🔷Point Cloud Edge Extraction (Meridional Scanning Method)

Function Description

This operator extracts the external contour edge points of the input point cloud on the XOY plane through a "scan line" approach. First, it determines the range of the point cloud on the X-axis and Y-axis, then divides the X-axis range into several intervals according to the set "resolution" parameter, finding the points with maximum and minimum Y coordinates within each interval; similarly, it divides the Y-axis range into intervals and finds the points with maximum and minimum X coordinates within each interval. Finally, all these found maximum/minimum points are merged together as the extracted edge point cloud.

This method is mainly used to extract the outermost contour of point cloud projection on the XOY plane, particularly suitable for point clouds whose shape approximates a plane and whose main projection surface is close to the XOY plane.

Usage Scenarios

  • Extract Planar Contours: Obtain external boundaries of flat objects (such as plates, components) on the XOY plane.

  • Obtain 2D Envelopes: Get the approximate envelope range of point clouds on a two-dimensional plane.

  • Simplify Edge Representation: For application scenarios with complex internal structures but only requiring external contours.

Input Output

Input

Point cloud: Input point cloud or point cloud list.

CalculateEdgeByScan input

Output

Point cloud edges: List of point clouds composed of extracted edge points.

CalculateEdgeByScan output

Parameter Description

This operator has two versions:

  • Point Cloud Edge Extraction (Meridional Scanning Method): Processes point clouds without normal information.

  • Point Cloud with Normals Edge Extraction (Meridional Scanning Method): Processes point clouds with normal information.

Both have identical core functionality and parameters, differing only in the type of point cloud data processed.

Resolution

Parameter Description

The number of scanning segments in the X-axis and Y-axis directions, determining the fineness of scanning.

Parameter Adjustment

  • Increasing this value: Will divide the X-axis and Y-axis ranges into more and smaller intervals, making scanning denser, and the extracted edge points will be denser too, able to describe contour details more precisely, but computational load will increase.

  • Decreasing this value: Intervals become larger, scanning becomes coarser, extracted edge points will be sparser, may lose some contour details, but computation speed is faster. Needs to be adjusted according to point cloud size, shape complexity, and expected edge point density.

Parameter Range

[0, 1000], default: 100

CalculateEdgeByScan 1

CalculateEdgeByScan output

CalculateEdgeByScan 2

Resolution=500

Resolution=800

Resolution=1000

Enable Node

Parameter Description

Controls whether this operator executes computation.

Parameter Adjustment

  • Enable (default): Run this operator’s functionality normally.

  • Disable: The operator performs no operations and directly outputs the input data.