Trajectory Constraint Property Editor

Constrains an object so that it follows the points on a curve during playback.

For more information, see Setting Objects on Trajectories [Animation].

To apply: Select an object, Constrain Trajectory, then pick the curve to which the selected object will be constrained.

To redisplay: Select the constrained object, choose Explore Constraints on the MCP, and click the constraint's icon.

Active	Toggles the activeness of this constraint.
Blend Weight	Blends the weight of this constraint with other constraints on the selected object.
Start Frame	Sets the frame number where the constraint begins during playback. If you set this value to 10, for example, the constrained object will only follow the trajectory of a path once the animation reaches the tenth frame in the sequence.

Attach Point -- Constrained Object

Affected by Orientation	Constrained object is affected by the orientation of the constraining object.
Affected by Scaling	Constrained object is affected by the scale of the constraining object.
X/Y/Z	Sets the offset distance in global space on the X/Y/Z axes of the constrained object in relation to the constraining object. If you add an offset, you can set the Coupling to either soft or rigid.
Coupling	Determines how constrained object move in relation to the constraining object when there is an offset between them (set with the X/Y/Z sliders). When the offsets for both the constrained and constraining objects are set to zero (off), the coupling has no effect. Rigid: The constrained object mimics the rotation of the constraining object. Rigid constraints are represented by a small square in the center of the constraining object. Soft: The constrained object is allowed a certain degree of flexibility in relation to the constraining object, similar in nature to a ball joint. Soft constraints are represented by a small circle in the centers of the constrained and constraining objects.

Tangency

Tangency Active

Toggles the activeness of the tangency values set for this constraint.

Axis to Align

X/Y/Z

When Tangency is active, sets the axis of the constrained object that will always face the slope of the constraining curve.

Up Vector

The up-vector constraint makes the Y axis of a constrained object point to a constraining (control) object or a specific point. See Up Vector Options for information.