joint

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Synopsis

joint [-absolute] [-angleX angle] [-angleY angle] [-angleZ angle] [-assumePreferredAngles] [-automaticLimits] [-children] [-component] [-degreeOfFreedom string] [-exists string] [-limitSwitchX boolean] [-limitSwitchY boolean] [-limitSwitchZ boolean] [-limitX angle angle] [-limitY angle angle] [-limitZ angle angle] [-name string] [-orientJoint string] [-orientation angle angle angle] [-position linear linear linear] [-radius float] [-relative] [-rotationOrder string] [-scale float float float] [-scaleCompensate boolean] [-scaleOrientation angle angle angle] [-secondaryAxisOrient string] [-setPreferredAngles] [-stiffnessX float] [-stiffnessY float] [-stiffnessZ float] [-symmetry boolean] [-symmetryAxis string] [-zeroScaleOrient] [objects]

joint is undoable, queryable, and editable.

Multiple objects are allowed only for the edit mode. The same edit flags will be applied on all the joints selected, except for -p without -r (set joint position in the world space). An ik handle in the object list is equivalent to the list of joints the ik handle commands. When -ch/children is present, all the child joints of the specified joints, including the joints implied by possible ik handles, will also be included.

In the creation mode, a new joint will be created as a child of a selected transform or starts a hierarchy by itself if no transform is selected. An ik handle will be treated as a transform in the creation mode.

The default values of the arguments are:

-degreeOfFreedom xyz

-name "Joint#"

-position 0 0 0

-absolute

-dof "xyz"

-scale 1.0 1.0 1.0

-scaleCompensate true

-orientation 0.0 0.0 0.0

-scaleOrientation 0.0 0.0 0.0

-limitX -360 360

-limitY -360 360

-limitZ -360 360

-angleX 0.0

-angleY 0.0

-angleZ 0.0

-stiffnessX 0.0

-stiffnessY 0.0

-stiffnessZ 0.0

-limitSwitchX no

-limitSwitchY no

-limitSwitchZ no

-rotationOrder xyz

Those arguments can be specified in the creation mode, editied in the edit mode (-e), or queried in the query mode (-q).

Return value

In query mode, return type is based on queried flag.

