Virtual Design Analysis Group is a division of NVentum, LLC.


-CAPTURING HISTORY-
This unique collaborative endeavor; to utilize the latest reality capture technology to document the artifacts, buildings and campus of History San Jose, provides opportunities for private sector, non-profits and institutions of higher education to work together to solve some of today's most pressing engineering issues. The protocol for retrofitting as-built historic facilities and the use of new technologies to preserve our most prized historic treasures are vital to the continued success and expanded influence of our museums.
This blog will document the challenges and successes of this ambitious, one of a kind project.

Wednesday, January 14, 2015

The Kelley House
...Let's Talk About The Project
The opportunity to document such an iconic San Jose home was one we had been looking forward to for quite some time. Knowing the home was scheduled to be demolished added a level of urgency and a unusual sense of concern. There are no mulligans, no "do-overs"; the process has to be thorough, detailed and correct the first time. With many projects, you can take data back to the office for processing. If you happen to find that rare error, you can go back and re-scan the area in question and correct the problem. This is not one of "those" projects; the Kelley House has been scheduled for demolition. 

Some may wonder what is the value of laser scanning a building that has been totally destroyed by fire and water damage. What can we learn from the scans? What can be done with the data collected and why is this important?

Though the structure is a total loss, there is a lot of information that can be retrieved from laser scans. For example, the fire exposed the inner walls and ceilings and several areas of the home. The construction materials and methods used at the turn of the century, when the home was constructed are clearly visible. The exterior and interior walls of the home are heavily damaged but still intact. Laser scanning the building will give us the first millimeter accurate floor plan of the 100 year old historic home. 
From a forensic investigation perspective, a detailed point cloud of the home would allow investigators to trace and document the origins of the fire. These are a few of the things we can learn from the laser scanning process.
Beautiful Crown Molding
In the Library
In addition to extracting information from the point cloud, the user(s) can add/store information about the home within the point cloud using BIM software. Everything from notes about the type of materials and methods used to construct the custom bookshelves to details about the craftsmen that built the home's custom solarium can be downloaded into the software. This can provide a wealth of information for researchers, students or for anyone interested in the reconstruction of the home.
Now that the data has been collected, what do we do with it? I mentioned we could use BIM software and download a bunch of information about the building into the point cloud. 
We can model the existing data we've gathered.
We can also virtually reconstruct the house using a combination of the laser scans  historic photos. 
We can use the data collected to create training curriculum for the RCTTC. (..and we will!)
We can build an exhibit for the Preservation Action Council, Kelley Park and History San Jose.
Anything is possible, but first we must capture the data. 

It's critical that we capture the data as accurately and quickly as possible. For this reason, I decided to utilize both the FARO 3D Focus Laser Scanner and the trusty Z&F 6000 scanner to capture and document the home. Redundancy is a good thing... One of the challenges of this
project was capturing colorized laser scans of the property. The home was/is surrounded by dense, heavy foliage that creates lots of shadows and limits lighting both inside and outside of the home. For those who are familiar with laser scanning understand that while the laser requires no light at all, creating colorized laser scans involves the use of cameras. Of course, cameras do require light to capture detail and this is where the challenges begin. In addition to the heavy foliage, power to the house was destroyed during the fire. I didn't bring a generator therefore artificial light sources were not a viable option. The only thing I could do is rely on the FARO scanner settings to adjust for lighting deficiencies; not the best option but the most reasonable given the circumstances. The other "quick fix" would be to eliminate the colorized scans completely, therefore nullifying the lighting concerns. I decided to document the home and attempt to capture colorized scans of the the interior and exterior. 

I started by scanning the exterior of the home on the first day. Due to the heavy foliage and abundant shade, I set the scanner for an "Outdoor Cloudy" setting. Several times during the
scanning process, FARO's built in camera had trouble with the heavy shade and intermittent but very bright sunlight coming through the trees. At one point, I considered not using the camera at all. Not using the camera would eliminate the lighting issues, save power and save time. However, for reasons of consistency, I decided to continue to use the camera for all the scans. After all, you can never have too much data. If the quality of the colorized scans is not up to par, we can always discard the photos and still have an extremely accurate historic record of the home.
Kelley House Library

Day three of the project brought us inside the home for to begin scanning the second floor. This was one of the more nerve racking parts of the entire job. The area was hazardous to put things politely. The damage from the fire was extensive and had been exposed to the elements for 34 months. The near "monsoon" rains we had a couple of weeks earlier didn't help matters much. There were areas of the floor where you could see from the second floor clear through to the basement. I was not only focused on the job, I was also ever aware that each step I took had the potential to send me through the floor and possibly through to the concrete basement below. The hazards of a collapsed, fire damaged roof and floor were not the only things to look out for. The abandoned home had become a haven for all types of critters, big and small. In three days of scanning, I saw a fox run from the basement, I saw a raccoon on the
Second Floor Landing
back porch and the smell of highly irritable skunk was evident each morning and afternoon. So, as you were watching your step to avoid falling through the floor, you were also watching to avoid putting you foot or your tripod in a pile of "critter scat". Under these conditions is where the FARO 3D Focus laser Scanner really shines. The light weight, compact size made it the ideal tool for working in such a restrictive environment. Using any other scanner under these circumstances would have been a MAJOR undertaking.

 Day four was the beginning of the documentation of the first floor of the house. For this portion of the project, we decided to use the Z&F 6000 laser scanner. The difference in the scanners we used is significant and operation of both scanners on this project highlighted those differences. The range on the Z&F scanner is dramatically superior to the FARO. This allowed us to capture targets and detail of areas that we couldn't capture with the FARO. An area that we could capture in 2 scans with the Z&F would take 4 or 5 scans with the FARO. In some ways, the range of the Z&F makes up for the size and lack of mobility when compared with the FARO, in theory. (...Try telling that to a person(s) who are carrying the scanner and supporting equipment up and down several flights of stairs.) Given the lighting problems we encountered inside the house, the colorized laser scans would be more problems than they were worth. Though the Z&F scanner does not have a built in camera, it also doesn't have a lot of settings and options. It is pretty straight forward; set the scanner resolution, press the button and let it do it's job. Operating the FARO 3D Focus takes much more consideration and requires attention to the settings before each scan in order to guarantee the best quality product.
Custom Redwood Bookshelves
Kelley House Library


Combining the data from two different scanners used to be problematic however FARO Scene does except data collected from Leica and Z&F scanners. The key to processing the data is to convert the scans to aPTX. file. We are currently processing the data; registering all 120 scans from both scanners in FARO Scene. We expect to have the project completed and turned over to our client by the first of next week...Stay tuned for the next step in the Kelley House Project.https://www.facebook.com/pages/Reality-Capture-Technology-Training-Center-at-History-Park/304789553009310

2 comments:

  1. Hi, I would like to volunteer recreating a realistic 3D model of the Kelleys Home. I am a professional 3D modeler with a degree in architecture and design.

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  2. That's great! This is late notice however I'd like to invite you to our technology demo next Friday December 11th at History Park. The demo will start at 1:00pm and will feature some of the point cloud data we've collected over the years, including the Kelley House. There will be representatives from city and county agencies as well as museums. I love to meet you if you have time.
    Otherwise, please contact me at your convenience brianmiller@nventum.net.

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