Analog to Digital and Back

In groups: spend 5 minutes exploring one of the following 3D modeling/printing projects below or the Book of Fortresses and Battle of Mount Street Bridge projects I asked you to explore and read about for today:

Designate a reporter and answer the following 4 questions on a stretch of whiteboard:

  • How do the analog and digital interact in this project?
  • What new perspectives does it develop on presentation to diverse audiences?
  • What new arguments or interpretations does it advance?
  • What new possibilities does it suggest for your future work?

3D Printing and Fabrication

One of the biggest advances in recent years has been the democratization of 3D fabrication through consumer grade technologies like 3D printers, CNC routers and mills, and laser cutters. These tools allow digital 3D models that were previously only viewable through the imperfect 2D interface of a monitor screen or a 3D Virtual Reality headset to be brought into physical reality fairly easily and cheaply.

Svitlana Lozova [CC BY-SA]

Plastic Buildings and Wooden Maps

In this class, we are going to explore 3D fabrication by taking advantage of our brand new Makerspace in Anderson Hall, and the expert guidance of its manager, Aaron Heidgerken-Greene.

The last pre-pandemic class was able to use the Maker Space to make a hybrid digital/physical 3D model of Carleton’s Campus. This project moved back and forth across the analog/digital divide as we…

…researched the history of the physical buildings on Carleton’s campus to create a digital repository of archival images for each.

Digital repository of archival images

… refined a 3D digital model of each building that previous students working with our GIS Specialist Wei-Hsin Fu and our Academic Technologist for Digital Scholarship Andrew Wilson had already made.

An interactive 3D map of (most) Carleton College buildings

… made a GIS digital map of campus with contour lines for topography, and buildings color coded by use: residential, academic, or other.

… 3D printed tiny physical versions of the digital building models

3d printing building models

… and positioned them on a physical version of the digital map laser cut out of wood

Laser cut wood campus map with plastic 3D building models

… and finally linked the physical product to the digital repository via a QR code in the lower right portion of the map, so viewers can read more about each building and the sources underlying the reconstruction.

This year, you are all guinea pigs in launching a new ambitious effort to begin 3D modeling/printing and exhibiting objects from the Carleton archival, library and museum collections. We will experiment with individual components today, and you can consider what you might do along these lines in your future work.

ASIDE: Modeling Historic Buildings in SketchUp

For our the campus building project we used architectural buildings in SketchUp that were made by hand from old photographs. You modeled your own home from memory, but you can use SketchUp to make much more accurate models using the techniques below. Guidance and resources are offered here for those who might want to explore these techniques for their final projects.

Match Photo

SketchUp’s Match Photo technique can be used to create models of historic buildings. Sadly, the tool is no longer available in the free, browser-based edition, but is still accessible in pro and older versions.

The clearest step-by-step introduction I’ve found to the Match Photo technique of geomodeling is several years old but the basic principles still apply.  The first link takes you to step-by-step instructions for the process using a photo of a barn as an example, and the next two link to videos walking through the same example.

The two videos below are more recent match photo tutorials that show how to incorporate multiple photos, but skip over some of the basic steps outlined above.

Extruded Footprint

The other method often used to model existing buildings is the “Extruded Footprint” technique, which has the benefit of georeferencing your model with Google Earth from the outset. Again, this method has been lessened since Trimble acquired SketchUp, but the details are here if you want to try.

 If your building is still standing and visible in Google satellite imagery, then this method might work as a starting point for you, but it won’t provide the level of detail we want unless you combine it with matched photos to add the photo textures and architectural elements.  The video below offers an excellent introduction to how these two techniques can be combined to produce an accurate model, in the same way we practiced together in class.

We are primarily interested in exteriors for this class, but if you find floor plans or architectural blue prints for your building in the archives and want to go nuts and try to start modeling a version with the interior walls, go for it.  Here are a few basic resources to get you started.

Finally, has compiled a handy list of 10 tips every SketchUp modeler should know.