Related

Flags

Long name (short name)	Argument types	Properties
-position(-p)	linear linear linear
Specifies the position of the center of the joint. This position may be relative to the joint's parent or in absolute world coordinates (see -r and -a below). When queried, this flag returns 3 floats.
-relative(-r)
The joint center position is relative to the joint's parent.
-absolute(-a)
The joint center position is in absolute world coordinates. (This is the default.)
-component(-co)
Use with the -position switch to position the joint relative to its parent (like -relative) but to compute new positions for all children joints so their world coordinate positions do not change.
-name(-n)	string
Specifies the name of the joint. When queried, this flag returns a string.
-degreeOfFreedom(-dof)	string
Specifies the degrees of freedom for the IK. Valid strings consist of non-duplicate letters from x, y, and z. The letters in the string indicate what rotations are to be used by IK. The order a letter appear in the string does not matter. Examples are x, yz, xyz. When queried, this flag returns a string. Modifying dof will change the locking state of the corresponding rotation attributes. The rule is: if an rotation is turned into a dof, it will be unlocked if it is currently locked. When it is turned into a non-dof, it will be locked if it is not currently locked.
-orientation(-o)	angle angle angle
The joint orientation. When queried, this flag returns 3 floats.
-rotationOrder(-roo)	string
The rotation order of the joint. The argument can be one of the following strings: xyz, yzx, zxy, zyx, yxz, xzy.
-scaleOrientation(-so)	angle angle angle
Set the orientation of the coordinate axes for scaling. When queried, this flag returns 3 floats.
-scale(-s)	float float float
Scale of the joint. When queried, this flag returns 3 floats.
-scaleCompensate(-sc)	boolean
It sets the scaleCompenstate attribute of the joint to the given argument. When this is true, the scale of the parent joint will be compensated before any rotation of this joint is applied, so that the bone to the joint is scaled but not the bones to its child joints. When queried, this flag returns an boolean.
-limitX(-lx)	angle angle
Set lower and upper limits on the x-axis of rotation. Also turns on the joint limit. When queried, this flag returns 2 floats.
-limitY(-ly)	angle angle
Set lower and upper limits on the y-axis of rotation. Also turns on the joint limit. When queried, this flag returns 2 floats.
-limitZ(-lz)	angle angle
Set lower and upper limits on the z-axis of rotation. Also turns on the joint limit. When queried, this flag returns 2 floats.
-angleX(-ax)	angle
Set the x-axis angle. When queried, this flag returns a float.
-angleY(-ay)	angle
Set the y-axis angle. When queried, this flag returns a float.
-angleZ(-az)	angle
Set the z-axis angle. When queried, this flag returns a float.
-stiffnessX(-stx)	float
Set the stiffness (from 0 to 100.0) for x-axis. When queried, this flag returns a float.
-stiffnessY(-sty)	float
Set the stiffness (from 0 to 100.0) for y-axis. When queried, this flag returns a float.
-stiffnessZ(-stz)	float
Set the stiffness (from 0 to 100.0) for z-axis. When queried, this flag returns a float.
-limitSwitchX(-lsx)	boolean
Use the limit the x-axis rotation? When queried, this flag returns a boolean.
-limitSwitchY(-lsy)	boolean
Use the limit the y-axis rotation? When queried, this flag returns a boolean.
-limitSwitchZ(-lsz)	boolean
Use the Limit the z-axis rotation? When queried, this flag returns a boolean.
-exists(-ex)	string
Does the named joint exist? When queried, this flag returns a boolean.
-automaticLimits(-al)
Meaningful only in edit mode. It sets the joint to appropriate hinge joint with joint limits. It modifies the joint only if (a) it connects exactly to two joints (one parent, one child), (b) it does not lie on the line drawn between the two connected joints, and the plane it forms with the two connected joints is perpendicular to one of its rotation axes.
-setPreferredAngles(-spa)
Meaningful only in the edit mode. It sets the preferred angles to the current joint angles.
-assumePreferredAngles(-apa)
Meaningful only in the edit mode. It sets the joint angles to the corresponding preferred angles.
-children(-ch)
It tells the command to apply all the edit options not only to the selected joints, but also to their descendent joints in the DAG.
-radius(-rad)	float
Specifies the joint radius.
-orientJoint(-oj)	string
The argument can be one of the following strings: xyz, yzx, zxy, zyx, yxz, xzy, none. It modifies the joint orientation and scale orientation so that the axis indicated by the first letter in the argument will be aligned with the vector from this joint to its first child joint. For example, if the argument is "xyz", the x-axis will point towards the child joint. The alignment of the remaining two joint orient axes are dependent on whether or not the -sao/-secondaryAxisOrient flag is used. If the -sao flag is used, see the documentation for that flag for how the remaining axes are aligned. In the absence of a user specification for the secondary axis orientation, the rotation axis indicated by the last letter in the argument will be aligned with the vector perpendicular to first axis and the vector from this joint to its parent joint. The remaining axis is aligned according the right hand rule. If the argument is "none", the joint orientation will be set to zero and its effect to the hierarchy below will be offset by modifying the scale orientation. The flag will be ignored if: A. the joint has non-zero rotations when the argument is not "none". B. the joint does not have child joint, or the distance to the child joint is zero when the argument is not "none". C. either flag -o or -so is set.
-secondaryAxisOrient(-sao)	string
The argument can be one of the following strings: xup, xdown, yup, ydown, zup, zdown, none. This flag is used in conjunction with the -oj/orientJoint flag. It specifies the scene axis that the second axis should align with. For example, a flag combination of "-oj yzx -sao yup" would result in the y-axis pointing down the bone, the z-axis oriented with the scene's positive y-axis, and the x-axis oriented according to the right hand rule.
-zeroScaleOrient(-zso)
It sets the scale orientation to zero and compensate the change by modifing the translation and joint orientation for joint or rotation for general transform of all its child transformations. The flag will be ignored if the flag -so is set.
-symmetry(-sym)	boolean
Create a symmetric joint from the current joint.
-symmetryAxis(-sa)	string
This flag specifies the axis used to mirror symmetric joints. Any combination of x, y, z can be used. This option is only used when the symmetry flag is set to True.

Flag can appear in Create mode of command	Flag can appear in Edit mode of command
Flag can appear in Query mode of command	Flag can be used more than once in a command.

MEL examples

// create a 3-joint chain
//
select -d;
joint -p 0 0 0 ;
joint -p 0 4 0 ;
joint -e -zso -oj xyz joint1;
joint -p 0 8 -1 ;
joint -e -zso -oj xyz joint2;
// Will create a 4th joint with z joint limits of -90 deg for
// the lower limit and 90 deg for the upper limit.  The
// joint will be positioned at (0, 0, 4) in world
// coordinates.
//
joint -lz -90deg 90deg -p 0 8 4;
// Set the joint limits but leave them disabled.
//
joint -edit -lz -90deg 90deg -lsz off;