Topography – Master of Spatial Analysis

by Scott Mackey, Geovis Project Assignment @RyersonGeo, SA8905, Fall 2016

Since its first iteration in 1984 with Charles Hull’s Stereo Lithography, the process of additive manufacturing has made substantial technological bounds (Ishengoma, 2014). With advances in both capability and cost effectiveness, 3D printing has recently grown immensely in popularity and practicality. Sites like Thingiverse and Tinkercad allow anyone with access to a 3D printer (which are becoming more and more affordable) to create tangible models of anything and everything.

When I discovered the 3D printers at Ryerson’s Digital Media Experience (DME) lab, I decided to 3D print models of interesting Canadian topographies, selecting study areas from the east coast (Nova Scotia), west coast (Alberta), and central Canada (southern Ontario). These locations show the range of topographies and land types strewn across Canada, and the models can provide practical use alongside their aesthetic allure by identifying key features throughout the different elevations of the scene.

The first step in this process was to learn how to 3D print. The DME has three different 3D printers, all of which use an additive layering process. An additive process melts materials and applies them thin layer by thin layer to create a final physical product. A variety of materials can be used in additive layers, including plastic filaments such as polylactic acid (PLA) (plastic filament) and Acrylonitrile Butadiene Styrene (ABS), or nylon filaments. After a brief tutorial at the DME on the 3D printing process, I chose to use their Lulzbot TAZ, the 3D printer offering the largest surface area. The TAZ is compatible with ABS or PLA filament of a 1.75 mm diameter. I decided on white PLA filament as it offers a smooth finish and melts at a lower temperature, with the white colour being easy to paint over.

The next step was to acquire the data in the necessary format. The TAZ requires the digital 3D model to be in an STL (STereoLithography) format. Two websites were paramount in the creation of my STL files. The first was GeoGratis Geospatial Data Extraction. This National Resources Canada site provides free geospatial data extraction, allowing the user to select elevation (DSM or DEM) and land use attribute data in an area of Canada. The process of downloading the data was quick and painless, and soon I had detailed geospatial information on the sites I was modelling.

geogratis — GeoGratis Geospatial Data Extraction

One challenge still remained despite having elevation and land use data – creating an STL file. While researching how to do this, I came across the open source web tool called Terrain2STL on a visualization website called jthatch.com. This tool allows the user to select an area on a Google basemap, and then extracts the elevation data of that area from the Consortium for Spatial Information’s SRTM 90m Digital Elevation Database, originally produced by NASA. Terrain2STL allows the users to increase the vertical scaling (up to four times) in order to exaggerate elevation, lower the height of sea level for emphasis, and raise the base height of the produced model in a selected area ranging in size from a few city blocks to an entire national park.

The first area I selected was Charleston Lake in southern Ontario. Being a southern part of the Canadian Shield, this lake was created by glaciers scarring the Earth’s surface. The vertical scaling was set to four, as the scene does not have much elevation change.

Once I downloaded the STL, I brought the file into Windows 10’s 3D Builder application to slim down the base of the model. The 3D modelling program Cura was then used to further exaggerated the vertical scaling to 6 times, and to upload the model to the TAZ. Once the filament was loaded and the printer heated, it was ready to print. This first model took around 5 hours, and fortunately went flawlessly.

Cape Breton, Nova Scotia was selected for the east coast model. While this site has a bit more elevation change than Charleston Lake, it still needed to have 4 times vertical exaggeration to show the site’s elevations. This print took roughly 4 and a half hours.

Finally, I selected Banff, Alberta as my final scene. This area shows the entrance to Banff National Park from Calgary. No vertical scaling was needed for this area. This print took roughly 5 and half hours.

Once all the models were successfully printed, it was time to add some visual emphasis. This was done by painting each model with acrylic paint, using lighter green shades for high areas to darker green shades for areas of low elevation, and blue for water. The data extracted from GeoGratis was used as a reference in is process. Although I explored the idea of including delineations of trails, trail heads, roads, railways, and other features, I decided they would make the models too busy. However, future iterations of such 3D models could be designed to show specific land uses and features for more practical purposes.

3D models are a fun and appealing way to visual topographies. There is something inexplicably satisfying about holding a tangible representation of the Earth, and the applicability of 3D geographic models for analysis should not be overlooked.

