About Geometry Extraction

You can extract the elements and subelements from the surface and volumes. Here is a basic information required when extracting elements.

This page discusses:

See Also
Extracting Elements
Extracting Sub-Elements

Complementary Mode

Select the Complementary mode check box to highlight and therefore select the elements that were not previously selected, while canceling the selection of the elements that were explicitly selected.

Important:
  • This option is unavailable if the extracted element is a point or a volume.
  • If the selected element has a defined support and is not a surface, even though the Complementary mode check box is selected, it is not considered for the extraction. Therefore the option is inactive. After the extraction, the option is again available.
  • For the Multiple Extract command, this option applies to all the inputs that lie on the same support.

Parameters for Curves

Click Show parameters>> to display further options, applicable to curves only.

  • Distance Threshold: specifies the distance value between 0.001mm and 0.1 mm below which the elements are extracted.
    Important:
    • The default value is 0.1mm, except if a Merging Distance has been defined different from 0.001mm in Me > Preferences > App Preferences > 3D Modeling > 3D Modeling Core > Generative Shape Design, General tab. In this case, the Distance Threshold value is initialized with the Merging Distance value.
    • This option is available with all propagation types, except for the No propagation type.
  • Angular Threshold: specify the angle value between 0.5 degrees and 5 degrees below which the elements are extracted (the default value is 0.5deg).
  • Curvature Threshold: specifies a ratio between 0 and 1 which is defined as follows:

    if ||Rho1-Rho2|| / max (||Rho2||,||Rho1||) < (1-r)/r where Rho1 is the curvature vector on one side of the discontinuity, Rho2 the curvature vector on the other side, and r the ratio specified by the user; then the discontinuity is smoothed.

    For instance, r=1 corresponds to a continuous curvature and r=0.98 to the model tolerance (default value). A great discontinuity requires a low 'r' to be considered.

    Curvature Threshold = 0.98

    Curvature Threshold = 0.80

    Curvature Threshold = 0.50

Tips:
  • When Point continuity is selected, only the Distance Threshold is activated
  • When Tangent continuity is selected, both Distance and Angular Thresholds are activated
  • When Curvature continuity is selected, Distance, Angular, and Curvature Thresholds are activated.

Context Extracts

Some commands allow the creation of context extracts using the context menu of the Curve box. They are aggregated to the feature using them and put in No Show.

  • If you select the Create Extract from the context menu, the Extract Definition dialog box appears.
  • If you select the Create Extract (in point) or Create Extract (in tangency) from the context menu, no dialog box appears.
  • If you select the Create Multiple Extract from the context menu, the Multiple Extract Definition dialog box appears.
Important:
  • These commands let you create extracts with a predefined propagation. Select a subelement such as a surface edge, border edges, face, subelements of a volume or a solid.
  • You need to leave the pointer on the preselected subelement to preview and compute the propagation (in green):

Internal Edges and Support

If you extract an internal edge, you are advised to select a support element so that the orientation of the resulting extract feature remains the same even if the geometry is modified. If you extract an internal edge using the Point Propagation type and there is an ambiguity about the propagation side, a warning message is issued and you are prompted to select a support surface. In this case, the Support box becomes active.

Important: If the selected element is a border edge, the propagation is done along the boundary of the support and does not take into account internal edges.

User Selection Filter

If either Intersection edges activation or Tangent Intersection edges activation is selected in the App Options panel before launching the Extract command, then Geometrical Element Filter is automatically activated and the Propagation enter set in the Extract Definition dialog box is applied.

Deactivate Geometrical Element Filter to take into account the behavior of the Intersection edges activation or Tangent Intersection edges activation capability.

When you click OK in the Extract Definition dialog box, the status of Geometrical Element Filter returns to normal.

For further information, refer to 3DEXPERIENCE Native Apps: Selecting Using a Filter.

Extraction of Volumes

You can extract the elements from volumes. To do so, you can:

  • Select the volume in the tree
  • Use the User Selection Filter in the App Options panel and select the Volume Filter mode. For further information, refer to 3DEXPERIENCE Platform User's Guide: Selecting Using a Filter.

In both cases, the result of the extraction is the same whatever the chosen propagation type.

Color Management

When creating an Extract or Multiple Extract, it is possible to apply a color on these features. All their subelements are colored accordingly. This affects the display in the work area.

This behavior applies only on new parts. When creating Extract or Multiple Extract in parts created before 3DEXPERIENCE R2015x, the old algorithm for colors management is used. It is possible to upgrade the colors algorithm in the properties of the mechanical part. The Upgrade option is available in the Color version area in the Colors tab in the Properties dialog box.

Recognition context

You can select a recognition context for the Depression/Protrusion propagation types.

The industries proposed have specific ranges which are subject to change, in particular Ship Building's one:

Definition of Feature's industry's fillets radii range Definition of Feature's industry's chamfers lengths range
Industry Fillets range Industry Chamfers range
Power Train 0mm - 15mm Power Train 0mm - 15mm
BiW (Body in White) 1mm - 100mm BiW (Body in White) 1mm - 100mm
Consumer Goods 0mm - 50mm Consumer Goods 0mm - 50mm
Ship Building 0mm - infinity Ship Building 0mm - infinity
High Tech 0mm - 1.5mm High Tech 0mm - 1.5mm
Building 1mm - 100mm Building 1mm - 100mm
Machine Design 0mm - 15mm Machine Design 0.03 mm - 1.5mm

angles range:

30deg - 60deg

Miscellaneous

In a document containing several 3D shapes, you can use the multiple extract capability in the current 3D shape from the selection of an element in another 3D shape, provided the propagation type is set to No Propagation. In this case, a curve (respectively a surface or point) is created in the current 3D shape if the selected element is a curve (respectively a surface or point); the parent therefore being the created curve (respectively the surface or point).

Important:
  • If another propagation type is selected, the extraction is impossible and an error message is issued.
  • When editing the extract, you can change the propagation type providing the parent belongs to the current 3D shape.
  • In the current 3D shape, if you select an element using the Tangent, Point or Curvature continuity as the Propagation type, a warning is issued and you have to select No propagation instead.
  • If the selected element is not continuous in tangency and the propagation type is set to Tangent continuity, an error message is issued.
  • If the selected element is a wire that is not curvature continuous and the propagation type is set to Curvature continuity, an error message is issued.
  • When the result of an extract is not connected (during creation or editing), you can now select the part to keep solving the ambiguity.
  • If two elements have a same name and their centers of gravity are distant of less than 0.1mm, the naming ambiguity mechanism fails and an error message is issued.
  • You cannot copy an extracted element from a document to another. If you want to do so, you need to copy/paste the initial element first into the second document then perform the extraction.
  • If there are several solutions for the propagation, the computation of the extract stops at the junction point.