3D Printing Canadian Topographies

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.

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Lulzbot TAZ

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.

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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.

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Charleston Lake, Ontario
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Cape Breton, Nova Scotia
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Banff, Alberta

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/

 

 

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

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).

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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.

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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.

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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).

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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.

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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.

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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.

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CloudCities 3D Model of the Ryerson Campus

Justin Miron

Submission for GeoVis Project Assignment @RyersonGeo, SA8905, Fall 2016

Interactive City Models

One of the most useful visualization and planning tools used in urban planning and design is the 3D model: a to-scale representation of the built form of a city, its existing (and as-built) conditions and its proposed (or possible) conditions.  A 3D model effectively communicates information about the proportion, size, and distribution of structures and other urban elements, that when well made and presented is intuitively grasped by the people that are viewing it.

A principal drawback to most 3D models is that they are physical models, and they take a lot of time to create, to modify, and can only be shared with an audience who is physically present. One way to solve the this problem is to replace the physical with a 3D digital model (using 3D modelling software such as Rhino, ArchiCAD, Blender, Solidworks, etc.) and to share the models with other users.  Yet, there are drawbacks to this approach, too. For one, these models can only be shared with users that have the same (or similar) software of the kind that was used to create the model. For users who do not have the correct software, static or animated representations of the model are made which, while they can still convey information, do not allow the user make choices on what aspects of the model they want to view or explore.

Beyond this technical problem, the models are not geographic and they are not data-driven. Though they are spatial, they are not referenced to a location on the earth and they don’t contain attributes. There is no way to know what building or open space you are looking at without asking someone who is familiar with the model. Informal exploration is just too limited. One way to solve these problems is to store and view 3D model information in CloudCities.

CloudCities and the Ryerson Campus

CloudCities is a geographically-enriched 3D model viewing and storage platform. The graphical rendering is done through ThreeJS, a javascript library used to build and render 3D objects in a browser. It is one of several platforms that blend geographic information within a 3D environment (see here and here for further examples).

CloudCities allows users to upload 3D model information, such as a building, tree, vehicle, or terrain, as well as their attributes. Not all 3D information can be uploaded (for instance, stylized 3D lines or other non-geographic 3D visualizations are not generally possible). In addition to upload, CloudCities has several customization features that allow the model scene to be modified: sun/shadow settings; pre-set camera views and 3D slides; a search function; location comparison to OpenStreetMap; and dynamic attribute and 3D editing, which allows the user to dynamically modify/add to object attributes and to use basic 3D editing functions.

CloudCities is built to store and view 3D models (as opposed to general 3D visualizations), and specifically 3D models of cities (multiple buildings, blocks, terrain, etc.) so for this project I have built a model of the bulk of Ryerson University’s Campus in downtown Toronto.

Area used for the CloudCities model
Area used for the CloudCities model
A view of the entire model

Data

The input data for the model’s 3D buildings is from two sources: myself, who modelled several buildings on the Ryerson campus, including Kerr Hall, in Rhinoceros (Rhino), a 3D modelling program, and the City of Toronto’s Open Data portal, which maintains a 3D massing and building model dataset that is frequently updated and that is available in several formats.

The 3D information from the City of Toronto is of high quality, but it is released in several formats, and not all of these formats contain equivalent data. Out of all of the data available, the 3D CAD information is the most detailed and accurate but it is harder to work with.

Ultimately, all of the 3D information that fits within the sample area were converted, by individual building, into multipatch features using the ArcGIS 3D Analyst extension. These multipatches were loaded into ArcScene, exported to an ESRI 3D webscene format, and then uploaded into a CloudCities scene. While there are other ways to create a functional CloudCities scene, uploading from ArcScene is the most straightforward, though it is certainly not an option for everyone (see the Asset import tutorial), especially when they do not have ArcScene or 3D Analyst available to use!

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Rhinoceros model of Kerr Hall (above) and a multipatch of the Ryerson Student Center (below)

I manually modelled Kerr Hall because I wanted it to be more detailed than that stored within the City of Toronto dataset. The modelling was done in Rhino. The model was then exported from Rhino into .3DS format, then to multipatch to be included into the webscene uploaded into CloudCities. Deletion of original building massing data from the City of Toronto dataset was required where another model instance – in this case, custom-models like that of Kerr Hall – takes its place. 

Zoning information is also provided by the City’s Open Data portal and this was used to code each building instance with its associated zone category (e.g. R or ‘Residential’).

I have customized and manually refined City blocks (which define the road surfaces) and green open space areas because these are not accurately captured within the City’s data.

