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AVL.ScanMultipleEdges3D

Locates multiple changes of surface height along a given path.

Namespace:AvlNet
Assembly:AVL.NET.dll

Syntax

C++
C#
 
public static void ScanMultipleEdges3D
(
	AvlNet.Surface inSurface,
	AvlNet.ScanMap inScanMap,
	AvlNet.EdgeScanParams3D inEdgeScanParams,
	float inMinDistance,
	float? inMaxDistance,
	AvlNet.LocalBlindness? inLocalBlindness,
	int? inMaxProfileGapWidth,
	IList<AvlNet.SurfaceEdge1D> outEdges
)

Parameters

Name Type Range Default Description
inSurfaceAvlNet.SurfaceInput surface.
inScanMapAvlNet.ScanMapData precomputed with CreateSurfaceScanMap.
inEdgeScanParamsAvlNet.EdgeScanParams3DParameters controlling the surface edge extraction process.
inMinDistancefloat<0.0f, INF>Minimal distance between consecutive edges.
inMaxDistancefloat?<0.0f, INF>Maximal distance between consecutive edges. Default value: atl::NIL.
inLocalBlindnessAvlNet.LocalBlindness?Defines conditions in which weaker edges can be detected in the vicinity of stronger edges. Default value: atl::NIL.
inMaxProfileGapWidthint?<0, INF>Maximal number of consecutive not existing profile points. Default value: atl::NIL.
outEdgesSystem.Collections.Generic.IList<AvlNet.SurfaceEdge1D>Found surface edges.

Description

The operation scans the surface using inScanMap previously generated from a scan path and detects surface edges perpendicular to the path. Depending on the inEdgeScanParams.edgeTransition parameter, edges representing increase or decrease (or both) of surface height along the path will be taken into account.

When the number of edges to be found is known, one can use the ScanExactlyNEdges3D.

Note that in case of a scan path which is closed, the parameters controlling the distances between consecutive found objects do not control the distance between the first and the last of the found objects (counting from the beginning of the scan path).

The operation is very similar to ScanMultipleEdges from 1DEdgeDetection category, but there are some substantial differences. One of these is the possibility of absence of information, because some surface points may not exist at all. To detect such edges, where solely change of existence matters, Valid/Invalid options of inEdgeScanParams.EdgeTransition can be used. Outside the surface domain (i.e. rectangle defined by input surface width, height, offsets and scales) there are no valid or invalid points, so no edge can be found in the direct vicinity of the domain border.

Please note that when the input surface has unequal scales along X and Y axes and the scan path is not parallel to any of the axes, the results may be slightly less accurate because of uneven sampling along axes.

Remarks

Read more about Local Coordinate Systems in Machine Vision Guide: Local Coordinate Systems.

Function Overrides

See also