OOF2: The Manual

Edge boundary from segments (EdgeFromSegments)
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Name

Edge boundary from segments (EdgeFromSegments) — Construct an edge boundary from a set of segments.

Synopsis

EdgeFromSegments(group, direction)

Details

  • Base class: BoundaryConstructor

  • Parameters:

    group
    Construct the boundary from these segments Type: The name of a segment group, or the placeholder selection, referring to the currently selected segments.
    direction
    Direction of the boundary. Type: An object from the Director enumerated class.

Description

EdgeFromSegments is a BoundaryConstructor, used as the constructor argument of the OOF.Skeleton.Boundary.Construct command when building Skeleton boundaries. It creates Edge Boundaries from the currently selected Skeleton Segments or from a group of Segments. The Segments are specified by the group parameter, which must be either the name of a Segment group or the special placeholder object, selection.

Edge boundaries must be constructed from a single contiguous non-branching set of Segments, and they must be directed. Boundary conditions use the direction to determine the boundary normal and the direction of applied Fields and Fluxes. The direction parameter specifies the direction of the boundary being created. The legal values for direction depend on the topology of the boundary being constructed. When the Segments form a closed loop, the legal values are 'Clockwise' and 'CounterClockwise'. When the Segments form an open line or curve, the values are 'Left to right', 'Right to left', 'Top to bottom', and 'Bottom to top'. OOF2 compares the positions of only the first and last Nodes when determining the direction of an open boundary.

Figure 6.79. Constructing an Edge Boundary from Segments

Constructing an Edge Boundary from Segments

(a) A closed loop of Segments on the border of the blue region has been selected.[32]

(b) the selected Segments have been turned into a closed clockwise edge boundary by 

          OOF.Skeleton.Boundary.Construct(
             skeleton='swoops.png:skeleton',
             name='boundary',
             constructor=EdgeFromSegments(group=selection, direction='Clockwise'))

(c) The dialog box offers clockwise and counterclockwise directions because the Segments form a loop.

Constructing an Edge Boundary from Segments

(d) Segments on the border between the red and white Elements have been selected.[33] They don't form a closed loop.

(e) The selected Segments have been turned into an open linear edge boundary by 

          OOF.Skeleton.Boundary.Construct(
             skeleton='swoops.png:skeleton',
             name='boundary<2>',
             constructor=EdgeFromSegments(group=selection, direction='Left to right'))

(f) The possible directions are left to right, right to left, etc, because the Segments form an open sequence.

Constructing an Edge Boundary from Segments

(g & h) The selected Segments in these two examples cannot be assembled into a simple sequence.

(c) The dialog does not offer any direction and the OK button is disabled.


See Also


[32] They were selected by creating an Element group for the blue Elements and using OOF.SegmentSelection.Select_from_Selected_Elements.

[33] A circular Active Area was created enclosing the red pixels, and OOF.SegmentSelection.Select_Internal_Boundary_Segments was used to select the Segments.

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