3D Flatness

Operator Function

Using the average point method, calculate an average point in each region, and use these average points to fit a reference plane. Calculate the peak-to-reference flatness deviation and reference-to-valley flatness deviation. The final flatness = peak-to-reference flatness deviation - reference-to-valley flatness deviation.

Reference: ISO 12781-1:2011(en) Geometrical product specifications (GPS) — Flatness — Part 1: Vocabulary and parameters of flatness

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	Image
Region Point Selection	All Points/Average Point	All Points	See Region Point Selection
Number of Regions		1	Set the number of detection regions. For Average Point mode, at least 4 ROI regions must be set and the regions cannot be collinear.
Filter Method	None/Percentile Filter	None	None: Do not use any filtering method Percentile Filter: Use percentile filtering method to filter points in each region and remove outliers. See Percentile Filter

Region Point Selection

Currently, two point selection methods are provided: All Points and Average Point modes.

Parameter	Range	Default Value	Description	Image
All Points			In this mode, all points in the ROI participate in flatness calculation.
Average Point			In this mode, the average point of all points in each region is calculated, and then the average point is included in the calculation.

Note: The average point flatness calculation method, on one hand, preserves the statistical information of all points in the region, to some extent suppressing the influence of noise points, making the calculation results more stable; on the other hand, since only average points are used for calculation, it is also faster. However, if using the Average Point mode, at least 4 ROI regions must be set and the regions cannot be collinear.

Percentile Filter Mode

If enabled, percentile filtering will be performed on points in each region.

Parameter	Range	Default Value	Description	Image
Low Percentage			Calculate the low threshold in the Z direction based on the input percentage, removing all points below this threshold
High Percentage			Calculate the high threshold in the Z direction based on the input percentage, removing all points above this threshold

Result Display

Parameter	Range	Default Value	Description	Illustration
Height	true/false	false	Region height value. If enabled, display in the image
Height Measurement Points	true/false	false	Height position points. If enabled, display in the image
ROI Point Set	true/false	false	Region point set selected by ROI box. If enabled, display 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 a warning false indicates no warning
Message	string		Output success, error, or warning messages
Time	float		Operator execution time, unit: ms
region_height	float[]		Region height array
flatness_value	float		Flatness value

Exception Troubleshooting

No.	Exception Information	Corresponding Parameter	Solution
1	High and low percentages cannot both be 50.0		Adjust high and low percentages, cannot both be 50
2	Input value is {0}, invalid height statistics method	Height Mode	Only Minimum, Maximum, Mean, Median supported
3	Global flatness test failed		1. Check if input point cloud is empty 2. Check if high and low percentages are both greater than 0 and less than 50
4	At least 4 regions need to be set in this mode		Select at least 4 different regions, and the center points of the regions should not be on a straight line
6	Input value is {0}, invalid region point selection method	Region Point Selection	Only All Points, Single Average Point supported

Example Introduction

Engineering Design

1. Select the 3D Load Point Cloud tool.
2. Select 2 Call Program tools to perform position adjustment and plane fitting respectively.
3. Select 2 3D Flatness tools, using Average Point mode and All Points mode respectively.

Tool Usage

1. Select the IM number of the input image.

2. Set the parameters.

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

4. If there are no issues, click Save. Run the operator in the run list, and then view the running results in the corresponding IM.