Create a 2D footprint of a 3D multipatch feature at a certain elevation in ArcGIS Pro

Summary

A multipatch feature stores multiple patches representing the boundaries of a 3D object and is commonly used to portray and project buildings in ArcGIS Pro scenes. At times, it may be necessary to retrieve the 2D footprint of a 3D multipatch feature at a certain height or elevation for analysis purposes. For instance, this can be useful to outline the floor plan of a building, which can differ on different floors, elevations, or heights.

This article provides the steps to create a 2D footprint at a certain elevation of a 3D multipatch feature in ArcGIS Pro by creating a new thin multipatch feature, and using the Intersect 3D and Multipatch Footprint tools.

Procedure

1. Open the project with the 3D multipatch feature in ArcGIS Pro.
2. Create a new multipatch feature class.
   1. In the Catalog pane, right-click the database and click New > Feature Class.
   2. In the Create Feature Class pane, specify a name for the multipatch feature class.
   3. For Feature Class Type, click the drop-down menu and select Multipatch. Click Finish. In this example, the 'CrossSection' multipatch feature class is created.

4. On the Edit tab, in the Features group, click Create.
5. In the Create Features pane, under Templates, click the newly created multipatch feature class template.
6. In an aerial view, create a thin multipatch feature with a perimeter covering all boundaries or patches of the desired buildings. In this example, a thin multipatch is created to intersect two buildings. Refer to ArcGIS Pro: Create multipatch or 3D Object features for more information.
7. Set the new multipatch feature at a preferred elevation. Refer to ArcGIS Pro: Move, rotate, or scale a feature to move or scale the multipatch feature.

3. On the Analysis tab, in the Geoprocessing group, click Tools to open the Geoprocessing pane.
4. In the Geoprocessing pane, search for and select the Intersect 3D (3D Analyst Tools) tool.

5. Use the Intersect 3D tool to create an intersection of the newly created multipatch feature with the 3D multipatch building. In the Intersect 3D pane, under Parameters, configure the parameters as follows:
   1. For Input Multipatch Features, click the drop-down menu and select the newly created multipatch feature. In this example, 'CrossSection' is selected.
   2. For Input Multipatch Features, click the drop-down menu and select the 3D multipatch feature. In this example, 'StarBuilding' is selected.
   3. For Output Feature Class, the name is auto-filled. Alternatively, specify a name for the output feature class.
   4. For Output Geometry Type, click the drop down and select Solid.
   5. Click Run.

Note: 
Running the Intersect 3D tool with the Output Geometry Type parameter set to Solid for a non-closed multipatch feature returns warning messages, and no intersect result is generated. Alternatively, set the Output Geometry Type to Line. This setting, however, returns a 3D lines for the multipatch feature.

6. On the Analysis tab, in the Geoprocessing group, click Tools to open the Geoprocessing pane.
7. In the Geoprocessing pane, search for and select the Multipatch Footprint (3D Analyst Tools) tool.

8. Use the Multipatch Footprint tool to create the 2D polygon footprint for the intersection created in Step 5. In the Multipatch Footprint pane, under Parameters, configure the parameters as follows:
   1. For Input Feature Class, click the drop-down menu and select the output created in Step 5. In this example, 'CrossSection_Intersect3D3' is selected.
   2. For Output Feature Class, the name is auto-filled. Alternatively, specify a name for the output feature class.
   3. Click Run.

The image below shows the 2D polygon footprint at the preferred elevation of the 3D building multipatch feature.