3D Square Probe

Operator Function

Search for edge points in a specific direction, returning geometric parameters such as points, lines, planes, regions, etc.

Parameter Introduction

Input Parameters

Parameter	Range	Default Value	Description	Illustration
Input Image	0-8	0	The IM number for image input

Calculation Parameters

Parameter	Range	Default Value	Description	Illustration
Region	2D Window/Box	Box	Manually select an appropriate ROI region Can bind to select existing ROI regions
Direction	+X/-X/+Y/-Y/+Z/ -Z/Select All Points	Select All Points	Select search direction +X: Search along positive X-axis -X: Search along negative X-axis +Y: Search along positive Y-axis -Y: Search along negative Y-axis +Z: Search along positive Z-axis -Z: Search along negative Z-axis Select All Points: Select all points within ROI
Exclusion Cone Angle		45.000	The cone angle when searching along the selected direction; points outside the cone will be preserved
Resolution		1000	The reciprocal of step length when searching along the selected direction; increasing resolution means more sampling points, but also increases operator runtime.
Search Foreground Only			Whether to only search for foreground edge points; if checked, manually set Z-direction threshold to separate foreground and background.
Output Geometry	Point/Line/Plane/Segment	Line	Point: Centroid coordinate point of point cloud region Line: Contains center point of line segment and direction vector of line Plane: Contains geometric center point of plane and normal vector of plane Segment: Contains coordinates of two endpoints of line segment
Filter Method	No Filter/Statistical Filter/RANSAC Filter	No Filter	See Filter Methods

Result Display

Parameter	Range	Default Value	Description	Illustration
Point Set	true/false	false	Target point set; if enabled, displayed in the image
Point	true/false	false	Points found by the tool; if enabled, displayed in the image
Line	true/false	false	Lines found by the tool; if enabled, displayed in the image
Plane	true/false	false	Planes found by the tool; if enabled, displayed in the image
ROI Point Set	true/false	false	Point set of ROI selected region; if enabled, displayed in the image
Segment	true/false	false	Line segments found by the tool; if enabled, displayed in the image
Segment Center Point	true/false	false	Midpoints of line segments found by the tool; if enabled, displayed in the image

Output Parameters

Name	Type	Range	Description
Result	bool	true/false	true for success false for failure
Warning	bool	true/false	true indicates there is a warning false indicates there is none
Message	string		Outputs success, error, or warning information; if there is no error or warning, it is empty
Time	float		Operator execution time, unit:ms
region	pointset		Point set region
middle_point	point3d		Midpoint coordinates
Line	line3d		Line information
plane	plane		Plane information
Segment	segment3d		Line segment information
Segment Center	point3d		Line segment midpoint information

Filter Methods

Parameter	Range	Default Value	Description	Illustration
No Filter			No filtering of found edge points
Statistical Filter			This filtering method first performs a best-fit on the found edge points, then uses the standard deviation multiplication factor to calculate the distance threshold. Calculate the distance from all edge points to the fitted model; if this distance exceeds the threshold, it is considered an outlier. Standard Deviation Multiplier: Recommended range [1.0, 2.0]
RANSAC			This filtering method consists of two steps: hypothesis and verification. The hypothesis step randomly selects n points from the point set for geometric model fitting; the verification step uses the remaining points to calculate their distance to this geometric model. Points with distances less than the threshold are called inliers. If the number of inliers meets the threshold, the geometric model from this hypothesis step is considered the best model, and iteration stops. Distance Threshold: If the distance from a point to the output geometry exceeds this threshold, it will be filtered out. Iteration Count: If iteration exceeds this count, the algorithm stops.

Exception Troubleshooting

No.	Exception Information	Corresponding Parameter	Solution
1	The input value is {0}, invalid region type	Region Type	Only supports window2d, box, pointset
2	Region is empty		1. Check if input point cloud is empty 2. Check if ROI region encloses any point cloud 3. Check if bound pointset is empty
3	The input value is {0}, invalid search direction	Search Direction	Only supports +X, -X, +Y, -Y, +Z, -Z, no probing
4	Failed to search edge points		1. Check if search direction is correct 2. Check if resolution is negative; if so, change to positive
5	The input value is {0}, invalid filter method	Filter Method	Only supports No dispersion filter, Statistical outlier removal, RANSAC
6	The input value is {0}, invalid output geometry type	Geometry Type	Only supports Point, Line, Plane, Segment 3D

Example Introduction

Engineering Design

1. Select the Load 3D Point Cloud tool to load the 3D point cloud image to be processed into IM0.

2. Select the 3D Point Cloud Crop tool, copy IM0 to IM1, IM2, IM3 respectively for different operations.

3. Select the 3D Square Probe tool.

Tool Usage

1. Select the input image for operation; the image number must match the IM number where the image is located in the project.

2. Select the region type as Box, move the box to the position to be measured, enclosing the point cloud to be measured.

Usage Tips

1. Use the ROI controller on the image window to drag or scale the box;
2. Directly modify the start or end coordinates of the box in the calculation parameters to adjust the box position and size;

3. Set parameters

Select multiple 3D Square Probe tools, set output geometry to Point and Line respectively with search directions +X, +Y, -X, -Y, and set output geometry to Plane with different regions selected.

4. Check the content you want to display in the result display section

5. Click Test to check if the image window and parameters meet expectations

6. If there are no issues, click Save, then run the operator in the run list to view the results in the corresponding IM