Track 4: This New World: Preservation technology and emerging issues within our historic buildings and built landscapes
APT Student Scholar Abstract
Preservation Through Digitization: Using Photogrammetry as a Tool for Replicating Building Components
Monday, September 24
10:30 AM - 12:00 PM
Jonathan Spodek, FAIA, FAPT – Ball State University
The accurate and thorough documentation of historic environments is critical to the success of any preservation project. Through emerging technologies, traditional means of documentation are now being supplemented with digital representations. Photogrammetry as a tool to document existing buildings has a long history of creating scalable documents from photographs. Recent advances present growing opportunities to create scalable 3-D models of existing sites and integrating these model into the fabrication process.
The growing accuracy of photogrammetry software is allowing for new applications of these models, including the replication of architectural components. Digital photographs combined with photogrammetric applications provide opportunities to document existing building components quickly and easily to generate 3-D models. These photogrammetric programs (i.e. ReCAP or Agisoft Photoscan) manage the process to create 3-D textured mesh models (image registration, object matching, photo-stitching, mesh generation) making 3-dimensional photogrammetry accessible and cost-effective. Models can be refined using surface modeling software (i.e. Maya, Fusion360, Rhino) creating scalable digital models for building documentation, virtual environments creation, or building component replication.
This methodology and application is presented through a case study project that documented and replicated a Louis Sullivan terra cotta cornice piece salvaged from the 1894 Chicago Stock Exchange building. The goal of this project was twofold. First was the creation of a digital model of the terra cotta component that could then be integrated into building modeling software (i.e. Revit). Second was to fabricate a physical replication of the same architectural piece using CNC routing technology. Each output goal was achieved by using the same initial photogrammetric mesh model, but the post-processing edits required different approaches, software, and output methods.
Digital images combined with accessible photogrammetric applications provide opportunities to document buildings quickly, easily, and without expensive equipment or extensive post-capture processing. Buildings and objects can be captured in-situ or in a lab/studio environment. This approach allows for the integration of 3D photogrammetry into professional work whether it is a traditional practice, a preservation focused business, or research-oriented work.
- Explain the methodology of digital photogrammetry and determine its application in preservation practice.
- Identify the advantages and limitations of digital photogrammetry in comparison to other methods of 3D reality capture such as 360-photos and laser scanning.
- Describe various applications of 3D documentation to replicate existing buildings and their components for documentation and replication through fabrication.
- Clarify the role of various software programs in the photogrammetric process and their potential products.