3D Coplanarity - Datum Plane Method

Operator Function

Use the datum plane method to calculate coplanarity deviation

Principle Explanation:

1. Extract the highest points of each terminal point cloud
2. Determine three terminal vertices exhibiting the maximum vertical distance (the terminal triangle defining the datum plane must contain the projection of the centroid to form a valid datum plane. If the plane is not considered valid, the next terminal with the maximum vertical distance will be considered as a candidate terminal to form a valid datum plane)
   
3. Calculate the datum plane from the three vertices
4. The coplanarity deviation requires calculating the distance from the datum plane to each terminal vertex, where the maximum measured value is the coplanarity deviation:
   

Parameter Introduction

Input Parameters

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

Calculation Parameters

Parameter	Range	Default Value	Description	Illustration
Region	2D Window/2D Circular Window/2D Polygon Window/Box/Cylindrical Box/Rotated Box/Point Set (binding only)	Box	Manually select appropriate ROI region Can bind to select existing ROI region
Terminal Settings			Set parameters for terminal segmentation
Minimum Terminal Spacing	0.0-1000000.0	0.1	Minimum spacing to distinguish different terminals
Minimum Points Per Terminal	1-1000000	100	Limit the minimum number of points in terminal point cloud
Maximum Points Per Terminal	1-1000000	10000	Limit the maximum number of points in terminal point cloud

Result Display

Parameter	Range	Default Value	Description	Illustration
Vertices	true/false	false	Highest points of each input point cloud. If enabled, display in the image
Center	true/false	false	Centroid of all terminal point clouds. If enabled, display in the image
Datum Plane	true/false	false	Plane formed by three qualified terminal vertices. If enabled, display in the image
Coplanarity Deviation	true/false	false	Calculated coplanarity value. If enabled, display in the image
Vertex Triangle	true/false	false	Triangle formed by three qualified terminal vertices

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 no warning
Message	string		Output success, error, or warning messages. Empty if no error or warning
Time	float		Operator execution time, unit: ms
coplanarity_deviation	float		Coplanarity

Tip

For more detailed explanations of parameter types, please refer to Type Definitions

Exception Troubleshooting

No.	Exception Information	Corresponding Parameter	Solution
1	Input point cloud is empty		Confirm if IM contains valid points. If no valid points, load point cloud or switch to IM with valid points
2	Input region type is {0}, invalid region type	Region Type	Region input type must be one of: 2D Window/2D Circular Window/Box/Cylindrical Box/Rotated Box/Point Set
3	Region is empty		Check if input ROI selects at least 4 point clouds
4	Number of detected terminals is {0}, at least 4 terminals required	Region Count	Check input point cloud or terminal setting parameters: terminal point limits or minimum terminal spacing
5	Input polygon vertex count is less than 3, cannot form polygon		Add 2D polygon window vertices so that vertex count is at least three
6	No set of terminal vertices meets requirements		-
7	Input terminal point limit is invalid		Set upper limit of terminal points to be greater than or equal to lower limit

Example Introduction

Engineering Design

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

2. Select the 3D Coplanarity - Datum Plane Method tool, set different output types.

Tool Usage

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

2. Bind the point cloud arrays to be measured.

3. Set the parameters.

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. Run the operator in the run list, and then view the running results in the corresponding IM.