Complex Data

Terrain surfaces and trees (which can be very complex objects) were not added to this model because of the eventual data size requirements, but in order for these elements to look good and not awkward, they must be of sufficient detail. Terrain published by the City of Toronto, even when simplified, is a complex geometry that would weigh on the model’s performance. In addition, terrain requires that buildings sit on top of the surface, but the buildings modelled by the City do not account for an uneven grade around the base (what is known as Finished Floor Elevation). While this detail can be made within the models, the eventual time required would have been onerous. The more detail in a building and the more the model approximates reality, the longer the model will take to create.

User Experience (UX) highlights

In the CloudCities model, buildings contain a name, whether they are Ryerson University buildings, the planning zone they fall within (e.g. commercial or residential), and the size of the building footprint area in sq.m. Some of this information is added within the pre-upload ArcGIS environment, but much of it is added from within CloudCities’ editing environment.

These attributes serve as the basis for dashboards and a search bar. The dashboard displays these vital statistics whenever a building object is clicked.

 

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Dashboard reveals attributes when a building is clicked.

Additionally, a search bar and search constraints can be set, and the user can search through the scene’s attributes to highlight objects that are returned. For instance, every building that has the zone ‘Commercial Residential’ is highlighted whenever that term is entered into the search. The search functions are limited, however – there are no advanced queries supported by CloudCities. Instead, various constraints on searches must be set on the back end to make sure that a particular search does not return any object that fulfills any small dimension of the attribute data.

Search results when "Commercial Residential" is entered
Search results when “Commercial Residential” is entered

Specific locations can be saved as bookmarks, and these aid in presentation purposes. These locations can be combined into a slideshow “tour” of the model. This is a particularly relevant feature when sending the model to others, as the locations are stored with the scene, and literally move the user point of view around the model in order to tell a story.

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Camera bookmarks can help guide a user through the model

A sun/shade rendering tool can be implemented, which allows the user to set the time of year and time of day to create a realistic view of how shadows would be cast by model elements based on the model’s location on the earth, although this is not a sun shadow calculator and is meant simply to enhance the experience of the model.

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Sun and shadow controls

Limitations of CloudCities

One of the main limitations of CloudCities is that it is not customizable from a development point of view. A user is limited to pre-set dashboard, search, and styling options. In addition, the platform costs money and is billed at a hefty $60 USD+/per month in order to create a city model to the detail that was made for this post.

The range of 3D visualizations possible is limited. It would be nice to have a platform that incorporates more options for presenting thematic data that goes beyond dashboards and search bars. There is a lot of 3D data that does not manifest itself in a 3D structure. ThreeJS’s gallery of 3D visualizations provides interesting examples of how 3D city modelling could be developed in the future.

Despite these limitations, CloudCities provides an easy-to-use platform for making and viewing 3D city models. I do not believe that CloudCities will always be the only platform that offers the same functionality, but it is currently a really good example of how urban planners and designers can take advantage of geo-technology to create a more interactive and data-rich experience of their 3D information.

The final model can be viewed on CloudCities hereAfter mid-December 2016, the model’s geographic extents will be greatly reduced so that the model can be stored on a free account.

 

 

Developing a 3-Dimensional Model of the Everest Region in Nepal Using Blender

By Matthew Abraham for SA8905 Geovis course project (Dr. Rinner)

This Geovisualization project developed a working 3D model of the Sagarmatha region using graphics and animation software, Blender, culminating in a fly-through of the region outlining all mountains above 8,000m. The purpose of this blog is to detail the steps needed to develop a 3D model of any desired region around the world, using Blender, and is therefore not limited to this one example.

Blender is a free open-source graphics and animation program that has many uses beyond what was explored in this project. Many of their open film projects can be seen on their website at https://www.blender.org/features/projects/. Since this program has incredible diversity in its applications and can create photorealistic imagery, I chose it to produce a 3D mapped mountain environment of the Everest region in Nepal, combining both graphic design and geospatial data. It should be noted that this entire project was done in Blender Cycles (a version of Blender).Technology Blog Pics

This process from geography to 3D model included four critical steps and involved two core programs. The steps were:

  1. Collect geospatial data and identify the size of the region analyzed;
  2. Process this geospatial data within a geographic information system (GIS) – Quantum GIS;
  3. Convert the map to a 3D model using Blender – an open-source graphics animation program; and
  4. Process and develop a fly-through of the desired mountains.

