinge axis to z axis. 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.

upperlimit [float]

The upper limit, in degrees, of allowed rotation around the hinge axis (default = -1). If lowerlimit is greater than upper limit, no limits are applied to the constraint.

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.conetwist
jit.phys.point2point
jit.phys.6dof