Reverse the direction of a curve or surface

Reverse the tangent direction of a curve (by swapping the start and end points), or the parametric directions (U/V) of a surface.

Reverse, swap, or examine the directions (tangents) of a surface

1. If you want to reverse the direction of several surfaces at once, select them now.
2. Choose Surface Edit > Reverse Surface UV .
3. In the option box, choose whether you want to reverse the U direction, the V direction, or swap U and V.
4. Click on the first surface you want to examine or reverse.

   An indicator appears on the surface showing the current tangent(s) (U, V, or both, depending on the option chosen).

5. Do any of the following:
   • Click the and drag over the surface to examine the tangent direction(s).
   • Click the or the Reverse Active button in the window to reverse the surface you clicked.
   • Click the or the Reverse All button in the window to reverse all selected surfaces.
6. Click on another surface and repeat step 5.
   Note:

   Reversing the direction of the U and V parameters on a surface affects the surface normal, but does not affect the surface orientation. See Normals and surface orientation for details.

Reverse the direction of a curve

1. Choose Curve Edit > Reverse Curve.
2. Click the first curve you want to reverse.

   The tangent of the curve is shown at the point where you clicked.

3. Do any of the following:
   • Click the and drag along the curve to examine the tangent direction.
   • Click the or the Reverse Active button in the window to reverse the curve you clicked.
   • Click the or the Reverse All button in the window to reverse all selected curves.
4. Click on another curve to add to the selection and repeat step 3.
   Note:

   You can also select all the curves you want to reverse before entering the tool.