Simplify Building (Cartography)

Summary

Simplifies the boundary or footprint of building polygons while maintaining their essential shape and size.

Illustration

Usage

• The Minimum area parameter applies to simplified buildings only. Any buildings that are smaller than the minimum area after the simplification process is completed will be removed from the output feature class.

• The output feature class will include a field named BLD_STATUS to indicate simplification status as follows:

  • 1 = a single building has been simplified
  • 2 = a single building has been simplified to its minimum bounding rectangle
  • 3 = a building smaller than the tolerance squared has been simplified to its minimum bounding rectangle
  • 5 = a building that has not been simplified
  Legacy:

  Prior to ArcGIS version 10, BLD_STATUS = 4 indicated simplified or partially simplified buildings connected with straight lines. BLD_STATUS = 4 is no longer used.

  Caution:

  If a field named BLD_STATUS exists in the input feature class it will be present in the output feature class populated with new values. Existing values will be overwritten. If you want to preserve the existing values, create a new field on the input feature class and copy the existing values of the BLD_STATUS field to this new field.

• If the Check for spatial conflicts parameter is used, the tool will detect spatial conflicts and add a new field named SimBldFlag to the output to store conflict flags. A value of 0 means no conflict; a value of 1 means conflict.

  Caution:

  If a field named SimBldFlag exists in the input feature class it will be present in the output feature class populated with new values. Existing values will be overwritten even if this parameter is unchecked (NO_CHECK in Python). When spatial conflicts are not being checked, this existing field will be overwritten with NULL values. If you want to preserve the existing values, create a new field on the input feature class, and copy the existing values of the SimBldFlag field to this new field.

• This tool cannot be executed within an edit session.

• Input Z values can be preserved if specified in the Environment Settings. Where output vertices are coincident to input feature vertices, Z values will be transferred to output vertices. Elsewhere, Z values will be derived either from existing Z values or through interpolation.

• Invalid (self-intersecting) geometry may be created during the simplification process and will be repaired but not improved. For example, if a polygon crosses itself, the polygon will become a multiple-part polygon but will still look self-crossing.

Syntax

SimplifyBuilding_cartography (in_features, out_feature_class, simplification_tolerance, {minimum_area}, {conflict_option})

Parameter	Explanation	Data Type
in_features	The building polygons to be simplified.	Feature Layer
out_feature_class	The output feature class to be created.	Feature Class
simplification_tolerance	Sets the tolerance for building simplification. A tolerance must be specified, and it must be greater than zero. You can choose a preferred unit; the default is the feature unit.	Linear unit
minimum_area (Optional)	Sets the minimum area for a simplified building to be retained in feature units. The default value is zero, that is, to keep all buildings. You can specify a preferred unit; the default is the feature unit.	Areal unit
conflict_option (Optional)	Specifies whether or not to check for potential conflicts, that is, overlapping or touching, among buildings. A field named SimBldFlag is added to the output to store conflict flags. A value of 0 means no conflict; a value of 1 means conflict. NO_CHECK —Specifies not to check for potential conflicts; the resulting buildings may overlap. This is the default. CHECK_CONFLICTS —Specifies to check for potential conflicts; the conflicting buildings will be flagged.	Boolean

Code Sample

SimplifyBuilding example 1 (Python window)

The following Python window script demonstrates how to use the SimplifyBuilding function in immediate mode.

import arcpy
from arcpy import env
import arcpy.cartography as CA
env.workspace = "C:/data"
CA.SimplifyBuilding("buildings.shp", "C:/output/output.gdb/simplified_buildings", 10)

SimplifyBuilding example 2 (stand-alone script)

The following stand-alone script demonstrates how to use the SimplifyBuilding function.

# Name: SimplifyBuilding_Example2.py
# Description: Aggregate building features and then simplify them
 
# Import system modules
import arcpy
from arcpy import env
import arcpy.cartography as CA
  
# Set environment settings
env.workspace = "C:/data/Portland.gdb/Buildings"
 
# Set local variables
inBuildingFeatures = "houses"
aggregatedFeatures = "C:/data/PortlandOutput.gdb/residential_areas"
simplifiedFeatures = "C:/data/PortlandOutput.gdb/residential_simplified"

# Aggregate house polygons.
CA.AggregatePolygons(inBuildingFeatures, aggregatedFeatures, 10, 100, 100, "ORTHOGONAL")
 
# Simplify residential building polygons.
CA.SimplifyBuilding(aggregatedFeatures, simplifiedFeatures, 10, 100, CHECK_CONFLICTS)

Environments

Current Workspace, Default Output Z Value, Output M Domain, Output XY Domain, Output Coordinate System, Extent, Output has M values, Output has Z values, Scratch Workspace, XY Tolerance

Licensing Information

ArcGIS for Desktop Basic: No

ArcGIS for Desktop Standard: No

ArcGIS for Desktop Advanced: Yes