3D Visualization of Sweet Briar House

Transcription

1 SWEET BRIAR COLLEGE 3D Visualization of Sweet Briar House 2013 Honors Summer Research Li Fumin 7/19/2013

2 1 Abstract The purpose of this research was to generate a 3D model of Sweet Briar House (the House) using AutoCAD, a software application for computer-aided design and drafting. The House has been home to the presidents of Sweet Briar College since 1901 and it is listed on the National Register of Historic Places. A new model of the house is much needed since the existing plans of the house are not reflective the real structure of the house and also lack of sufficient dimensions. The model of the house was created and visualized based on existing plans and ultrasonic tape measurement was used as a supplementary tool to size the architectural details of the house. After all the measurements were finished, the full 3D reconstruction of the house was performed in AutoCAD. The ultimate goal for this research is to create a visual reality model for Sweet Briar House so that people can visit this historical building online. Page 1 of 13

3 2 Table of Contents Abstract... 1 Table of Contents... 2 List of Figures... 2 Introduction... 3 Sweet Briar House... 3 Computer Aided Design... 5 Methodology... 5 Results... 8 Conclusion Acknowledgements...12 References List of Figures Figure 1. Drawing of Sweet Briar House from circa 1790s 3 Figure 2. Boxwood Gardens and Sweet Briar House Grounds...4 Figure 3. Interior of Sweet Briar House, circa 1920s Figure 4. 3D Modeling Mode in AutoCAD 6 Figure 5: Generating geometry 6 Figure 6. The Front View of the House from the 1927 Plan...7 Figure 7. First Floor Plan in 2D..8 Figure 8. Second Floor Plan in 2D..9 Figure 9. Third Floor Plan in 2D.9 Figure 10. First Floor Plan in 3D Figure 11. Second Floor Plan in 3D.10 Figure 12. Third Floor Plan in 3D Figure 13. Entire Model of the House in 3D Page 2 of 13

4 3 Introduction Sweet Briar House Originally a six-room, T-shaped farmhouse, Locust Ridge was first built by the Crews family in the late eighteenth century (Figure 1). In 1830, Elijah Fletcher, a New England school teacher, bought the House at a public auction and changed the name of the property to Sweet Briar. In 1846, the Fletcher family made Sweet Briar House their permanent home. Figure 1. Drawing of Sweet Briar House from circa1790s The enlargement of the house started in the spring of During the construction, two tower wings and a connecting arcaded portico were added to the original house (Figure 2). Largely adopting Italian Villa style, the new house reflected the family s strong interests in Italianate architecture which was fostered during a grand tour of Europe. Most of the furniture in the house was bought in New York and Philadelphia. After the death of Daisy, the granddaughter of Elijah Fletcher, Indiana (Fletcher) and James Henry Williams planned to establish a school for girls in her memory on the grounds of the plantation. The first president of the college, Mary K. Benedict, used the House as her residence. It also contained faculty residences, the post office, the infirmary, and administration offices until 1926 (Figure 3). A sign for the post office can still be seen in the House's basement. A 1927 fire damaged the central part of the house and led to the rebuilding and modernization of the central part and east wing of the house. The House is now registered as one of the National Register of Historic Places and is still the residence of the presidents of Sweet Briar College. Page 3 of 13

5 4 Figure 2. Boxwood Gardens and Sweet Briar House Grounds Figure 3. Interior of Sweet Briar House, circa 1920s Page 4 of 13

