The Andrew A. Humphreys monument stands near the center of Fredericksburg National Cemetery, located within the Fredericksburg and Spotsylvania National Military Park. It commemorates the charge Union General Andrew A. Humphreys led against the Confederate position along Marye’s Heights (upon which the cemetery is now located) during the Battle of Fredericksburg on December 13, 1862.
This model of the monument was created using Agisoft Metashape, a photogrammetric processing program. A total of 37 images, divided into two chunks, were used to generate a point cloud in Metashape. Photos were taken in a circular motion at two step intervals to obtain as much coverage of the monument as possible, and a stepladder was used to take pictures of the statue from a higher angle. By taking the photos at close intervals, the program was able to align the photos and identify tie points in the images to help mesh them together when creating the point cloud. Below are examples of the statue taken at even intervals.
From the point cloud, a dense cloud is generated, which fills in more tie points. Since the photos include background features such as trees and sky, the point cloud generated from the matching points in the images may contain extra data points. These can be deleted in order to clean up the background of the model. After deleting any extra points, the mesh is built, followed by the texture. The completed model can be viewed below.
This project was completed in the spring of 2021 for Associate Professor Michael Spencer’s HISP 345: Computer Applications in Historic Preservation class at the University of Mary Washington
