Contour Processing Tools

The contour processing module can generate contours, create elevation annotation points, detect contour conflicts, and filter by minimum area based on the point cloud data in the scene.

Point Cloud to Contour

Generate contour lines within a selected region of the point cloud data and add them to the current editing object.

1. Click the left mouse button to select a region, double-click to finish.

2. A parameter configuration interface will appear. Set the parameters as follows:

   
   • Select Data: Ensure that each input point cloud data file has been classified. Input files can be either a single point cloud file or a dataset. The data must be opened in LiDAR360 software.
   • Scale: The scale for contour generation from the point cloud, with 11 different scales corresponding to different contour intervals.
     • 1:500: 1:500 scale.
     • 1:1000: 1:1000 scale.
     • 1:2000: 1:2000 scale.
     • 1:5000: 1:5000 scale.
     • 1:10000 (default): 1:10000 scale.
     • ... ...
   • From Class: The starting point cloud category used to construct the contours.
   • Reference Height (meters) (default "0"): The height from which contours are calculated, i.e., the height difference relative to the reference that corresponds to integer multiples of the contour interval. For example, with a reference of 0 and a contour interval of 10, the contour heights would be: 0, -10, -20, -30..., 10, 20, 30...
   • Maximum Triangle Edge Length (meters) (default "30"): In the triangular network constructed from ground points, triangles with edge lengths greater than this threshold will not participate in contour generation. This will result in discontinuities in the contours where point cloud gaps exceed this threshold. To avoid such gaps, set this threshold larger than the maximum size of point cloud gaps.
   • Intermediate Contours (default selected): Also known as half-distance contours. When the primary contours do not display certain local features, intermediate contours are drawn at half the contour interval. If not needed, uncheck this option.
     • Contour Interval (meters) (default "2.5"): The height difference between adjacent intermediate contours.
     • Color (default yellow): The color of the intermediate contours, which can be modified.
     • Line Width (default "1"): The line width of the intermediate contours, which can be modified.
   • Primary Contours (default selected): Also known as basic contours. These are the main contours representing the topography, drawn according to the basic contour interval. If not needed, uncheck this option.
     • Contour Interval (meters) (default "5"): The height difference between adjacent primary contours.
     • Color (default blue): The color of the primary contours, which can be modified.
     • Line Width (default "2"): The line width of the primary contours, which can be modified.
   • Index Contours (default selected): Also known as bold contours. To facilitate height reading, index contours are drawn every four primary contours. If not needed, uncheck this option.
     • Contour Interval (meters) (default "25"): The height difference between adjacent index contours.
     • Color (default red): The color of the index contours, which can be modified.
     • Line Width (default "3"): The line width of the index contours, which can be modified.
   • Generate Elevation Annotation Points (default selected): Generate elevation points for terrain map output.
     • Radius (meters) (default "15"): Generates an elevation annotation point for a 15-meter radius area.
   • Optimization Options: Optimization settings for smoothing the generated contours.
     • Mean Smoothing (default selected): Smooths contours by replacing the current point with a weighted average of neighboring contour points.
       • 3: Number of neighboring contour points for smoothing.
         • 5 (default): Number of neighboring contour points for smoothing.
       • 7: Number of neighboring contour points for smoothing.
     • Bezier Smoothing (default "155"): A curve smoothing method with an angle threshold range of (0,180) degrees; a larger threshold results in smoother contours.
     • Delete Contours When Area < (m²) (default "25"): Delete closed contours with an area smaller than this value.
     • Delete Contours When Length < (meters) (default "5"): Delete open contours shorter than this value.
   • Default Values: Click this button to restore all parameters to default values.

3. After configuring the parameters, click OK to generate the contours and add them to the scene. To save to a file, click Save.

Generate Elevation Annotation Points

Generate elevation points for terrain map output based on the point cloud and contours.

1. Click the left mouse button to select a region, double-click to finish.

2. A parameter interface will appear. Set the point cloud and elevation point radius.

   
   • Input Point Cloud Data: Input file is a single point cloud data file.
   • Radius (meters) (default "15"): Generates an elevation annotation point for a 15-meter radius area.

3. Click OK to generate the elevation annotation points and add them to the scene. To save to a file, click Save.

Check Contour Consistency

If the current contour objects contain contour data and elevation points, contour conflicts can be detected. The results will be marked in the scene (red circles) and displayed in the right panel with detailed conflict information:

• Theoretical Value: Theoretical height values of conflicting points based on point cloud calculations.
• Actual Value: The actual height values of the conflicting points, i.e., the z-values of the current points (vector entities).
• Accept: Click to remove the circular marking in the scene.
• Delete: Delete the selected elevation annotation points.

Click on a row in the table to highlight the corresponding point in the scene, and double-click to center the point in the scene.

Accepting or deleting will not modify the file. To save changes, click Save. The circular or highlight effects will not be saved to the file.

Filter by Minimum Area

Filter out contour entities with an area smaller than a given value, marking them as selected in the scene.

• Layer: The layer to be used for filtering; layers not selected will not be processed.
• Minimum Area (m²): Filter out data with an area smaller than this value.

Only closed contours are considered; open contours are not processed.

Topological Check

Check for intersection errors in contour points in the scene and mark them as conflicts in both the table and the scene.