pymel.core.effects.constrain

constrain(*args, **kwargs)

This command constrains rigid bodies to the world or other rigid bodies. In query mode, return type is based on queried flag.

Flags:

Long name (short name)		Argument Types	Properties
barrier (br)		bool
	Creates a barrier constraint. This command requires one rigid bodies.
damping (d)		float
	Sets the damping constant. Default value: 0.1 Range: -1000.0 to 1000.0
directionalHinge (dhi)		bool
	Creates a directional hinge constraint. This command requires two rigid bodies. The directional hinge always maintains the initial direction of its axis.
hinge (hi)		bool
	Creates a hinge constraint. This command requires one or two rigid bodies.
interpenetrate (i)		bool
	Allows (or disallows) the rigid bodies defined in the constrain to ipenetrate.Flag can appear in Create mode of commandFlag can have multiple arguments, passed either as a tuple or a list.
nail (na)		bool
	Creates a nail constraint. This command requires one rigid body.
name (n)		unicode
	Names the rigid constraint.
orientation (o)		float, float, float
	Set initial orientation of the constraint in world space. This command is only valid with hinge and barrier constraints Default value: 0.0 0.0 0.0
pinConstraint (pin)		bool
	Creates a pin constraint. This command requires two rigid bodies.
position (p)		float, float, float
	Set initial position of the constraint in world space. Default value: 0.0 0.0 0.0 for uni-constraints, midpoint of bodies for deul constraint.
restLength (rl)		float
	Sets the rest length. Default value: 1.0
spring (s)		bool
	Creates a spring constraint. This command requires one or two rigidies.
stiffness (st)		float
	Sets the springs stiffness constant. Default value: 5.0

Derived from mel command maya.cmds.constrain

Example:

import pymel.core as pm

# "Nail" a rigid body at position ""0.0, 2.5, 0.0""
#
pm.constrain( 'rigidBody1', nail=True, p=(0, 2.5, 0) )

# "Pin" two rigid bodies together at the position ""0.0, 2.5, 0.0"".
#
pm.constrain( 'rigidBody1', 'rigidBody2', pin=True, n='pin', p=(0, 2.5, 0) )

# "Hinge" a rigid body at the position ""0.0, 2.5, 0.0"".
#
pm.constrain( 'rigidBody1', hinge=True, p=(0, 2.5, 0) )

# Create a barrier for a rigid body which will not allow the rigid body
# to fall below (in y by default) the plane defined by the
# barrier point ""0.0, 2.5, 0.0"".
#
pm.constrain( 'rigidBody1', barrier=True, p=(0, 2.5, 0) )

# Add a "Spring" to a rigid body at the position ""0.0, 2.5, 0.0""
# connected on the rigid body at point ""0, 0, 0""
#
pm.constrain( 'rigidBody1', spring=True, name='spring', p=(0, 2.5, 0), rl=1.0 )