Approximating and Segmenting Procedural Surfaces

You can convert surfaces into a NUPBS (Non-Uniform Polynomial B-Spline) surface, and modify the number of patches (segments).

Note: This approximation automatically performs when you edit a surface using control points.

Before you begin: Open an existing 3D shape.
See Also
Approximating and Segmenting Procedural Curves
  1. Select the surface.

    Notes:
    • You can multiselect surfaces.
    • To convert a multi-cell curve, select it from the tree to ensure that you select the whole curve instead of one cell only.
    • You can mix the approximation of curves and surfaces.
    • Use the Exact conversion mode on a NUPBS element to display the number of control points, the curve order, and the number of curve segments. In this case, the initial element duplicates.

  2. From the Edition section of the action bar, click Converter Wizard .
    Depending on the type of the initial element, a text appears indicating what approximation you can perform:
    • CV: The element is not a NUPBS and needs to be approximated using the Converter Wizard parameters.
    • EXACT: The element can be converted in Exact mode.
    • Seg: The element already is a NUPBS.
  3. Optional: Specify the deviation Tolerance from the initial surface.
  4. Optional: Specify the maximum allowed Orders along the U and V directions for each surface patch. This value must be greater than or equal to 2, in a given direction, when the segmentation options are grayed. Otherwise, it must be greater than or equal to 4 when the maximum allowed number of segments along the U or V is greater than or equal to 2.

    The maximum value allowed per patch is defined in the Order option in Me > Preferences > App Preferences > 3D Modeling > Styling > FreeStyle Shape Design, General tab, Geometry section, and must be less than or equal to 16.

  5. Optional: Set the Segmentation, that is the maximum allowed segments along the U and V directions. If Single is selected, a mono-segment surface is created.
  6. Click Priority for Order or Segmentation to define which parameter takes precedence over the other one.
  7. Optional: Click Continuity in the App Options panel.
    If at least one conversion option is active (Tolerance, Orders, or Segmentation, that is, you are not in exact conversion mode), a continuity constraint can be imposed identically on the selected surfaces.
  8. Optional: Click More to display additional options.
  9. Optional: Select Information to display further information on the element.
    • Max: Maximum deviation in relation to the initial element.
    • N: Number of control points in U and V.
    • o: Surface order.
    • s: Number of segments in the surface.
  10. Optional: Select Control Points to display the surface's control points.
  11. Optional: Select Auto Apply to dynamically update the resulting surface.
  12. Click OK.