Creating a Surface Extension

Working in Auto-Pilot Mode

You can create most surface extensions from minimum G2 and G1 lengths in auto-pilot mode. This mode is proposed by default when you enter Surface Extension.

From the Molded Part section of the action bar, click Surface Extension .
Select an axis system (Stamping Direction).
Select the surface to extend.
On the selected surface, select:
- Either wires (Boundaries or stable split curves) to extend on this surface.
  Notes:
  - If you select a stable split curve, the support surface and the up-to-element (in any) are automatically detected.
  - You can orient or drag the planes delimiting the 3D area to restrain it.
    You can add a tangency constraint to the planes, with respect to an inside edge.
    You can rotate the plane by editing the Robot.
- Or faces to extend on this surface.
- Or nothing. In this case, all border faces are extended.
Tip: For the best possible support of design change, select wires, especially stable split curves.
Optional: Select an up-to-element to trim the extended surface by this element (No need to compute distances).
- Without an up-to element
- With an up-to element
Select inner edges to guide the G1 extrapolation.

Note: If you are using a combination of G1 and G2 extrapolations, inner edges are retrieved on the G2 extrapolation.
Enter the Min. G2 Length and Min. G1 Length values.
Surface Extension tries to compute G2 extensions. If impossible, it creates G1 extensions, both from the values entered.

Working with Editable Parameters

You can display more parameters and edit them to compute extensions, if the auto-pilot mode failed to do so.

Select the Customize Extension check box.
Select the required check boxes.
- Work Face by Face
- Work With Untrims
- Check Tangency
- Check Undercuts and Overlaps.
Specify the other values as required.
- G2 length of the extended surface and G1 length of the extended surface define the portion of the extended surface with G2 or G1 continuity.
  Note: To apply a G1 length, specify G2 length of the extended surface to 0 and vice versa. You can also combine both options.
- Step back length is used to trim back the extended surface when its border is irregular.
  Note: Trimming also removes unwanted vertices.
- Smoothing deviation is used to clean the end border of the extended surface.
  Notes:
  - Trim back does not apply when an up-to element is selected, unless you have requested a combination of G2/G1: Extensions in G2 are cleaned to avoid useless vertices and profiles in G1 extensions.
  - Otherwise, each extension with a continuity request is cleaned.
- Deburring width is used when working face by face results in a multi-domains body. To solve this problem, a patch is applied locally to the body, where a lack of continuity is detected. The width of this patch is equal to twice the deburring width.
- Distance to patch clean border is used when working face by face. It is the distance between the surface and the clean surface border.
If extension fails, errors are displayed, with a visualization of the problem to help you solve errors.

A Surface extension feature (geometry) is created under the Clean Contour node. The Surface extension feature contains the input parameters. The Clean Contour node contains the planes that limit the extension, if any.

Note: Between several extended surfaces, G0, G1 nor G2 continuity cannot be guaranteed. You may need to go to Generative Shape Design to connect several extended surfaces.