How to pose a Map

Please note that this blog post is also hosted by John Nelson on his profile on Esri blog with the title Digital map folding part 2: 3D.


What first inspired me to start researching all this, was the need to photoshoot my maps for the portfolio section of my new website (which is under the “coming soon” state for a very long time, but this is another story).

At first, I was contacting photographers, explaining my needs and asking for their offers and stuff like that. But a lot of things worried me, like whether the outcome would be good for a map portfolio, or what if I change my mind and I want another perspective of that map or the other etc etc and I couldn’t decide how to proceed, not to mention a couple of unsuccessful attempts to picture these maps myself with my phone (a complete disaster).

I was thinking there must exist another way. I knew I could find a way to simulate an oblique realistic view of a studio photographed map, like a mockup. I started searching the internet for alternative solutions, mostly by looking for tutorials for Photoshop or Illustrator, which – to my surprise – were a lot out there, all of them showing, more or less, a similar process on how to produce such a mockup. Reading/watching these made me wonder whether I could apply these techniques in ArcGIS Pro.

So after lots of late nights and tens of hours in front of my computer, I managed to simulate the folds, the shades and a realistic oblique view of a real paper map, reaching a satisfactory result (I think). In the following paragraphs I will demonstrate the process that I have adopted so far, which of course is subject to improvement.

Simulate the third dimension

I continue narrating from the point my previous post “How to fold a Map” ended. So, I have already created the grid polygon feature layer, which simulates the folds, and I have rendered it with my standard ArcGIS Pro Style and I am sitting (un)comfortably staring at my screen.

OK, it looks realistic, but why only produce a top view. If I had given a map to a professional photographer, they would take it to their studio and they would probably shoot a number of oblique aspects, aside the top view. So, I need to find a way to simulate this.

I know that the Scene View in ArcGIS Pro offers an awful lot of possibilities, provided I feed it with the proper Elevation Surface. But how can I produce such an elevation source?

Understanding the folds’ vertices

Let’s get my hands on. In ArcGIS Pro I open the Map View of the map I have been working so far, and I add once again this super handy grid polygon feature layer, which simulates the folds.

In order to understand the folds’ vertices, I will symbolize this polygon layer with a marker symbol layer, which I give an “On vertices” placement.

What I observe here is that some vertices look like they pop out of the map, while others look like they dive into the map. A point feature layer with these vertices and some appropriate elevation values could produce an elevation surface for the Scene View.

Creating the folds’ vertices

If you happen to possess an Advanced ArcGIS Pro license, then you may use the Feature Vertices To Points tool to create the desired layer.

Since I (and the rest of us mortals) only have a Basic licence, I will manually create it. So I create a new point feature layer with the Create Feature Class tool and I create a new attribute field to store the elevation values.

Then I add it in the table of contents.

With edit commands and with the vertex snapping option enabled, I manually create the points.

Assign elevation attributes to vertices

Next step is to group the vertices in those that pop out of the map and to those that dive into the map. I am doing this with a simple selection on canvas and with the Calculate Field command.

I give a value of 200 to the vertices that pop out of the map and a value of -200 to the vertices that dive into the map.

The values -200/200 are subjective. They actually represent the distance of the vertex from the horizontal plane. In other words, if I unfold a paper map and spread it on a table in a way that its entire surface touches the table, these values trend to zero. You might need a little trial and error to find the most suitable values for your own case.

Creating the Elevation Source

ArcGIS Pro Scene View allows a number of different Elevation Sources. So I can produce one by interpolation of the point feature layer, which I created at the previous steps.

Again, there are a number of ways to do this. Provided you have a Spatial Analyst or a 3D Analyst Extension, you may simply create a TIN surface, or interpolate with IDW or Spline or any other method. Each option will produce a different result so you might need to experiment a bit.

I do not possess any of these extensions in my personal licence, so I perfomed the interpolation in SAGA GIS. The outcome elevation raster should be something like the one at the following picture.

Convert to Scene View

Now that I have set the Elevation Source is where the real magic starts to happen. I simply convert the map to a Local Scene View.

Then I drag the elevation layer and drop it in the Ground group at the Elevation Surfaces group at the very bottom of the table of contents.

I remove all the layers that I no longer need, such as the vectors created at the previous steps, as well as the default WorldElevation3D/Terrain3D at the Elevation Surfaces group and I rotate/tilt the view to find a nice aspect!

Refine the Scene View

There are a few more refinements I must make to turn this look realistic. Firstly, I must decrease the vertical exaggeration a little (apparently the -200/200 values were larger than they should), so I go to the vertical exaggeration box and change the value from the default 1.00 to 0.40!

Much better, but it still doesn’t feel perfectly right, because the map looks like floating in space. So a subtle cast shadow underneath the map should correct this. Simply, I load the (what else) grid polygon layer, which I know it covers exactly the extent of my map, and I drag it to the 3D Layers group at the very top of the table of contents.

At the Layer Properties panel, at the Elevation tab, I select these features to be At an absolute height and I adjust the Additional feature Elevation using an expression via the Expression builder. I actually tell Pro to push horizontally that layer 200 map units below the map.

And since it is pretty unlikely to see anywhere in the physical World a pink shadow (unless you are the Pink Panther), I will change the style of the layer, which I rename to shadow, to something closer to an actual shadow.

Et voila!

Final touch, the Background color of the map!

And that’s it!

How to pose a Map

Thank you so much for reading! I really hope you enjoyed it!

Kindest regards from Crete, Greece

Spiros