6 5 Computer Aided Design Computer aided design (CAD) techniques assist in the creation, modification, analysis, or optimization of a design and are widely used by many fields such as electronic, mechanical, and structural design. CAD can be used for curves and figures in two-dimensional (2D) space or curves, surfaces, and solids in three-dimensional (3D) space. For this project, both functions in 2D and 3D are used. The house was reconstructed using AutoCAD Unlike traditional hand sketches, CAD provides great efficiency and accuracy for engineers to create design. First of all, generating 2D and 3D models, computer-aided technique allows the sketches to be rotated in all dimensions. This offers a great amount of details so that anyone can visualize the product easily. Also, drawing with computers avoids some of human error which often happens when manually drawing by hands. This not only offers accuracy, but also saves time and money. In addition, one of the most useful functions in CAD is the layer. Users can create many different layers of the sketch with each of the layers contain different systems, such as one layer for exterior walls, one for water pipes, etc.. The combination of all the layers will be the final drawing. With this function, it is much more convenience for the user to sketch since fixing one layer will not result in messing up the other, which often happens when sketching by hand. Lastly, there are four properties often used which are history, features, parameterization, and high level constraints. The construction history can be used to look back into the model's personal features and work on the single area rather than the whole model. Parameters and constraints can be used to determine the size, shape, and other properties of the different modeling elements. The features in the CAD system can be used for the variety of tools for measurement such as tensile strength, yield strength, electrical or electro-magnetic properties, also its stress, strain, timing or how the element gets affected in certain temperatures, etc. Methodology The goal of this project was to reconstruct the House with the help of AutoCAD 2013, supplemented by blueprints of the building as well as the ultrasonic tape measurement. This computer aided design (CAD) program published by Autodesk was developed to manage the complex factors involved in site planning. The basic method to develop 3D images in AutoCAD starts with drawing the shape in 2D. For example, to draw a simple box in 3D, a rectangle should be first drawn in 2D using rectangle drawing tool. Then, change the mode to 3D Modeling (Figure 4) to start extruding the 3D box. Under the 3D Modeling mode, use modeling tool, presspull, to extrude the existing 2D rectangle to get the desired box. Page 5 of 13

7 6 Figure 4. 3D Modeling Mode in AutoCAD The process of the CAD reconstruction was broken into four parts. The process started by defining the boundaries of the project site. The primarily boundaries of the House were defined largely based on existing plans supplied by Sweet Briar College's Physical Plant from the 1927 post-fire reconstruction and the non-dimensioned plans from the 1990s. After the boundary was set, the site and construction modules prompted the user to define site objects and construction objects. Default objects were contained in the AutoCAD database, whereas, most of the time, modifications of the objects were needed to meet the user s objective. The properties of an object were classified into two catalogs geometric properties, such as size, and non-geometric properties, such as textures or materials. In addition, there is also a chance that the objects required in the project were not defined in the database and there are no similar objects that the user can modify to get the desired object. This was the case for this project, so new objects were created by initially defining the geometry of the object. Generally, there were three ways to generate geometries (Figure 5). All of the methods lead to successful geometry generation. For this project, the 'draw in CAD' method was used, since the project was done in the AutoCAD environment. The other two methods were still be taken into consideration as supplements. Figure 5: Generating geometry As all the desired objects were modified and created, the constraints of the construction objects were defined. Since every object was related to the others in a Page 6 of 13

8 7 certain way, it was important to realize and list the number of constraints of each object and understand how the objects were related to each other. The following construction queuing stage was dependent largely on this step. The last step to take was the construction objects queuing. Since each object was added individually, the order in which construction objects were located on site affects the final layout. Each of the construction objects was ranked based on its correlation with the other objects. Once the queuing is evaluated, objects were generated one by one, following the priorities ranked. The basic dimensions of the house were obtains from two existing plans. The first plan referenced was first created in 1927 after the fire. Figure 6. The Front View of the House from the 1927 Plan Blueprints from 1927 were provided by Sweet Briar's Physical Plant. The plans had specific 1:4 dimensions and the front columns and the portico were shown with details. Therefore, some degree of architectural details could be obtained, but since the plan was finished in 1927, some of the House's details were not accurate or missing (Figure 6). Moreover, the back and side views were not provided.. The other plans used for this project were finished in 1990s and were more up-to-date, but failed to include any efficient scale; therefore it was hard to rely on dimensions from this plan. Furthermore, though this plan showed a more recent view of the house, some newly added closets were not included. Page 7 of 13

9 8 Neither of the plans was perfect due to inconsistencies between the plans and the House of today. There were also, no dimensions on 1990s plans and no dimensions of architectural details, such as ceiling heights, floor thickness, molding, or door casings. Therefore, extensive measurements of the interior of the House were performed and the dimensions and layout shown on existing plans were confirmed. A tape measure and ultrasonic laser distance measurer were used to obtain the needed dimensions. Interviews with Sweet Briar personnel for stories and information about the history of the house were also conducted. Results As mentioned above, the reconstruction of the House in 3D started with plotting each floors in 2D. For the each floor, different colors represent portions of the house built at different times and drawn in different layers, or construction object queues (Figure 7). For example, the red layer contains the oldest walls built in the late eighteenth century, and the green layer contains the newer walls built in the 1850s during the enlargement. Stairs are shown in yellow, porches in white, and fireplace aprons in purple. Similar plots were developed for the second and third floor as well (Figures 8 and 9). Figure 7. First Floor Plan in 2D Page 8 of 13

