Inquire Edges on Tessellated Data

 

Invoked ByPoint Cloud Tool Tab

 

Inquire Tessellated Edge DataUse this command to trace "open" or "sharp" edges from a tessellated point cloud or STL data and output a set of line segments coinciding with the traced edges.  This can be used to quickly trace boundary edges or holes from a set of tessellated data or as a starting point for the manual tracing stage.  These edges can then become the "boundary edges" for the Collect Nodes from Tessellated Data command.  Select a tessellated point or an STL block as the Required Input.

 

Inquire Edges on Tessellated Data

 

 

Optional Inputs are documented here.Optional Inputs

 

Edge Type

Use this option to set the edge type to inquire for.  Select Open or Sharp.  If Sharp is selected, use the Angle option below.

 

Open Edge

Open edges are edges that are not shared between two triangles. Usually, open edges form the boundary of the tessellated triangle set, and holes and gaps on the surface, as shown in Figure 1 (Orange outline denotes traced open edges).

 

Sharp Edge

These are edges that are shared by two triangles. Therefore, an open edge cannot be a sharp edge. Furthermore, the "sharpness" of such an edge is user definable. Figures 3, 4,5 show all traced "sharp" edges at given angle values of 5 degrees, 45 degrees and 89 degrees. The higher the number, only the edges with the most acute angle value between their adjacent triangles get traced.
 

These settings may be used to find edges that define certain features such as faces and holes on a tessellated part to be used as trim boundaries for fitted surfaces without having to draw them manually. This usually works better with prismatic parts, but can be also used on free form tessellated surfaces as a starting point.

 

Figure 1. Part with open edges, typically boundary edges and holes (shown in Orange outline)
Figure 1. Part with open edges, typically boundary edges and holes (shown in Orange outline)

 

Figure 2. Part with no open edges
Figure 2. Part with no open edges

 

Figure 3 Traced “sharp” edges at given angle value of 5 degrees. Notice most non-co-planar tessellated edges are detected.
Figure 3. Traced "sharp" edges at given angle value of 5 degrees. Notice most non-co-planar tessellated edges are detected.

 

Figure 4. Traced "sharp" edges at given angle value of 45 degrees. Notice only edges that are "sharper" than 45 degrees are traced, which excludes filleted edges.
Figure 4. Traced "sharp" edges at given angle value of 45 degrees. Notice only edges that are "sharper" than 45 degrees are traced, which excludes filleted edges.

 

Figure 5 Traced "sharp" edges at given angle value of 89 degrees. Notice only edges that are close to 90 degrees are traced, even excluding some non-filleted edges from the top most face.
Figure 5. Traced “sharp” edges at given angle value of 89 degrees. Notice only edges that are close to 90 degrees are traced, even excluding some non-filleted edges from the top most face.

 

Angle

Use this option to set the angle range to check for.  This is used with the Sharp Edge Type above.

 

 

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