Creating a Net Surface  

This task shows you how to create a subdivision surface, based on an existing set of curves (the net).

Create a shape containing several curves. They can be any kind of curves: IMA curves, 3D curves, border of a face, and so on.
You can also open the NetSurface.CATPart document.
 

  1. Click Net Surface in the Creation toolbar.
    You can also access this command by pressing ALT+SHIFT+N.

    A Tools Palette is displayed:

    Option Description  Shortcuts
    Guides Selection Select the guides (selected by default). Ctrl + Shift + U
    Profiles Selection Select the profiles. Ctrl + Shift + V
    Net Feature Creates the surface with links to the input curves. Ctrl + Shift + Z
    Subdivision Feature Create the surface without any link to the input curves. Ctrl + Shift + Z
    Apply Applies the command.  

  2. Click Guides Selection .
    By default, it is selected.

  3. Select the guide curves (horizontal curves).
    The net surface is dynamically previewed:

  4. Click Profiles Selection .

  5. Select the profile curves (vertical curves).
    The net surface is dynamically modified:

      The value shown in the 3D area corresponds to the maximum deviation between the generated surface and the selected profile and guide curves and is displayed at the point where this deviation has been computed. 

    New icons appear in the Tools Palette:

     
    Option Description  Shortcuts
    Swap Curves Swap guide curves with profile curves and vice-versa. Ctrl + Shift + I
    Best Solution Gives the best solution in both guide and profile directions. This command is available only when Subdivision Feature is selected. Ctrl + Shift + B
    Face Number for Guide Defines the number of faces for each guide using a slider. Ctrl + Shift + W
    Face Number for Profile Defines the number of faces for each profile using a slider. Ctrl + Shift + Y

  6. Click Swap Curves .

  7. Click Best Solution .
    The best solution in both guide and profile directions is displayed:

    This capability may generate important number of faces or profiles. To decrease or increase them, use the Face Number for Guide and the Face Number for Profile commands.

  8. Click Face Number for Guide .

    The Value Edition icon appears in the Tools Palette and a slider is displayed at the right of the screen to let you define the number of faces in the guide direction. The maximum number of faces is defined by default.

    You can also drag the slider to increase or decrease the  number of faces.

    The minimum number of faces in the guide direction corresponds to the number of profile curves - 1.

  9. Click Face Number for Profile .

    The Value Edition icon appears in the Tools Palette and a slider is displayed at the top of the screen to let you define the number of faces in the profile direction. The maximum number of faces is defined by default.

    You can also drag the slider to increase or decrease the  number of faces.

    The minimum number of faces in the profile direction corresponds to the number of guide curves - 1.

  10. Click Apply to validate the command.
    The subdivision surface is created.
    In the specification tree, the created surface appears as     Subdivision Net.x if Net Feature is activated. If Subdivision Feature is activated, it appears as Subdivision Surface.x.

  11. Double-click the surface to modify and deform the created surface.
    The Tools Palette appears.

  • Profile curves must not intersect each other.
  • Guide curves must not intersect each other.
  • Sometimes the maximum number of given faces may not be reached.
  • The created shape may not exactly follow the guide and profile curves.
  • If you have selected the border of a surface as the curve input, the resulting subdivision surface will not be continuous in point with the neighboring surfaces.