Regularize Building Footprint—Help

Summary
Illustration
Usage
Syntax
Code sample
Environments
Licensing information

Summary

Normalizes the footprint of building polygons by eliminating undesirable artifacts in their geometry.

Illustration

Usage

This tool utilizes a polyline compression algorithm to correct distortions in building footprint polygons created through feature extraction workflows that may produce undesirable artifacts.
The tolerance value defines the region surrounding the polygon's boundacry that the regularized polygon must fit into. This region can best be visualized by converting the polygon's boundary to a line feature, and then buffering the line by the desired tolerance distance.
If your building footprints contain circular structures, those features should be processed first. A compactness ratio can be used to identify circular buildings. To calculate this value, do the following:
1. Add a field of type double.
2. Use the field calculator to compute the following formula:
```
(4 * 3.14159265358979 * !shape.area!) / !shape.length! ^ 2
```
3. A perfect circle will have a value of 1, but since the polygons typically processed with this tool have some irregularity, values closer to 1 are more likely to have a circular shape. Evaluate your results to identify the minimum value of a circular building and select values greater than or equal to this value prior to executing this tool with the CIRCLE method.
When the specified parameters cannot produce a regularized solution for a given input, the original feature is copied to the output. The value specified in the STATUS field will indicate whether the feature was regularized or not:
- 0—Original feature
- 1—Regularized feature
Note:
If your output contains features that could not be regularized, consider iteratively running the tool by selecting the unprocessed features and altering the parameters to identify a solution. Background imagery can be very helpful for evaluating the accuracy of the regularized output.

Syntax

RegularizeBuildingFootprint_3d (in_features, out_feature_class, method, tolerance, densification, precision, diagonal_penalty, min_radius, max_radius)

Parameter	Explanation	Data Type
in_features	The polygons that represent the building footprints to be regularized.	Feature Layer
out_feature_class	The feature class that will be produced by this tool.	Feature Class
method	The regularization method to be used in processing the input features. RIGHT_ANGLES —Useful for building footprints that are primarily defined by right angles RIGHT_ANGLES_AND_DIAGONALS —Useful for buildings footprints that are comprised of right angles and diagonal sides ANY_ANGLE —Useful for buildings with highly irregular footprints CIRCLE —Useful for buildings with circular characteristics, like grain silos and water towers	String
tolerance	The maximum distance that the regularized footprint can deviate from the boundary of its originating feature. The specified value will be based on the linear units of the input feature's coordinate system.	Double
densification	The sampling interval that will be used to evaluate whether the regularized feature will be straight or bent. The densification must be equal to or less than the tolerance value. This parameter is only used with methods that support right angle identification.	Double
precision	The precision used by the spatial grid employed in the regularization process. Valid values range from 0.05 to 0.25.	Double
diagonal_penalty	Controls the distance bias for creating right-angle connections. Distances smaller than the diagonal penalty will be used to create right angles. This parameter is only used with the RIGHT_ANGLES_AND_DIAGONALS method.	Double
min_radius	The smallest radius that a regularized circle can have. A value of 0 implies there is no minimum size limit. This option is only available with the CIRCLE method.	Double
max_radius	The largest radius that a regularized circular can have. This option is only available with the Circle method.	Double

Code sample

RegularizeBuildingFootprint example 1 (Python window)

The following sample demonstrates the use of this tool in the Python window.

arcpy.env.workspace = 'c:/data'
arcpy.ddd.RegularizeBuildingFootprint('rough_footprints.shp', 
                                      'regularized_footprints.shp',
                                      method='Circle', tolerance=1.5, min_radius=10, 
                                      max_radius=20)

RegularizeBuildingFootprint example 2 (stand-alone script)

The following sample demonstrates the use of this tool in a stand-alone Python script.

'''****************************************************************************
       Name: Regularize Building Footprints
Description: Extract footprint from lidar points classified as buildings and 
             regularize its geometry.

****************************************************************************'''
import arcpy

lasd = arcpy.GetParameterAsText(0)
footprint = arcpy.GetParameterAsText(1)

try:
    lasd_layer = 'building points'
    arcpy.management.MakeLasDatasetLayer(lasd, lasd_layer, class_code=6)
    temp_raster = 'in_memory/bldg_raster'
    arcpy.management.LasPointStatsAsRaster(lasd_layer, temp_raster,
                                           'PREDOMINANT_CLASS', 'CELLSIZE', 2.5)
    temp_footprint = 'in_memory/footprint'
    arcpy.conversion.RasterToPolygon(temp_raster, temp_footprint)
    arcpy.ddd.RegularizeBuildingFootprint(temp_footprint, footprint, 
                                          method='RIGHT_ANGLES')


except arcpy.ExecuteError:
    print(arcpy.GetMessages())

Environments

Licensing information

ArcGIS Desktop Basic: Requires 3D Analyst
ArcGIS Desktop Standard: Requires 3D Analyst
ArcGIS Desktop Advanced: Requires 3D Analyst