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Menu: Survey / Edge Sidewalk detection

This tool automatically detects the

edge of a sidewalk and vectorizes the

top and bottom

edges. The first is the top edge of the sidewalk while the other is the bottom at the road level. After the detection, the “Pick points” window will appear and let the user decide whether the points must be saved in the database, exported or transferred as an alignment.

of a sidewalk and vectorizes them. The detection will create points along the edge as long as the parameters are met. This function needs a good density of points so that the edges are correctly detected.

It needs two points on an edge to start its detection. Here is a list of

Here are the parameters:

Direction tolerance

Lenght: Maximum

deviation

legnth of the

polyline from one segment to the next.

Min. segment length: Distance between each point in the polyline.

Elevation tolerance: Maximum difference of elevation from the edge for points to be considered

search box
Width: Maximum width of the search box.
Height: Maximum height of the search box. This value must be kept

low

as close to reality as possible for the

algorithm

detection to work properly

.Distance tolerance: Buffer to find

.
Seg. Length: Maximum distance for the segment to be considerate valide.
Tol. distance: Maximum tolerance to search for the next point.

If too high, the algorithm may connect different edges together. Starting point: To specify the starting point, first select the “Pick 2 Points” button and pick the point where the edge must begin and another point on the edge for global starting direction. Both coordinates will be entered

Tol.deviation: Maximum deviation from the last detected point and the next point to be considered.
Tol.verticality: Maximum angle to detect the bottm of the curb (deviation from the 90° reference).
Min. point: Minimum of points within the box to be considerate valid for the detection.
Highest points / Lowest points: Select

which chain

a Pcodes to

generate either

the top edge

, bottom edge or both edges of the sidewalk.

Starting parameters:

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Results of the detection and point management:

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& bottom edge to identify the type of element in your CAD.

Once the parameters are setup, you will have to go to "Search by" and select between 2 options.

Two points: You will pick the starting point of the detection and the 2nd point will indicate the direction to follow for the detection
By Trajectory: Select an alignment or the camera path (For MMS) for automatic batch detection. You will have to select the offset left & right (search distance from the trajectory) and the start/end of the search by entering the index number for each or clicking on the point cloud directly ( you will need to click on "Start index" and "End index" respectively prior to click on the point cloud).

Once the mode selected, then click on "Start detection"

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Once the detection is done you will have the possibilty to adjust the vectorization to fit better your point cloud. To do so, you have access to "Fitting"

Fit in XY: Straighten the lines in X & Y
Fit in XYZ: Straighten the lines in X, Y & Z
Spline: Adjust the line to follow the curb
BSpline:

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Once you are done with the detection, you will have the option to:

Save: Saves the selected polylines to a PLN format.
Load: Loads a PLN file to the item list while clearing existing items.
Append: Adds a PLN file to the item list. Does not clear existing items.
Export: Exports selected polylines to .DXF, .MID or .SHP, GeoJSON or .KML format.
Create chains: see "Picking points and lines".

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