10 Aug Project Update: Carnegie Mansion Pergola
Fellow LHIPster Naomi Doddington and I collaborated on documenting a pergola structure located within the former mansion of famous Andrew Carnegie, now the Cooper Hewit Design Museum. The pergola is composed of four free standing limestone columns which support a three level wooden trellis with decorative rafter tails. The wooden structure has withstood weathering of over 100 years, and as you can imagine, it isn’t in tip-top shape. It will soon be replaced, this was one of the driving factors that lead HABS to obtain the contract with the Cooper Hewit Foundation. Earlier this summer we completed our fieldwork in New York lead by HABS Architects Robert Arzola and Paul Davidson. We completed a number of profile sketches, wood assembly sketches, laser scans, and photogrammetry photos. Below are some field photos and cornice profile sketches.
Back in the office I worked with Dan De Sousa on adjusting the point cloud model (featured below). Since the laser scanner completes a 360 degree sweep there is unnecessary information that needs to be erased from the model. Once the model is all cleaned up we can begin to produce our drawings. As you can seen from the images below, the machine scans with an exceptional amount of precision.
Although the precision of the laser scanner is stellar, there are issues when it comes to intricate details such as those found on the decorative wall. For this level of detail we take a series of photos in a number of orientations and perspectives which will give us the ability to use a process known as photogrammetry. A program stiches these photos together to create a 3-D model of the photographed object. From here we can frame orthogonal images of the photogrammetry model (similar to our point cloud model) to draw the complex details. Below are the orthogonal frames taken from the photogrammetry model. Below is a first draft of the Decorative Wall Elevation. All the required drawing have been completed and we are now working on sheet layouts. Stay tuned!