Sources:

GeoGratis Geospatial Data Extraction. (n.d.). Retrieved November 28, 2016, from http://www.geogratis.gc.ca/site/eng/extraction

Ishengoma, F. R., & Mtaho, A. B. (2014). 3D Printing: Developing Countries Perspectives. International Journal of Computer Applications, 104(11), 30-34. doi:10.5120/18249-9329

Terrain2STL Create STL models of the surface of Earth. (n.d.). Retrieved November 28, 2016, from http://jthatch.com/Terrain2STL/

By Nicole Serrafero

Geovis Project Assignment @RyersonGeo, SA8905, Fall 2016

When learning about geography in the early years of school we had to trace and label contours based off topographic maps. For the purpose of the course work I decided to take inspiration from my younger school days and use modern technologies to attempt to reproduce a topographic map with cartographic elements included. My main inspiration came from an artist by the name of Sam Cadwell who creates beautiful works of arts using layers of paper to represent contours. An example of his work can be seen below and through the link to his website.

Example of Sam Cadwell's Work

The project involved cutting out each contour layer and features using a Cricut machine which is computer guided paper cutter (seen below).

The maximum paper size that the cutter program can handle is 11” in x 11” so I ensured that the study area would fit within the paper size limitations. The paper used for the project was 12”x12” cardstock paper in a variety of colours to represent each feature. For the layers of contours, a pink to red colour scheme was used as it provided me with up to 15 layers of sequential colours.

The water features were blue, the rail features yellow, the buildings a light purple, and the roads black.

Data Used

Four (4) datasets were used to produce the topographic model:

Contour Lines (Obtained from TRCA)
Building Footprints (Obtained from DMTI spatial)
Waterways (Obtained from TRCA)
Road and Rail Lines (Obtained from Statistics Canada)

Study Area Extraction

All of the files were loaded into ArcMap then all projected to WGS84 to ensure all files were in the same projection. The Evergreen Brick Works was chosen as the study area as its surrounding area contains interesting contours, roads, a major highway, railways, a river. To ensure that the study area was contained within the paper limitations the page size within ArcMap was set to 11” x 11” and the map view was adjusted until I was satisfied with the area. Once the final study area was chosen the features within the view were clipped out and saved as separate files. Below is a screen shot of what the final study area covers.

studyarea_ns

With the data now clipped the further data processing could be done easily as the amount of data was significantly reduced. The contour lines came as 1m intervals with a range of 22 individual contours levels which is too many levels for the amount of paper that I have available for the contours. The number of contours was reduced by selecting every 4 m contour then extracting the selected lines to a separate file. With the new file the number of layers was reduced to 12 layers which fits within my 15-layer limit. The remaining files did not need further processing within ArcMap.

The next major step to get the files ready for the paper cutter. To do this all layers were saved as scalable vector files (SVG) for each data set. To accomplish this all layers were turned off except for one dataset. Then the Export Map option was used to save the map area as an SVG file. The SVG files were then imported into a program called Inskscape to be edited further. Within the Inskscape program the contours were divided up into their individual 4m interval layers (seen below).

layers_ns

Some of the smaller contour lines were deleted as the cutter would not be able to cut the shape out. The other features were given a layer of their own as well. Each individual layer was then exported and saved as an 11”x11” page in JPEG format. The program used to work the paper cutter did not work as well with files that came from ArcMap directly which was why Inkscape was used. It is also easier to edit/select the lines and change the thickness within Inkscape.

Printing and Assembling the Model

To cut our each layer the JPEG layers were imported into the paper cutter program. Each layer was placed on the canvas then the corresponding colour was placed on the cutting map and loaded into the machine. Once loaded the paper cutter proceeded with cutting the paper. An example of what a cut layer from the machine can be seen below.

The contours were cut first followed by the river, then the roads and railway and last was the Evergreeen Brick Works buildings. Each contour layer was stuck together using foam spacers that had tape on each size. These spacers were used to create the illusion of height in the model. The remaining paper features were stuck on using double sided tape. The following images show the assembling process.

Once all of the paper layer were assembled the legend, scale, north arrow, and labels were added by hand. The final product can be seen below.

Tag: Topography

3D Printing Canadian Topographies

3D Paper Topography Map of Evergreen Brick Works and Its Surroundings