Tech Tuesday: Bridge of Lions
Ever wonder what we get into when we say "Tech Tuesday?" It is time we set aside to work on digital aspects of archaeology- 3D printing, photogrammetry, laser scanning, and 3D modeling.
The past two Tech Tuesday have been focusing on the Lions that guard the Bridge of Lions in St. Augustine. They are named Firm and Faithful, although we do not know which one is which. Since this process has taken multiple days, why not take you through the process step by step?
Step 1: Data Collection
The data collection is the most critical, if scans or photos do not work, we will have to go back into the field, but if the lighting has changed, we might be left with a collection of useless data.
The day in the field was perfectly overcast, no shadows, cool (some would even say cold), and with just a slight threat of rain.
The lighting was key. We were able to collect the digital data without fear of shadows or glare.
The first data we collected was with the FARO laser scanner. What this does is collect accurate measurement data in 360 degrees up to 40m away (during data processing we accidentally collected data upwards of 70m).
The second set of data collected were over 500 photos to make a photogrametric model. This data was collected to create more detail in the final project.
Step two: Data upload
This is where we spend far too long on a computer uploading the data in the software.
We use this time to use all the computers and multitask.
Step 3: Data Processing and Cleaning
The FARO collects 360 degrees of data every time you run the scan, when you take 8 scans to capture one specific area or object, you collect a lot of unnecessary data.
You have to go through and clean the data, deleting extra points and making sure all the scans have aligned to make he 3D model.
The rest of the steps all rely on the accuracy of the scan data collected, and the software to do the matching and model creation.
Step 4: The Model
Not everything works out so perfectly. During our data collection we had to leave early due to rain, and we did not have any tools that could allow us to photograph the top of the lion.
Which is why our model is wearing a hat.
The software connects all the points, but if you are missing data, it tries to assume where the next point is. There were still some floating dots which is why there is a strange hat.
After a bit more cleaning, and filling in the hole, we were able to get a model of Firm or Faithful!
Unfortunately, we were unable to build the texture, or the areas with color. We are still working out the kinks, and I do not believe it was the fault of our data, rather the software update!
We will see.
Step 5: Printing
Since we did not have the texture, the model was not posted online, but what we did have allowed us to try out the model in the 3D printer.
The model successfully printed (taking just under 5 hours) and now we have to scale replicas of Firm and Faithful!
Now why was this necessary? This was all a practice day, learning how to use these tools allows us to further document archaeological sites, historic structures, and artifacts for preservation and education.
If something were to happen to one of the lions; damage from a storm, vandalism, general decay and lack of maintenance. We now have a to scale model an artist could recreate to a millimeter accuracy, or we could 3D print one to scale!
The next step is to clean up the model and apply paint. Then we will have a perfect replica!
All photos and text by FPAN Staff, Emma Dietrich
The past two Tech Tuesday have been focusing on the Lions that guard the Bridge of Lions in St. Augustine. They are named Firm and Faithful, although we do not know which one is which. Since this process has taken multiple days, why not take you through the process step by step?
Step 1: Data CollectionThe data collection is the most critical, if scans or photos do not work, we will have to go back into the field, but if the lighting has changed, we might be left with a collection of useless data.
The day in the field was perfectly overcast, no shadows, cool (some would even say cold), and with just a slight threat of rain.
The lighting was key. We were able to collect the digital data without fear of shadows or glare. The first data we collected was with the FARO laser scanner. What this does is collect accurate measurement data in 360 degrees up to 40m away (during data processing we accidentally collected data upwards of 70m).
The second set of data collected were over 500 photos to make a photogrametric model. This data was collected to create more detail in the final project.
Step two: Data upload
This is where we spend far too long on a computer uploading the data in the software.
We use this time to use all the computers and multitask.
Step 3: Data Processing and Cleaning
The FARO collects 360 degrees of data every time you run the scan, when you take 8 scans to capture one specific area or object, you collect a lot of unnecessary data.
You have to go through and clean the data, deleting extra points and making sure all the scans have aligned to make he 3D model.
The rest of the steps all rely on the accuracy of the scan data collected, and the software to do the matching and model creation.
Step 4: The Model
Not everything works out so perfectly. During our data collection we had to leave early due to rain, and we did not have any tools that could allow us to photograph the top of the lion.
Which is why our model is wearing a hat.
The software connects all the points, but if you are missing data, it tries to assume where the next point is. There were still some floating dots which is why there is a strange hat.
After a bit more cleaning, and filling in the hole, we were able to get a model of Firm or Faithful!
Unfortunately, we were unable to build the texture, or the areas with color. We are still working out the kinks, and I do not believe it was the fault of our data, rather the software update!
We will see.
Step 5: Printing
Since we did not have the texture, the model was not posted online, but what we did have allowed us to try out the model in the 3D printer.
The model successfully printed (taking just under 5 hours) and now we have to scale replicas of Firm and Faithful!
Now why was this necessary? This was all a practice day, learning how to use these tools allows us to further document archaeological sites, historic structures, and artifacts for preservation and education.
If something were to happen to one of the lions; damage from a storm, vandalism, general decay and lack of maintenance. We now have a to scale model an artist could recreate to a millimeter accuracy, or we could 3D print one to scale!
The next step is to clean up the model and apply paint. Then we will have a perfect replica!
All photos and text by FPAN Staff, Emma Dietrich