3D Line-Plane Parallelism

Operator Function

Calculate the geometric tolerance - line-plane parallelism

As shown in the figure below, compute the perpendicular distance 𝑑1, 𝑑2, …, 𝑑n from each measurement point on the measured plane to the datum axis. The parallelism is:
𝑑𝑚𝑎𝑥 − 𝑑𝑚𝑖𝑛
where
𝑑𝑚𝑎𝑥 = 𝑚𝑎𝑥(𝑑1, 𝑑2, …, 𝑑n)
𝑑𝑚𝑖𝑛 = min(𝑑1, 𝑑2, …, 𝑑n)

Parameters

Input Parameters

Parameter	Range	Default	Description	Diagram
Input Image	0-8	0	IM index of the input image

Calculation Parameters

Parameter	Range	Default	Description	Diagram
Actual Plane	Plane	-	A point on the actual plane and its normal vector
Datum Line	3D Line	-	A point on the datum line and its direction vector
Measurement Point File	json file	-	Measurement point file on the measured plane
Use Region Parameter	true/false	false	When enabled, use Region as input; when disabled, use Input Image as input
Region	2D Window / 2D Circular Window / 2D Polygon Window / Box / Cylinder Box / Rotated Box / Point Set (binding only)	Box	Manually select a suitable ROI region You can select an existing ROI region by binding
Auxiliary Vector	3D Vector	-	A vector not parallel to the line, used to assist in obtaining the normal vector

Result Display

Parameter	Range	Default	Description	Diagram
Actual Plane	true/false	false	The input actual plane; when enabled, displayed on the IM
Datum Line	true/false	false	The input datum line; when enabled, displayed on the IM
Intersection Points	true/false	false	Display two sets of points: the input measurement points and the feet of perpendicular from the measurement points to the actual plane; when enabled, displayed on the IM
Lines Connecting Measurement Points and Their Feet on the Fitted Datum Plane	true/false	false	The lines connecting the feet of perpendicular from the input measurement points to the actual plane; when enabled, displayed on the IM
Parallelism	true/false	false	The output parallelism; when enabled, displayed on the IM

Output Parameters

Name	Type	Range	Description
Result	bool	true/false	true for success false for failure
Warning	bool	true/false	true indicates a warning false indicates none
Message	string		Output success, error, or warning message; empty if no error or warning
Time	float		Operator execution time, unit: ms
distance	float[]		Distance from measurement points to the reference plane
parallelism	float		Parallelism
result	string	OK/NG	Whether the parallelism is within range

Tip

For more details on parameter types, please refer to Type Definition

Troubleshooting

No.	Exception Message	Corresponding Parameter	Solution
1	Input point cloud is empty		Confirm whether the IM contains valid points. If no valid point exists, load the point cloud or switch to an IM with valid points
2	The type of the input actual plane is {0}, an invalid plane type	Plane Type	Check whether the plane type is a plane
3	The normal vector of the input plane is 0		Check whether the plane normal vector is all zeros
4	The minimum value of the input parallelism range is greater than the maximum, an invalid parallelism range		Set the minimum of the parallelism range to be less than or equal to the maximum
5	Parameter {0} cannot be empty	Path	Check whether the path is empty
6	File {0} does not exist or cannot be accessed	Path	Check whether the path is valid
7	The input theoretical position point cloud is empty		Check whether the theoretical position point json file is empty
8	The type of the input datum line is {0}, an invalid datum line type	Datum Line Type	Check whether the datum line type is a 3D Line
9	The input region type is {0}, an invalid region type	Region Type	Check whether the region type is one of 2D Window / 2D Circular Window / 2D Polygon Window / Box / Cylinder Box / Rotated Box / Point Set
10	The number of polygon vertices is less than 3, cannot form a polygon		Add 2D polygon window vertices so that the number of vertices is at least three
11	The input region point cloud is empty		1. Check whether the selection is empty 2. Check whether the point set is empty

Examples

Engineering Setup

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

2. Select the 3D Square Probe tool to fit the actual plane.

3. Select the 3D Square Probe tool to fit the datum line.

4. Select the 3D Line-Plane Parallelism tool.

Tool Usage

1. Select the input image to be operated on; the image index must match the IM index of the image in the project.

2. Either disable the use-region parameter, or enable the region and select the region type as Box, then move the box to the position to be measured so that it encloses the point cloud to be measured.

Usage Tips

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

3. Set the parameters.

4. Check the items to be displayed in the Result Display panel.

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

6. After confirming there are no problems, click Save, then run the operator in the run list to view the running result in the corresponding IM.