Insert Edge

Semi-automatic tracing of lines along edges in LiDAR data. The user roughly identifies two points along the edge and the algorithm traces it in both directions until termination/failure. The result can be interactively navigated for quality control and possible editing.

Insert Edge is designed to work with LiDAR and point cloud data. This application may be started from a Function Key.

When Insert Edge starts, initial points along the edge line need to be digitized. This initial data provides seed information so the application can follow the edge and place a 3D line.

	Button	Description
1	Initial point	Identifies two points along the edge to provide initial data to start the edge line insertion.
2
3	Review line	Review an existing line
4	Extend/hack	Extend or hack an existing line
5	Join lines	Joins two existing lines using a user defined join point
6
7	Enter params	Enter/edit Insert Edge parameters (see Insert Edge Parameters)
8	Del last line	Deletes the last saved line
9	Del line	Deletes a line by identifying an existing line
*
0
#	End	Ends application

	Button	Description
1
2	Next point	Moves cursor to the next line point
3	Prev point	Moves cursor to the previous line point
4	First point	Moves cursor to the first point on the line
5	Last point	Moves cursor to the last point on the line
6
7
8
9
*
0
#	End	Ends review and returns to the main menu

The cursor may be placed near an existing line and the closest line will be extended to or hacked at the point digitized (the hack point). If the line is to be extended the endpoint on the line will be extended along the azimuth of the last line segment. If the line is to be hacked the shortest side of the line will be hacked at a 90 degree offset from the hack point. After the hack point has been digitized and the line extended or hacked, the result may will be displayed and may be accepted or rejected before re-saving the line.

	Button	Description
1	Dig hack pt	Digitizes the hack point when extending or hacking a line
2
3
4
5
6
7
8
9
*
0
#	End	Ends Extend/hack and returns to the main menu

Two existing lines may be joined by placing the cursor near both lines and digitizing a point (the join point). The join point will be the common point between the two lines. Lines will be extended or hacked to the join point. After the join point has been digitized and the lines joined, the result may will be displayed and may be accepted or rejected before re-saving the lines.

	Button	Description
1	Dig join pt	Digitizes the join point when joining two lines
2
3
4
5
6
7
8
9
*
0
#	End	Ends Join Lines and returns to the main menu

Deletes an existing line. When a line is identified to be deleted it may be accepted or rejected before deletion.

	Button	Description
1	Id line	Identifies the line to delete
2
3
4
5
6
7
8
9
*
0
#	End	Ends Delete Line and returns to the main menu

The Insert Edge parameters may be defined by pressing button 7 from the Main menu.

Defines a cylinder around the edge line used for processing. The planar faces of the break should extend somewhat beyond this distance. (ground, default=0.5)

Provides a limit to how close planes on either side of the edge line are allowed to get to parallel. (degrees, default=15)

The algorithm follows an edge line by modeling it as intersecting planes. The angle between the plane normals describes the shape of the edge. The Maximum Change parameter limits how much change in the shape will be tolerated before stopping. (degrees, default=15)

The maximum number of points to use in processing a segment of an edge line. This allows the processing to remain reasonably time stable in very dense data. (default=500)

Search radius and endpoint extend distance when searching for lines to join or extend. (ground, default=10)

The following key-ins may be used to change run-time parameters. They may be keyed in, placed in macros or more commonly placed in the Local Args field in a Function Key.

Key-in	Description	Range
Lay=	Layer number	1-32001
Mod=	Mode	1=Line 2=Spline
Grp=	Graphic pointer	1-1000
Wid=	Line width	0-255
Pen=	Pen number	1-256
Con=	Construction flag	0-1
Ngr=	Non graphic pointer	32-bit
Lnk=	Link number	32-bit
Fc=	Feature code	15 char

MaxDis=	Distance around edge	ground (default=0.5)
MinAng=	Minimum angle between plain normals	degrees (default=15)
MaxCha=	Maximum change in angle between planes	degrees (default=15)
MaxPts=	Maximum number of points for processing	(default=500)
LinSea=	Line search radius	ground (default=10)