Classify LAS Building (3D Analyst)

ArcGIS Pro 3.4 | | Help archive

Summary

Classifies buildings in LAS format point cloud data.

Illustration

Classify LAS Building tool illustration

Usage

  • Points with class code values of 0, 1, and 6 will be evaluated to determine if they fit the characteristics of building rooftops. Existing building classified points that do not satisfy the detection criteria will be reassigned to 1 unless the option to reuse existing building classified points has been set.

  • This tool was designed with an emphasis on aerial lidar, which usually captures building rooftops. Points representing walls, vertical facades, and small rooftop features—such as dormers and chimneys—may not be included in the building classification. If such points are necessary, consider running the tool with the options for classifying points that are above and below the roof.

  • Classify ground points before running this tool. If ground points have not been classified, use the Classify LAS Ground tool. If ground points are classified but they use a class code value other than 2, use the Change LAS Class Codes tool to reassign them accordingly.

  • The Method parameter is not used when the Is photogrammetric data parameter is checked.

Parameters

LabelExplanationData Type
Input LAS Dataset

The LAS dataset that will be classified.

LAS Dataset Layer
Minimum Rooftop Height
(Optional)

The height from the ground that defines the lowest point from which rooftop points will be identified.

Linear Unit
Minimum Area

The smallest area of the building rooftop.

Areal Unit
Compute statistics
(Optional)

Specifies whether statistics will be computed for the .las files referenced by the LAS dataset. Computing statistics provides a spatial index for each .las file, which improves analysis and display performance. Statistics also enhance the filtering and symbology experience by limiting the display of LAS attributes, such as classification codes and return information, to values that are present in the .las file.

  • Checked—Statistics will be computed. This is the default.
  • Unchecked—Statistics will not be computed.
Boolean
Processing Extent
(Optional)

The extent of the data that will be evaluated.

  • Current Display Extent Map View—The extent will be based on the active map or scene.
  • Draw Extent Square and Finish—The extent will be based on a rectangle drawn on the map or scene.
  • Extent of a Layer Layer—The extent will be based on an active map layer. Choose an available layer or use the Extent of data in all layers option. Each map layer has the following options:

    • All Features Select All—The extent of all features.
    • Selected Features Area from Selected Features—The extent of the selected features.
    • Visible Features Extent Indicator—The extent of visible features.

  • Browse Browse—The extent will be based on a dataset.
  • Intersection of Inputs Intersect—The extent will be the intersecting extent of all inputs.
  • Union of Inputs Union—The extent will be the combined extent of all inputs.
  • Clipboard Paste—The extent can be copied to and from the clipboard.
    • Copy Extent Copy—Copies the extent and coordinate system to the clipboard.
    • Paste Extent Paste—Pastes the extent and coordinate system from the clipboard. If the clipboard does not include a coordinate system, the extent will use the map’s coordinate system.
  • Reset Extent Reset—The extent will be reset to the default value.

When coordinates are manually provided, the coordinates must be numeric values and in the active map's coordinate system. The map may use different display units than the provided coordinates. Use a negative value sign for south and west coordinates.

Extent
Processing Boundary

The polygon feature or features that will define the area to be processed.

Feature Layer
Process entire LAS files that intersect extent
(Optional)

Specifies how the area of interest will be used in determining how .las files will be processed. The area of interest is defined by the Processing Extent parameter value, the Processing Boundary parameter value, or a combination of both.

  • Unchecked—Only LAS points that intersect the area of interest will be processed. This is the default.
  • Checked—If any portion of a .las file intersects the area of interest, all the points in that file, including those outside the area of interest, will be processed.
Boolean
Average Point Spacing

The average spacing of LAS points. This parameter is no longer used.

Linear Unit
Reuse existing building classified points
(Optional)

Specifies whether the existing building classified points will be reused or reevaluated.

  • Unchecked—Existing building classified points will be reevaluated to fit the criteria for plane detection, and points that do not fit the specified area and height will be assigned a value of 1. This is the default.
  • Checked—Existing building classified points will contribute to the plane detection process but will not be reclassified in the event they do not meet the criteria specified by the tool. Use this option if the existing classification is necessary.
Boolean
Is photogrammetric data
(Optional)

Specifies whether the points in the .las file were derived using a photogrammetric technique.

  • Unchecked—The points in the .las file were obtained from a lidar survey, not from a photogrammetric technique for producing point clouds. This is the default.
  • Checked—The points in the .las file were obtained using a photogrammetric technique for producing point clouds from overlapping imagery.
Boolean
Classification Method
(Optional)

Specifies the classification method that will be used.

  • AggressivePoints that fit the planar rooftop characteristics with a relatively high tolerance for outliers will be detected. Use this method if the points are not well calibrated.
  • StandardPoints that fit the planar rooftop characteristics with a relatively moderate tolerance for irregular points will be detected. This is the default
  • ConservativePoints that fit the planar rooftop characteristics with a relatively low tolerance for irregular points will be detected. Use this method if the building points are co-planar with points from objects that are not buildings.
String
Classify points above the roof
(Optional)

Specifies whether points above the planes detected for the roof will be classified.

  • Unchecked—Points detected above the planes will not be classified. This is the default.
  • Checked—Points detected above the planes will be classified.
Boolean
Maximum Height Above Roof
(Optional)

The maximum height of the points above the building rooftop that will be classified using the Above Roof Class Code parameter value.

Linear Unit
Above Roof Class Code
(Optional)

The class code that will be assigned to points above the roof.

Long
Classify points below the roof
(Optional)

Specifies whether points between the roof and the ground will be classified.

  • Unchecked—Points between the roof and the ground will not be classified. This is the default.
  • Checked—Points between the roof and the ground will be classified.
Boolean
Below Roof Class Code
(Optional)

The class code that will be assigned to points between the ground and the roof.

Long
Update pyramid
(Optional)

Specifies whether the LAS dataset pyramid will be updated after the class codes are modified.

  • Checked—The LAS dataset pyramid will be updated. This is the default.
  • Unchecked—The LAS dataset pyramid will not be updated.
Boolean

Derived Output

LabelExplanationData Type
Derived LAS Dataset

The LAS dataset that is classified for building rooftops.

LAS Dataset Layer

Licensing information

  • Basic: Requires 3D Analyst
  • Standard: Requires 3D Analyst
  • Advanced: Requires 3D Analyst

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