tangentConstraint

Tangent Constraint Attributes

Lock Output: Specifies whether or not you can directly manipulate an object’s constrained channels. For example, when the tangent constraint’s Lock Output attribute is off, you can change the orientation of the constrained object to an orientation different from that of the driver curve.

When a constrained object’s Lock Output attribute is on, you can only manipulate its constrained channels by transforming its driver object. When a constrained object’s Lock Output attribute is off, you can directly manipulate its constrained channels, without having to transform its driver object.

NoteThe Animation Blending preferences affect the default state of the Lock Output attribute.
Aim Vector: Specifies the direction of the aim vector relative to the constrained object’s local space. The aim vector aligns with the target vector, forcing the constrained object to orient itself accordingly. The default specifies that the object’s local rotation positive X-axis aligns with the aim vector, which aligns with the target vector (1.0000, 0.0000, 0.0000).
Up Vector: Specifies the direction of the up vector relative to the constrained object’s local space. The default specifies that the object’s local rotation positive Y-axis aligns with the up vector. In turn, by default, the up vector tries to align with the world up vector. Further, by default, the world up vector points in the direction of the world space’s positive Y-axis (0.0000, 1.0000, 0.0000).

If you define the up vector to point in the same direction as the aim vector, the constrained object will be motion history dependent. For more information, see Motion history dependence effects.
World Up Vector: Specifies the direction of the world up vector relative to the scene’s world space. Because Maya’s world space is “Y-up” by default, the default world up vector points in the direction of the world space’s positive Y-axis (0.0000, 1.0000, 0.0000).

World Up Type

Specifies the role of the world up vector. Selections include Scene Up, Object Up, Object Rotation Up, Vector, and None.

Scene Up: Specifies that the up vector try to align with the scene’s up axis instead of the world up vector. The world up vector is ignored.

(To specify the scene’s up axis, select Window > Settings/Preferences > Preferences. In the Settings category of the Preferences window, select Y or Z for the Up Axis of the World Coordinate System. Y is the default.)
Object Up: Specifies that the up vector try to aim at the origin of a specified object instead of aligning with the world up vector. The world up vector is ignored. The object whose origin the up vector tries to aim at is called the world up object. You can specify the world up object with the aimConstraint MEL command (use -wuo flag). If no world up object is specified, the up vector tries to aim at the origin of the scene’s world space.
Object Rotation Up: Specifies that the world up vector is defined relative to some object’s local space instead of the scene’s world space. The up vector tries to align with the world up vector after transforming it relative to the scene’s world space. The object whose origin the up vector tries to aim at is called the world up object. You can specify the world up object with the aimConstraint MEL command (use -wuo flag). If no world up object is specified, the world up vector is defined relative to the scene’s world space.
Vector: Specifies that the up vector tries to align with world up vector as closely as possible. The world up vector is defined relative to the scene’s world space. (This is the default.)
None: Specifies no calculation of the constrained object’s orientation about the aim vector. The orientation continues as whatever the orientation is right before you specify None. With None selected, the constrained object becomes motion history dependent. For more information, see Motion history dependence effects.

World Up Object: Specifies that the up vector try to aim at the origin of a specified object instead of aligning with the world up vector. The world up vector is ignored. The object whose origin the up vector tries to aim at is called the world up object. You can specify the world up object with the aimConstraint MEL command (use -wuo flag). If no world up object is specified, the up vector tries to aim at the origin of the scene's world space.
Constraint Rotate: Informs you of the current orientation of the constrained object.
Constraint Vector: Informs you of the current target vector, which is what the aim vector aligns with.
Enable Rest Position: See Rest Position attributes.
Rest Rotate: See Rest Position attributes.