10 9 Figure 8. Second Floor Plan in 2D Figure 9. Third Floor Plan in 2D Several issues took place during the process of extruding 2D plot into 3D. The computer power required for this phase was beyond the capacity of the computer used for this project and the AutoCAD application constantly stopped responding, resulting in the loss of every unsaved modification in the file. Another issue was file corruption, which happened after a damaged file was saved. The result of this issue was that the whole file could never be opened by any application and resulted in losing everything in the file. Because of the file corruption, some parts of the 3D first floor plan were lost and could not be recovered (Figure 10). The 3D drawing of the second floor is more complete (Figure 11). Page 9 of 13

11 10 Figure 10. First Floor Plan in 3D Figure 11. Second Floor Plan in 3D The drawing of the third floor contains a representation of the roof lines in addition to the rooms (Figure 12). The reconstruction of the roof part was the most complicated part of this project because of the lack of sufficient views of the roof in the existing plans. The only reference of the roof was a 2D plot and visual and physical access to the roof were very difficult. Many of the roof's dimensions are therefore approximate. Page 10 of 13

12 11 Figure 12. Third Floor Plan in 3D The entire model of the house in 3D (figure 13) was generated using the insert function in AutoCAD. The function pulled out the models from multiply files and allowed the user to move and combine the models. When placing the 3D models of each floor together, an inconsistency between the third and the second floor was noticed. The west wall of the east tower wing was slightly thicker than the walls at the same place on the other floors. Checked both planes used for this project, this inconsistency was not caused by human error from this project. The reason might be the measurement error from the previous plans. Figure 13. Entire Model of the House in 3D Conclusion Doing this project, I realized that the existing plans of Sweet Briar house do not provide enough details. The new model from this project may provide a more Page 11 of 13

13 12 accurate plan for further construction of the house. I would like to continue doing this project by adding more physical details, such as the columns, the molding and the wall colors. As the model becomes more detailed, it may be used for marketing promotion for the college. This project also provided me with a lot of experience in AutoCAD, which most of the companies in the structural engineering field require. This opportunity provided a hands-on experience of visualizing buildings. Furthermore, I realized that rendering historic buildings in 3D could face many problems. O ne of them could be that the original blueprints are hard to obtain or lack of accuracy. This may requires intensive labor to get into the building to get measurements, but becomes hard or impossible if part of the building is damaged or does not exist anymore. Acknowledgements I would like to acknowledge President Parker and Mr. Manasa for allowing me unlimited access to the House for measurements. I would especially like to thank Ms. Trout, the housekeeper, who provided me with stories about the house and a very detailed tour into the basement of the house to obtain floor height measurements. Thanks are also due to Physical Plant for providing the existing plans of the House and the Honors Committee for sponsoring my research. References Flickr. (14 July 2013; Moody, Jr., J. R National Register of Historic Places Inventory-Nomination Form. Oursource 3D Modeling. (14 July 2013; ) Pbworks The Administration Building, Sweet Briar College. (14 July 2013; rdens) Sweet Briar College Museum Sweet Briar House (14 July 2013; Tumblr. (14 July 2013; briarhistory.tumblr.com) Tusculum Institute A painting of Locust Ridge, circa 1790s. (14 July 2013; Farnaz Sadeghpour, Osama Moselhi, Sabah Alkass. Open Architecture for Site Layout Modeling. Quebec, Canada: Department of Building, Civil and Environmental Engineering, Concordia University, n.d. Page 12 of 13

14 13 Sadeghpour, F., Moselhi, O., and Alkass, S Computer-Aided Site Layout Planning. J. Constr. Eng. Manage., 132(2), Th. Kersten, C. Acevedo Pardo, M. Lindstaedt. 3D Acquisition, Modelling and Visualization of North German Castles by Digital Architectural Photogrammetry. ISPRS WG V/s Scene Modelling and Virtual Reality (n.d.). Page 13 of 13