The first step involved extracting digital elevation model (DEM) data from the US Geological Survey website, using http://earthexplorer.usgs.gov/ to define the region of interest. Using a simple search for Mount Everest on Earth Explorer, the region was pulled up. Once the region was located, multiple points were used to help define the regions of interest for data acquisition. Once the region was selected, ASTER DEM data was pulled for all four Lat/Long regions identified by Earth Explorer.

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After downloading the DEM data, it was uploaded into QGIS to merge and crop the four DEM layers to develop the zone of interest. Raster –> Miscellaneous –> Merge was used in order to combine the underlying four DEM layers into one crop-able sheet. Next, a Raster Clipper tool was used to select the desired region from the merged DEM layer as shown below. This clipped section was saved as a TIFF file to be imported into Blender.

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Once the desired DEM region was converted into a TIFF file, the work could begin in Blender. Upon opening up an empty project in Blender, the user is given an empty canvas with a cube in the center of the 3D matrix as seen here:

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The first step involved deleting the cube by pressing X and then clicking “delete”. Next, it was necessary to bring in a blank plane to display the geospatial data. This was done by using the shortcut, Shift-A, and then selecting under Mesh –> Plane. This produced a blank plane in the centre of the grid, where the cube was located.

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The next step was to subdivide the plan into multiple grids. This was done in the Edit Mode by hitting tab and then scrolling down in the Transform sidebar to Subdivide. Subdivide breaks the plane down into as many smaller planes as desired, however the more subdivisions there are, the more information and challenge it is for your computer to handle the detail. For the purpose of this assignment and the limitations of my computer, 500 subdivisions were made to the plane creating over 250,000 squares and 370,000 vertices.

Once the plane was subdivided, the plane was scaled up to a more appropriate size. In order to make it easier to scale up, units were given to the plane by going to the Scene tab and changing the units to “Metric”. In the Transform sidebar, the plane was scaled up to 500 by 500 meters. Although this is not the actual scale of the DEM region we are looking at, it provide enough size and detail to appropriately map the desired region.

After the plane as set up and given an appropriate scale, it was necessary to import the geospatial data onto this plane. This was done by going to the Modifier tab and then selecting a “Displace” modifier from the pull-down menu. Click “New Texture”, and then under Type select “Image or Movie”. Under image, select the TIFF file saved earlier.

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The plane at this point will not show the features, mainly due to the strength of the displacement. This can be adjusted by going back to the Modifier tab and changing the strength of the displace modifier. The strength can be adjusted until the desired look is achieved. It was also necessary to adjust the Z-axis location to be half of the displaced value in order to account for the displacement effects. The following was the result:

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The next step was adding texture to this terrain to give it some realistic definition and colouring. There are multiple methods for texturing in Blender. One step explored in this project was the use of a colour ramp based on vertical height. This was all done in the Node Editor and involved multiple nodes. This first node was a Texture Coordinate, which tells Blender what object the colours will apply to. In this case “Generated” was selected, as it would automatically generate the colours on the desired object. Next a Separate XYZ node was used to separate the desired Z-axis to create a vertical layering of the selected colours. After separating the Z-axis, a Mapping node was added to help further identify the locations of the colours on the object, specifying the Z-axis under Texture. Next a Gradient Texture was used alongside a ColorRamp node to develop the desired colour ranges for the 3D plane. Colours were chosen based on personal examination of the mapped region, going from a dark green and brown for low-lying forests to white for snow-capped peaks. This is all part of a Diffuse BSDF, which is a tool that creates the material for the desired plane. The resulting rendered image shows how the colour ramp looks on the 3D plane.

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The second last thing to add prior to creating the fly-through was the sky texture, which was done by simply going to the World tab and under Surface and selecting “Background” –> “Sky Texture”. The intensity of the Sun and location can be altered using the provided Vector and Colour mapping options. For this project, Ambient Occlusion was turned on as it added more realism to the lighting of the 3D plane.

Lastly, text was added to the map to identify the four mountains above 8,000 meters. This was done through Shift-A, and selecting “Text”. The scale of the text was adjusted using the same method as done for the plane. Next, the text was given 3-dimensions through the Depth option, and the appropriate text was written in Edit Mode. This was then rotated and moved to a location on the 3D model as shown here:

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Once the map was ready, I added camera animations to fly-through the mountains. This was done by first creating a path for the camera to rest on. Once again, this was accessed by pressing Shift-A, going to Curve, and selecting “Path” at the bottom. The desired path can then be scaled and shaped by moving the XYZ vector points of the line.

