How do I use the tangent direction manipulator?

• To set the tangent direction, click an axis line.

  For direction constraints, the axis lines relate to world space (X, Y, Z). For geometry constraints, the axis lines relate to the curve, surface, or point cloud (U, V, Normal).

• To change the rotation freely, click the rotation handle (the small circle on the arrow), then drag with the different mouse buttons or type rotational coordinates.

  

• To change the rotation in a plane, click an arc, then drag left and right or type a rotation angle.
• To change the tangent magnitude, click the square, then drag left or right or type a value.

  

• To change the curvature magnitude, click the large circle, then drag left or right or type a value. The default is 1.0.

  

  This handle appears when the constraint’s continuity is set to G2 or higher.

• To change the curvature rate of change, click the small circle, then drag left or right or type a value. The default is 1.0.

  

  This handle appears when the constraint’s continuity is set to G3 or higher.