To generate terrain from a point cloud

After importing point cloud data, you can use that data to generate terrain and extract features in your model.

You must run point cloud terrain generation to process the data and extract features before using the Point Cloud Modeling tool.

1. Click Manage Point Clouds (Point Cloud Terrain).

2. Select the point cloud data set(s) you want to process.

3. Specify options for the level of detail used in processing the data for the terrain and features. For each of the following options, you can choose from the drop-down list. The default value is set to Optimum for all options. If you select Custom, additional options are available.

   Ground

   Classify ground surface points; less detail will be smoother.

   Custom Option	Description
   Ground Details	Adjust this value to set the resolution (grid size) for processing ground surface points from the point cloud data. Features larger than this value will be maintained in the surface. Units for this value are meters.
   Terrain Raster Resolution	The resolution of the terrain raster image created during the terrain generation process. This value indicates maximum row/column size of the output raster. With a setting of 2000, maximum terrain raster will be 2000 x 2000 pixels. The software also attempts to optimize this terrain raster size based on data density and extents. Units for this value is raster image size.
   Fill Terrain Holes	Holes in terrain data are filled with interpolated available data, creating a solid terrain surface. Switch this option off if you need to identify genuine holes in the data, such as water bodies or voids/shadows in the point cloud collection.
   Processing Window Size	Set the processing window size large enough to fit the largest object (for example, a building in the data set) to avoid the mistake of treating it (such as the building roof) as terrain. Units for this value are meters.

   Linear Feature

   Classify points representing road curbs, guardrails, and other line work. Aggressive processing will find more linear feature points (even faint ones in the data) than Optimum, and selecting Passive processing will find fewer points.

   Custom Option	Description
   Feature Resolution	Adjust this value to set the resolution (grid size) for processing linear features from the point cloud data. Linear features sized (usually width) smaller than this value might be skipped for this classification. Units for this value are meters.
   Min Allowable Intensity	Minimum intensity required to classify the points as a linear feature. Units for this value are the same as the intensity value (range is 0-255).
   Max Curb Height	Points above the Min Curb Height and below this height are considered part of the curb edge in a linear feature. Units for this value are meters.
   Min Curb Height	Points above this height and below the Max Curb Height are considered part of the curb edge in a linear feature. Units for this value are meters.

   Vertical Feature

   Classify points representing trees, streetlights, and signs.

   Custom Option	Description
   Min Points Per Object	Minimum number of points required to consider a group of points as a vertical feature.
   Feature Size	Distance between collections of points to classify the points as two vertical features. If the distance is less than this value, then the points are classified as a single vertical feature. Units for this value are meters.

4. Specify options for the processed data:

• Override Model Point Cloud: Disable this option if you want to be able to reprocess the original point cloud data later. If you deselect the option, the processed data is added to the ProcessedPointCloud proposal, which may increase model file size.
• Select Proposal for Processed Data: Accept the default or choose another proposal to save the processed data. This option is available if you did not select Override Model Point Cloud.
• Generate Data: Select the level of detail for the data. Selecting Lightweight or Keypoints may improve performance, but may also result in fewer ground points.
• Export Processed File: You can export the processed data as an RCS file for use in other applications. If you select to export the data, you also need to specify where to save the file.

5. Click Start Processing. A status message indicates the processing progress. If you click Cancel, the process is stopped and any data that has already been generated is saved. When the data is processed, the terrain displays in the model.