Creating Island Breaklines in LP360

The following workflow and accompanying video describes the suggested workflow for digitizing breaklines around islands within LP360.

Creating Island Breaklines: Workflow

  1. Configure a conflation task for the lake or main waterbody that the island resides within.
    1. Set up a conflation method for the conflation task
      1. This is dependent upon user specifications, the example in the video chooses to use one specific value for the feature as a whole (in this instance the min z value is being assigned and is stored in the attribute table). Typically one would use the points contained within the feature.
    2. Specify a Type Field (HType) and specify the name depending on the type of waterbody (i.e Lake, Pond, Ocean, River)
      1. The idea behind using an HType field is to give the user the ability to distinguish between different features within the same feature class
  2. Configure a conflation task for the islands
    1. Set a conflation method
      1. This is dependent upon user specifications, the example in the video chooses to use one specific value for each vertex, but doesn’t really matter as the values will be overridden by the digitize process that will be used.
    2. Specify a Type Field (HType) and set the attribute as Island.
  3. Create a shapefile to use during the digitization process
    1. Make sure the file is 3D Enabled
    2. Add a text field to the attribute table called HType
      1. Set the length of the text field to 25
    3. Add a double field to the attribute table called MinZ Field
      1. Set a precision of 11 and a scale of 4
  4. Digitize the main waterbody going in a clockwise direction
    1. Click the P key on the keyboard to active the profile window when digitizing within LP360 for ArcMap
    2. Draw a profile prior to digitizing within LP360 for Windows to view the profile while digitizing
  5. Digitize the islands going in the counterclockwise direction
    1. In this instance digitization direction is very important
  6. Add a new Point Cloud Task that will reclassify any ground points that are located within the main waterbody, reclassify any water points that are on the island back to ground points and then reclassify around the breaklines into a breakline proximity class
    1. Task Type: Macro
    2. Task Name: Island Reclassification
  7. Add a new task to the Macro
    1. Task Type: Classify by Feature
    2. Task Name: Classify Water
    3. Feature Geometry Layer: Newly created digitized shapefile
    4. Source Points: Ground Only
    5. Fields: HType
      1. Uncheck Island
      2. Check Lake and specify completely within to class 9 – Water
  8. Add a new task to the Macro
    1. Task Type: Classify by Feature
    2. Task Name: Classify Island
    3. Feature Geometry Layer: Newly created digitized shapefile
    4. Source Points: Water Only
    5. Fields: HType
      1. Check Island and specify completely within to class 2 – Ground
      2. Uncheck Lake
  9. Add a new task to the Macro
    1. Task Type: Classify by Feature
    2. Task Name: Classify Breakline Proximity
    3. Feature Geometry Layer: Newly created digitized shapefile
    4. Source Points: Ground Only
    5. Specify within a distance.
      1. Distance should be at least equal to the Nominal Pulse Spacing of the dataset
      2. Reclassify data to class 12 – Excluded Ground (Breakline Proximity) as per the revision in the USGS LBS v1.3. Formally they were using class 10.
  10. Activate Breakline Enforcement for the waterbodies and the islands
  11. Display the data using the TIN and turn on the contours, make sure the data is at 100% in order for breakline enforcement to work

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