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Once this path was adjusted to the appropriate location, I added a Follow Path object constraint to the camera under the Constraints tab. After adding the constraint, change Forward direction to “–Z”, and Up to “Y”. In addition to fixing the camera’s orientation, I defined the position on the path by pressing “I” on Offset at “0.000”. Next, I went to Video Sequence view and moved the current frame to the desired end frame (in this case 1600) and then changed the Offset value to “1.000” and once again pressed “I”. This sets the end of the path of the camera at the end frame, 1600.

Next it was necessary to add an Empty object that the camera can track throughout the animation. Once again, Shift-A was used to select “Empty” and then “Plain Axis”. Another object constraint needed to be added to the camera, this time a Track To constraint, which used the same Forward as “–Z” and Up as “Y”. The camera should now be on the path created and pointed at the plain axis. This plain axis could be positioned at any desired region on the map.

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For this project I put this plain axis near the peak of the first mountain and moved it throughout the animation. For each movement, the plain axis was selected at a desired frame by pressing “R” and selecting “Location”. The object was then moved to the second mountain and the frame was adjusted to approximately 200 frames later. Once again, the plain axis was selected by pressing “R” and selecting “Location”. This identified that the camera needed to move to the new location of the plain axis, giving it 200 frames to do so. This process was done twice more to capture the remaining mountains.

At this point it was possible to animate the camera fly-through. In order to do so, a few minor things needed to be done in the Render Tab, including defining the desired resolution (1080p in this example), setting the Start and End Frame to 1 and 1600 respectively, making the Frame Rate 24 frames per second, and choosing an output type. The project was first rendered as pictures or .png files because if the render process crashed, you would be able to continue rendering from the individual picture frame it crashed at. In addition, under Sampling, the samples were increased to help reduce any picture noise caused by light scattering. “Render Animation” was then clicked after all the settings were finalized. The rendering process varies in length and depends on the number of samples, detail of the images, and number of frames. For this project, the render took around 4 hours.

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After the rendering process was complete it produced 1600 individual pictures, which were loaded into Blender’s Video Sequence Editor by locating the folder the render output was saved in and selecting all the image frames. Once uploaded into the Video Sequence Editor, the output type was changed from a .png image to an h.264 file, which is a video output. “Lossless Output” was also selected, and is found under Encoding. Lossless Output ensures that there is no compression in the photos between the original frame and the new video output. This produced the video file of the entire project.

Pic 16         This example demonstrated how to create a 3D model of the Sagarmatha region in Nepal and create a detailed fly-through of the region using the graphics and animation program Blender. This same process can be applied to anywhere in the world with DEM data.

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Thanks for Reading!

 

3D Hexbin Map Displaying Places of Worship in Toronto

Produced by: Anne Christian
Geovis Course Assignment, SA8905, Fall 2015 (Rinner)

Toronto is often seen as the city of many cultures, and with different cultures often come different beliefs. I wanted to explore the places of worship in Toronto and determine what areas have the highest concentrations versus the lowest concentrations. As I explored the different ways to display this information in a way that is effective and also unique, I discovered the use of hexbin maps and 3D maps. While doing some exploratory analysis, I discovered that while hexbin maps have been created before and 3D maps have been printed before, I was unable to find someone who has printed a 3D hexbin prism map, so I decided to take on this endeavor.

Hexbin maps are a great alternative technique for working with large data sets, especially point data. Hexagonal binning uses a hexagon shape grid, and allows one to divide up space in a map into equal units and display the information (in this case the places of worship) that falls within each unit (in this case hexagon grids). The tools used to create this project include QGIS, ArcGIS, and ArcScene, although it could probably be completed entirely within QGIS and other open-source software.

Below are the specific steps I followed to create the 3D hexbin map:

  1. Obtained the places of worship point data (2006) from the City of Toronto’s Open Data Catalogue.
  2. Opened QGIS, and added the MMQGIS plugin.
  3. Inputted the places of worship point data into QGIS.
  4. Used the “Create Grid Lines Layer” tool (Figure 1) and selected the hexagon shape, which created a new shapefile layer of a hexagon grid.

    Figure 1: Create Grid Lines Layer Tool
  5. Used the “Points in Polygon” tool (Figure 2) which counts the points (in this case the places of worship) that fall within each hexagon grid. I chose the hexagon grid as the input polygon layer and the places of worship as the input point layer. The number of places of worship within each hexagon grid was counted and added as a field in the new shapefile.

