Splitting and Trimming Geometry (common options)

There are options that are common to both Split and Trim (Standard mode) commands.

This task shows you how to:

See Also
Splitting Geometry
Trimming Geometry

Keep and Remove Elements

The Elements to remove and Elements to keep options allow to define the portions to be removed or kept when performing the split operation.

  1. In the Elements to keep box, select the elements to keep.
    The selected elements are kept. All other elements are removed.

  2. In the Elements to remove box, select the elements to remove.
    Only the selected element is removed. All other elements are kept.

    Notes:
    • Right-click in the box to clear the selection.
    • Click to display the list of selected elements.
    • You can select sub-elements as elements to keep or to remove:

    • You can also select a point to define the portion to keep or to remove.
    • You do not need to select elements to keep if you already selected elements to remove and vice-versa.
    Important:
    • Avoid trimming geometry when the intersection between the trimmed elements is merged with an edge of one of the elements.

      In that case, you can use the Elements to remove and Elements to keep boxes to remove the position ambiguity.

    • If the intersection between the elements is not connected, an error message may be issued prompting you to choose the elements to be kept or not.

Compute Intersections

You can compute the intersection of the surfaces by selecting Intersections computation check box.

By default, this option is not selected.

Select the Intersections computation check box to create an aggregated intersection when performing the trimming operation. This element will be added to the tree as Intersect.xxx.


Important: If there are several elements to cut, the Intersections computation check box only applies on the first selected element.

Select a Support

When splitting or trimming wires (curve, line, sketch and so forth) by another wire, you can select a support to define the area that will be kept after splitting or trimming the element.

It is defined by the vectorial product of the normal to the support and the tangent to the splitting or trimming element.

This is especially recommended when splitting or trimming a closed wire. Here, the sketch composed of two lines is trimmed by the circle.



Select a support.


Here is the result when no support is selected:

Split/Trim Closed Surfaces by Two connected Surfaces or Curves

When splitting a closed surface or a curve by connected elements, an error message is issued. You need to create a join feature of non connected elements and cut the closed surface or curve with this join feature.



  1. Click Join .
    The Join Definition dialog box appears.
  2. Select the surfaces to be joined.
    Ensure that both the surfaces or curves to be joined have coherent orientations. If it is not the case, use the Invert Orientation command to invert the orientation of one of the two surfaces or curves.
    Note: Coherent orientations mean same orientations as the faces or edges of an equivalent connected splitting surface or curve:

  3. Clear the Check connexity check box.
  4. Click OK to create the joined surface.
  5. Click Split or Trim .
    The Split Definition or Trim Definition dialog box appears.
  6. Select the surface as the Element to cut and the join elements as the Cutting element or the surface and the join elements as the Trimmed elements.
  7. Click OK to split or trim the closed surface.
    Important:
    • If the orientation of the elements composing the joined surface or curve is incoherent, an error message is issued.
    • In case the intersection between the elements is not connected, an error message may be issued informing you to choose the elements to be kept or not.

      In this case, use the Elements to remove and Elements to keep options

Split/Trim a Surface when Elements are Tangent to Each Other

Splitting a surface by another surface one requires the computation of the surface intersection. When the surfaces to be intersected are tangent, there are ways to avoid intersections.

Whenever possible, intersections and input elements that are tangent to each other should be avoided.

Similarly, the following cases should be avoided when possible (especially when the tangency constraint between the two surfaces has not been clearly defined by the user during the surface creation), as the result of the positioning is likely to be indeterminate and the result of the intersection to be unstable in the tangency zone.

Here is an example of tangent surfaces:

Split/Trim a surface when boundaries are in contact

You can split/trim the surface by joining them.

  1. Click Join .
    The Join Definition dialog box appears.
  2. Select the surfaces to be joined.


Split/Trim a surface when one portion of the surface is to be removed

You can split/trim a surface when one portion of the surface is to be removed.

  1. Extract the sweep boundary which is located on the extruded surface.
  2. Use the extract element to split/trim the extruded surface.
  3. Join the swept surface and the split/trim result.


Split/Trim a surface when surfaces are tangent or intersect face edges

You can use the border edge of the cutting surface to split the element to cut or trim the element.

  1. Delimit the boundary of the cutting surface.
  2. Project this boundary onto the surface to split.
  3. Use this projection as the cutting element.
    The last two steps may be optional if the tangency constraint between the two surfaces has been clearly defined by the user during the surface creation.

Split/Trim Non-Intersecting Elements

You can split/trim non-intersecting elements by projecting the points on the surface to be cut.

In the example below, the distance between the circle and the line is greater than the resolution but less than 0.01mm. There is a way to split/trim the line and obtain a result with no gap.

  1. Project the point that is liable not to be on the wire to be split/trimmed, on the line.


  2. Use the projected point as the splitting/trimming element.