Tableau — You made my DAE

There are times where the stars and planets align and CLICK! an Einstein moment occurs.

For me, it was the 2nd glass of rose and receiving a reply on a question about David Murphy’s (Datasaurus Rex) Donuts.

So off I went to look at Blender! ( https://www.blender.org/). As a Unity3D programmer, I’m impressed! and will be using this to build some objects for my next project in AR.

The Einstein Moment.

Blender can Import DAE! Also known as COLLADA files and can export STL files. STL simply stands for STereoLithography, or simply Standard Triangle Language.

An STL file describes a raw, unstructured triangulated surface by the unit normal and vertices (ordered by the right-hand rule) of the triangles using a three-dimensional Cartesian coordinate system.

The 2nd Einstein Moment

Google Earth files, KMZ are nothing but Zip files.

The Tutorial

A video of the process can be found here: https://youtu.be/nDrKOxH5wHg

Download the workbooks here: https://public.tableau.com/profile/frjones#!/

Step 1.

Navigate to Google Earth desktop app and find the area of interest. In this tutorial, I decided to use the Sydney Opera House (mainly because I live in Sydney, and why not!)

Step 2 — Export KMZ file

To export a KMZ file, follow these steps (Use the desktop version):

1. Select File > Export > 3D Model. The Export Model dialog box appears.
2. Navigate to the location where you want to save your KMZ file.
3. From the drop-down list, select Google Earth File (*.kmz).
4. (Optional) In the File Name box, type a new name for your file.
5. Click the Options button.
6. (Optional) Select the Export Hidden Geometry checkbox to export your model’s hidden geometry.
7. Click OK in the KMZ Export Options dialog box.
8. Back in the Export Model dialog box, click Export and your KMZ file is saved in the location you selected.

Step 3 — Unzip your KMZ File

1. Located your KMZ file.
2. Right-click it, and rename the file extension from .KMZ, too.ZIP.
3. Unzip the file to your preferred location.
4. You should see something that looks like this:

Double click on Models and you will see that the file is made up of a .DAE and Texture files

Step 4 — Open Blender

1. Once Blender has been installed, you can open it, and will be greeted with a screen full of pre-made objects.

2. Delete these object by Right clicking them in the scene and selecting delete. do this for World, Camera, Cube, Lamp

Step 5 — Import COLLADA

1. With the objects now removed, click File> Import > COLLADA (.dae)
2. Don’t worry about not being able to see the image on the screen.

Step 6 — Export STL

1. Go to File > Export > STL (.stl)

REALLY IMPORTANT.

2. Click on ASCII before exporting

The STL file format appears capable of defining a polyhedron with any polygonal facet, but in practice, it is only ever used for triangles, which means that much of the syntax of the ASCII protocol is superfluous, so we only really use it for its suitability of converting into TDE via Alteryx

Check out the Binary and ASCII formats here: https://en.wikipedia.org/wiki/STL_(file_format)#ASCII_STL

3. Export to your preferred location.

Step 7 — Alteryx it!

I’m not going to show you the workflow (unless you want me too — let me know!) that you need to build in Alteryx, as there is a nicely built tool that has existed for years in the Alteryx Gallery that we can use. Thanks, Phillip (I can’t find any social media links for Phillip to give Credit)

1. Navigate to https://gallery.alteryx.com/#!search/STL

2. Hit ‘Run’ (Or download if you want to have a look at the Model).

3. select your file and allow the screen to finish loading before you hit ‘Run’

4. Click on the Tableau TDE to open it.

Step 8 — Tableau!

You should see something similar to this.

1. Convert the ‘Subpoly’ Measure to a Dimension.

2. Copy across the fields from this workbook:

3. Assign geographic roles.

X_Rotated — Longitude

Y_Rotated — Lattitude

4. Add X_Rotated to the Rows shelf, and Y_Rotated to the Columns Shelf, and make them both Dimensions

5. Add the Parameter controls. You should have something that looks like this:

6. Change the MARKS to Line, the SIZE to the smallest,

7. Add the ‘Path order’ to Path, and select MIN

8. Add SubPoly to Details and select ‘Add all members’

9. Do the same for Vertex ID.

10. Now you have a wireframe that should look like this:

11. Duplicate X Rotated and change the Mark time to Polygon. Play with the transparency and color until you get the desired look.

And there you have it!

Let me know if you want to explore STL files in more detail, or understand the structure of the data. I’ll add it to the post.

Tag me on Linkedin as I’d love to see your creations! & Feel free to reach out if you have any questions.

Frances Jones | LinkedIn

Youtube: https://youtu.be/nDrKOxH5wHg