Using the Invert Surface command you can very easily and interactively reverse the direction of a surface normal. After starting the command, proceed as follows.
1 | Select the surface to be modified. Remember you can always change the selected surface (for example if you selected the wrong one by mistake) by clicking on Surfaces and selecting a new surface (or by right-clicking on Surfaces, choosing Reset in the context menu and selecting a new surface). If the selected surface is not a NURBS, you will be asked to confirm whether you want to convert it into a NURBS (unless you have deselected the Ask before converting check box). |
2 | An arrow is displayed to show the current surface normal. Move the cursor onto the arrow and double-click to invert the orientation. The change will be immediately displayed. |
3 | Click or to confirm your selections and create the surface. Click to discard your changes. |