Processing a 3D model for printing

In order to print successfully a 3D model needs to be an entirely enclosed solid. That means it needs to be:

  • Watertight (i.e. have no holes)
  • Non-zero width (i.e. cannot be a true 2D plane)
  • Oriented correctly (i.e. cannot have “reversed faces”)

In addition, the model should be set up with its origin centered, so that the model will import and rotate easily in printers or other 3D viewing/editing software.

There are many ways to clean an STL file, which is the preferred format for 3D printing, that range from free software to very expensive licensed options through Autodesk and other companies. SketchUp itself has a Solid Inspector tool for this purpose, but it is only available for the paid tiers.

We will be using a dedicated free service from Formware to optimize for printing.

EXERCISE: Optimizing models for printing (SketchUp 201)

  1. Log back into SketchUp at
  2. Load your house project

Isolate geometry to be printed

  1. Select the building and only the building itself, unselecting any landscape or animal features you may have modeled and don’t want to print (remember the marquis select tools are your friend).
  2. Right click the selection and choose Make Group to make it unsticky and move as one
  1. Copy the Grouped Model to the Clipboard
  2. File > New to make a new model file for printing
  3. Paste the model in, and hover over the Origin, then left click, or right click > Place
  4. Select & delete the scale person model.
  5. Save your project as LastName_House_print

Clean your model

First we’ll need to fill any holes to make a solid, then reverse faces and clean up any stray geometry

  1. Rotate your model to find any missing faces, e.g. the floor
    1. You can fill these by drawing new faces with the rectangle tool, or lines with the pencil tool
Adding a floor with the rectangle tool

Now we need to reverse faces. Sketchup lets you have faces either way, but most rendering software only “sees” one side of a plane and renders the reverse as transparent. Front and back faces are an issue with SketchUp, so we need to flip these to all face outward for the print to work.

  1. Reverse a new face
    1. Find one of the new faces you just created and see whether it is white or grey. Sketchup renders the reverse as grey, so we need to flip those.
      1. If grey, right click and choose “Reverse Faces”
      2. Once white, right click again and choose “Orient Faces” just below, to flip all to face the direction of the selected.
      3. (This may end up flipping some faces back to reversed or loosing your textures. Continue to reverse any grey faces until all you see are white)
First Reverse Faces to turn grey to white, then Orient Faces to make all match selection
  1. Save your new model as STL and
  2. Click on the file in the Finder or Windows File Explorer and examine the preview. If it looks solid, you should be good

Formware Cleaning

One of the easiest free options to quickly get a clean model for printing: the online Formware service at

  • Go to the Formware service, and upload your stl file
    • You may need to wait for the queue and the file to process.
Waiting for fix…
Fixed! With a nice log of changes
  • Download the cleaned and fixed model, e.g. Mason_House_print_fixed.stl
  • Put the cleaned STL file in your google drive folder

Next week, we will tour the MakerSpace and if you want you can set up a print job to print your model.

Assignment: Final Project 1 — The Pitch (Thursday Feb 17)

Brainstorm your final project ideas and groups

Form a group of 4-6 and chose or invent a project.  Collectively write a blog post on the course blog, stating the following:

  • The definition of the project topic and objectives for what you plan to produce
    • What is the context of your topic?
    • What are you trying to find out? What is(are) your research question(s)?
    • Include a link to one or more DH projects that might make a good model for what you plan.
  • The proposed methodology:
    • Sources: What data do you hope to use and how do you hope to find it?
    • Processes: What tools and techniques will you use to gather sources and store your data?
      • What analyses or transformations will you conduct on those data?
    • Presentation: How will you present the results and integrate the digital assets you create as an interactive final product? What intellectual property issues do you need to be aware of?
  • The proposed timeline of deliverables
    • Following the general project outline, what do you need to do each week?
  • Team Members:
    • Who is responsible for what? Where will you work individually and where will you work collaboratively?

Create a unique tag for your group to tag all your posts going forward.
On your own blogs, write a brief message outlining your personal interests in the projects and what you hope it will achieve, and link both your post to the group one on this course site, and vice versa

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