Extract Surface Section
Description
This Step is used to extract a profile from the surface data. You can form a plane perpendicular to the XOY plane by the connecting line of two feature points on the surface or the center line of the set feature region. The intersection of the formed plane with the surface data can produce a section profile.
The extracted section profile may have a specific orientation, but the output profile of this Step is on the XOZ plane, starting with X = 0.
|
|
Uses a feature region to extract a section profile |
Profile output by the Step |
Workflow
The process of configuring this Step is shown below.
-
Configure the input. Connect the Step ports in the graphical programming workspace or select the input under Input in the parameter configuration panel.
-
Set Sectioning Mode.
-
Set other parameters.
-
Select the desired output items under Output. For an expandable output item, click ▶ and configure the Min and Max values to determine the acceptable range for the item.
Parameter Description
First, it is necessary to confirm Sectioning Mode, namely the method of extracting a section profile from surface data. You can select Feature region or Feature points.
-
Define a feature region on the surface, and a plane perpendicular to the XOY plane and passing through the center line of the region will be formed to intersect with the surface data and thus produce a section profile (the red lines shown in the figure below). The center line of the feature region is the line initially connecting the midpoints of two edges along the Y-axis.
See Feature Region to learn about how to adjust a feature region. 
2D image
3D image
-
Select two data points from the surface data as feature points. The plane perpendicular to the XOY plane and passing through the two feature points is thus formed to intersect with the surface data, generating a profile (the red lines shown in the figure below). The endpoints of the profile are the two feature points (the two yellow dots shown in the figure below).
In this case, two feature points are the required input of the Step. You need to connect the ports manually or configure the input under Input.
2D image
3D image
|
Feature points provide precise positional information, specifying the endpoints of an intersection to form a plane perpendicular to the surface. It is preferable to use feature points when you already know exactly where the endpoints are located. Feature region helps you define the position of the sectioning plane more flexibly. If you want to extract the profile from a wide region and do not need to specify endpoints, a feature region may be a better choice. |
Next, adjust corresponding parameters according to the selected sectioning mode.
The Sectioning Mode Is “Feature Region”
| Parameter | Description | ||
|---|---|---|---|
Feature Region |
The region for extracting a profile from surface data. Visible only when the “Sectioning Mode” is set to Feature region. See Feature Region to learn about how to adjust a feature region. |
||
Average Profiles |
If the parameter is not selected, a profile will be generated with the raw data points (which may be empty) on the intersection directly without averaging. If the parameter is selected, the average Z value of the data points is calculated within the length of the feature region, along the direction perpendicular to the center line of the feature region. The averaged data points (which may be empty) form a profile.
|
||
Min Valid Points |
Visible only when the Average Profiles parameter is selected. This parameter is used to specify the percentage of valid points within the length of the feature region. When the actual percentage of valid points is lower than this value, the data point on the profile will be judged as non-existent.
|
||
Show Detail |
Once this setting is enabled, the generated profile will be displayed on the original data. |
The Sectioning Mode Is “Feature Points”
| Parameter | Description | ||
|---|---|---|---|
Average Profiles |
If the parameter is not selected, a profile will be generated with the raw data points (which may be empty) on the intersection directly without averaging. If the parameter is selected, the average Z value of the data points is calculated within Averaging Width, along the direction perpendicular to the line connecting the two feature points. The averaged data points (which may be empty) form a profile. |
||
Averaging Width |
The pixel width considered when performing averaging along the direction perpendicular to the line connecting the two feature points. Visible only when the Average Profiles parameter is selected. |
||
Min Valid Points |
Visible only when the Average Profiles parameter is selected. This parameter is used to specify the percentage of valid points within Averaging Width. When the actual percentage of valid points is lower than this value, the data point on the profile will be judged as non-existent.
|
||
Show Detail |
Once this setting is enabled, the generated profile will be displayed on the original data. |
Output Description
Select the output item(s) to add the output port(s) to the Step, and the corresponding data will be output after the Step is run. You can select the output according to the actual measurement requirements.
|
If you select an expandable output item, you must expand it by clicking ▶, and then set the Min and Max values to determine the acceptable range. If the output value falls within the acceptable range, the measurement item is judged as passing (OK), or else it is judged as failing (NG). |
| Output Item | Description |
|---|---|
Profile |
The resulting profile. |
Start X |
The X coordinate of the start point of the profile. |
End X |
The X coordinate of the end point of the profile. |
Start Y |
The Y coordinate of the start point of the profile. |
End Y |
The Y coordinate of the end point of the profile. |
Rotation Angle |
The rotation of the extracted profile counterclockwise around the Z-axis (the angle between extracted profile and positive X-axis). |
Troubleshooting
|
CV-W2201
Error: The “Min Valid Points” value is not within [0, 1].
Possible cause: The set value of min valid points is not within [0, 1].
Solution: Reset Min Valid Points and ensure that the value is within [0, 1].