    Figure 2: Points in Polygon Tool
  6. Inputted the created shapefile with the count field into ArcGIS.
  7. Obtained the census tract shapefile from the Statistics Canada website (https://www12.statcan.gc.ca/census-recensement/2011/geo/bound-limit/bound-limit-2011-eng.cfm) and clipped out the city of Toronto.
  8. Used the clip tool to include only the hexagons that are within the Toronto boundary.
  9. Classified the data into 5 classes using the quantile classification method, and attributed one value for each class so that there are only 5 heights in the final model. For example, the first class had values 0-3 in it, and the value I attributed to this class was 1.5. I did this for all of the classes.
  10. The hexagons for the legend were created using the editor toolbar, whereby each of the 5 hexagons were digitized and given a height value that matched with the map prism height.
  11. Inputted the shapefile with the new classified field values into ArcScene, and extruded the classified values and divided the value by 280 because this height works well and can be printed in a timely manner.
  12. Both the legend and hexagonal map shapefile were converted into wrl format in Arcscene. The wrl file was opened in Windows 10 3D Builder and converted into STL format.
  13. This file was then brought to the Digital Media Experience (DME) lab at Ryerson, and the Printrbot Simple was used to print the model using the Cura program. The model was rescaled where appropriate. My map took approximately 3 hours to print, but the time can vary depending on the spatial detail of what is being printed. The legend took approximately 45 minutes. Below is a short video of how the Printrbot created my legend. A similar process was used to created the map.

The final map and legend (displayed in the image below) provide a helpful and creative way to display data. The taller prisms indicate areas with the most places of worship, and the shorter prisms indicate the areas in Toronto with the least places of worship. This hexagonal prism map allows for effective numerical comparisons between different parts of Toronto.

IMG_5392

Use of a Laser Cutter to Create a 3D Bathymetric Chart

Mallory Carpenter,  SA8905 Geovisualization Assignment, Fall 2015

Bathymetric, or depth data collected about oceans and other water bodies are typically displayed in one of two ways –  as a bathymetric chart, or as a depth raster.  New technologies such as 3D printers and laser cutters allow for the better communication of depth data. Laser cutters in particular allow for “etching,” which can simultaneously communicate topographic data.  This allows the viewer to better situate themselves in the landscape.  Examples of this can be seen here and here.

A fjord is a coastal feature formed by glaciers.  Typically, they contain steep vertical sidewalls, and deep basins separated by shallow sills (ridges of bedrock which rise to depths of less than 50 m).  Mapping Nachvak Fjord in 3D, located in the Torngat Mountains in Labrador, will help to better illustrate the unique bathymetric features.

The basic process is this:

  • Collection and processing of bathymetric data into useable raster format.
  • Importation of the raster data into GIS software.
  • The creation and export of contour data as vector files to secondary graphics.
  • The division of contours into separate layers, and the addition of any graphics for “etching.”
  • Different colours in the vector file are used to differentiate between etching and cutting.

The screenshots below show the bathymetric data collected between 2003 and 2009 by the Canadian Hydrographic Service and ArcticNet. The data are available for free for download from the Ocean Mapping Group website. The spatial resolution of the data is 5×5 m with a vertical accuracy of 1 m. The data ranges in depth from 211 m to 1 m.  Contours were created at 20 m intervals, smoothed and exported as vector files.
The data used for etching the topographic map on the top layer are a product called CanVec, which is downloadable for free from Geogratis. The contour interval was reduced to 200 m to improve visibility. Extraneous shapefiles such as points were removed.

Nachvak1

The data were manipulated in iDraw (a Mac-based vector graphics program) to smooth out overlapping lines and crop to an appropriate area as shown in the following screenshot.

Nachvak2

The laser printer has a 2 x 4 foot printing bed.  In order to save materials and cutting time, layers need to be nested in the bed space, colour coded for cutting and etching, and exported as either a PDF or SVG.  Each contour makes up a layer – with a solid rectangle for the base, and the topographic information etched into the top layer.  The following screenshot shows two cutting surfaces, each with 5 map layers.

Nachvak5

nachvak4

The laser cutting was done at the Danforth Tool Library (http://torontotoollibrary.com), out of 1/4 inch Birch Plywood.  They were cleaned (the cutting produces soot), stained, and glued together with carpenter glue.

Nachvak5

Initial plans included the use of etching to detail habitat and substrate information.  Time and finanical constraints limited the amount of etching work that could be done.  Additionally, if the project were repeated it could be worth either using thinner materials, or increasing the contour interval.  The slope on the side walls is so steep, and the fiord so narrow that the fine details are hard to see in the final version.

