Restoring a Trimmed Surface    

This task shows you how to restore the limits of a surface or a curve when it has been split using:
  • Break Surface or Curve (FreeStyle workbench)
  • Split (Generative Shape Design and Wireframe & Surface workbenches).

Open the FreeStyle_06.CATPart document.

  1. Click Untrim Surface or Curve .
 

The Untrim dialog box appears.
 


The Untrim dialog box has the following options:

Selection: When you select the elements to be untrimmed, the selected elements will be shown in the multi-selection field. The selections allowed are surface, curve and edges of surface.

Create Curves: You can extract the boundary of the selected elements using this option.

  • If “Create Curves” push button is ON, all the boundary edges of selected elements will be extracted as datum curves.

  • If “Create Curves” push button is OFF, datum curves will not be created.

  • All the datum curves will be added in the specification tree as Curve.XXX.

Create Extract: GSD Extract command is available by contextual menu on multi-selection field in untrim dialog box. You can create GSD Extract of the selected edges. The result of GSD extract will be added in multi-selection field and will be input for the untrim feature. The GSD Extract feature will be aggregated under untrim feature in specification tree. Result of extract feature will be used to identify whether you are willing to perform the untrim of entire outer loop or the partial outer loop. If the result of the extract feature is:

  • Face: then Untrim will be performed on entire face.

  • Part of inner loop: Untrim will be performed on the entire inner loop.

  • Entire Inner loop: Untrim will be performed on the entire inner loop.

  • Part of outer loop: Untrim will be performed on the part of the outer loop if possible otherwise entire outer loop will be used for untrim operation.

  • Entire outer loop: Untrim will be performed on the entire outer loop.

  • Multi domain boundary (Boundary of faces containing holes): Untrim will be performed based on the corresponding type of selection. (For example, If actual input of extract has multiple inner loops and one outer loop and the result of extract contained only one of the  inner loop and the outer loop then the untrim will be performed like local untrim of selected inner loop + local untrim of outer loop).

  • The Dashboard options that you can use are as follows:

    • Create Datum : This option is to create a datum feature.

  • While creating new Untrim feature:

    • You can either directly select the surface to be untrimmed.

    • Or you can select the edges of the surface interactively.

    • If you select an edge of the surface which is part of the inner loop the untrim will be performed on the entire inner loop.

    • If you select an edge of the surface which is part of the outer loop the untrim will be performed on the part of the outer loop only if it is possible to do so. Otherwise untrim will be performed on the entire outer loop.

    • The contextually created GSD Extract feature will not be directly used as input of Untrim feature.
      The input of GSD extract feature will be used as the input of untrim feature.
      For example if input of extract feature is a multi-cell surface then the input of untrim feature will also be the same multi-cell surface. It is not possible to use contextual GSD Extract command in the Untrim panel to extract a solid face or a face of multi-cell surface. In this case Extract the face before entering in the Untrim command.

  • In case of editing the existing untrim feature:

    • You will not be allowed to select multiple elements.

    • In case of multiple selections only last selection will be considered for the creation of the untrim.

    • When the selection is changed then all earlier extract features (aggregated under untrim) will be removed and then you have to manage creation of new extract if required.

    • Also please note that in case of edit mode if you create multiple extract features only the last created extract feature will be kept and the other features will be removed.

  • In case of editing the existing extract feature under untrim feature:

    • When the selection is changed then all earlier extract features (aggregated under untrim) will be removed from untrim feature and will be added in specification tree above untrim feature. Then, you have to manage creation of new extract if required.

The local undo/redo support for the selection is provided when you are working with untrim command.

You can decide to create the curves for the selection he has done to create untrim by enabling the option Create Curves on the dialog. In this case the datum curves will be created for the selection done by you except for extract feature. When entire face is selected as input, all the edges of the face will be extracted.

  1. Select the surface which limits should be restored.
 

The Untrim dialog box is updated accordingly.
 

  1. Click OK in the dialog box.
 

A progression bar is displayed, while the surface is restored.
It automatically disappears once the operation is complete (progression at 100%).
 

The initial surface is automatically restored.
If the surface is extrapolated by other operations such as trim or split, before using the Untrim Surface or Curve , it cannot be restored to its original shape.

 
 

The restored surface or curve is identified as Surface Untrim.xxx or Curve Untrim.xxx.
 

You can perform a local untrim on faces. Three modes of selection are available:

  • Selection of the face: the initial surface is restored:

  • Selection of an inner loop: only this loop is restored:

  • Selection of the outer loop: only this loop is restored:
  • If the surface has been trimmed several times, it is the initial surface which is restored. To partially untrim the surface, you need to use the Undo command right after the trim.
  • If the surface to be restored is closed (in the case of a cylinder) or infinite (in the case of an extrude), the limits of the untrim feature will be the bounding boxes of the initial surface. Therefore, the initial surface and the untrim surface may be identical.
  • You can individually select a vertex or a boundary from the restored surface or curve.
  • Multi-selection is available and allows to create several untrim features in one step. All untrim features will appear in the specification tree.
  • The keep original capability is available from the Tools Dashboard.