Nachvak7

 

Preparation of 3D Cube Paper Model of the Shrinking Polar Ice Cap

Geovisualization Project Blog by Katryna Vergis-Mayo for SA8905 (Dr. Rinner)

For this project, I decided to depict the shrinking of the summer polar ice cap through the use of a 3D cube paper model. The idea came from Peter Vojtek’s 3D paper model of the shrinking Aral Sea, https://petervojtek.github.io/diy/2015/07/14/aral-sea.html.

The process starting from the research to the creation of the 3D Paper model included the following steps:

  1. Collect satellite photographic data depicting the shrinkage of the summer polar ice cap over a selected period of time (1999, 2001, 2002, 2003, 2005, 2008, 2009, 2011 and 2012)
  2. Print the photos for each of the years on letter size paper
  3. Cut out the area of the ice cap (shown in the photos below)
  4. Cut both of the model boards into 4 sections of 10” x 8” to create the inserts for the cube
  5. Trace the cut out of the each stage of the ice cap and the designated area for the year onto the model board
  6. Remove the traced areas with an exacto knife
  7. Cut out letters spelling “Polar Ice Cap” and a snowflake design from the sides of the cube
  8. Paint each model board in a different shade of blue
  9. Write year on corresponding model board with permanent marker
  10. Create the cube and then glue all inserts in chronological order

Data was collected for the years of 1999, 2001, 2002, 2003, 2005, 2008, 2009, 2011 and 2012 from the Earth Observatory website. The data collected was in the form of photographs, and depicts the permanent ice coverage for the corresponding year. Although there is not a drastic difference between each level, it is clear that the permanent ice coverage contracts. The satellite images show that the area of permanent ice coverage in the Arctic during the summer is contracting at a rate of 9% per decade.

The satellite images were collected from http://earthobservatory.nasa.gov/Features/WorldOfChange/sea_ice.php, as shown in the screen shot below.


Screen Shot 2015-11-16 at 4.28.36 PM

The model materials – model paper, exacto knife, glue and paint – were retrieved from Michael’s arts and crafts store.  Some of the materials used are shown in the following photograph. Other materials used were a black and white printer, a ruler and scissors.

Each cut out of the ice cap to the corresponding year was prepared by saving the images, printing the images and cutting out the area of permanent ice coverage (as shown in the photograph above – one can see the example shown by the 2008 permanent ice coverage cut out which was currently sitting on top of all the other cut outs in the right hand corner). The model boards were prepared by dividing two 16 by 20 inch sheets into eight cut outs. A larger sheet was then cut into three pieces to prepare the outside part of the cube (these three pieces were connected; slits were cut in the folds of the paper in order to allow the board to bend nicely). The 3D cube template, shown in the photo below, was the technique that was used to create the model.

Screen Shot 2015-11-17 at 7.10.36 PMRetrieved from: http://styleburb.blogspot.ca/2011/04/fun-family-photo-cubes.html

Once the preparation steps were complete, the model was then ready to make. The next step taken to create the model was tracing each year’s cut out (of the permanent ice coverage) onto the individual model boards (as shown by the second photo). A rectangular section was also cut out for the years to be displayed at each level. This rectangular section became smaller for each layer added (in a descending order), in order to allow the date to be seen at the various levels.

IMG_7629 BETTER

Decorating the sides of the cube was the next step in the process. In order to write “Polar Ice Cap” on the front side of the cube, the letter were first hand drawn onto the paper, than carefully cut out using an exacto knife. On the backside of the cube, a snowflake was hand drawn and once again cut out using an exacto knife. The front and back sides of the cube are shown in the photos to the left and below.

 

After each layer and the sides of the box were cut out, the boards were then ordered in chronological order. The boards were then painted in various shades of blue, as shown in the photo to the left. The corresponding year was then written onto the model board with either silver or black permanent marker (whichever color was more visible on the painted board).

The final step of the process was gluing all the pieces together. IMG_7648The key to this step was ensuring that each of the layers was put in chronological order, and that each layer was the same distance apart. Ensuring that each layer was the same distance apart (1.25 inches to be exact) allowed the model to accurately depict the shrinking of the ice cap.

The piece that was cut out from the top layer was then glue to the top, to give the box an “opening” look. This piece allowed the model IMG_7652to appear as if an individual opened the top layer to look at the depiction of the shrinking polar ice cap through the 3D model, as shown in the photo below. The final dimensions of the 3D Paper model cube project are 8” x 10” x 10”.