Top considerations when deciding on a 3D mapping platform

3D maps are clearly the future digital maps. While the major global digital map providers such as Apple, Google and TomTom have platforms that allow for 3D experiences, I wanted to explore some of the options available for how you can build a similar experience. The commitment from these companies suggests that the advent of a more immersive mapping experience is upon us: Apple has released a new 3D map that allows for you to explore cities in 3D, Tom Tom has shifted it's focus and created a new HD mapping platform, and Google has been in the forefront for many years in providing different types of 3D experiences. However, each of these experiences are not available to developers, so we must rely on companies like Mapbox, ESRI and Cessium, that have been building platforms tailored to developers that allow us to create similar experiences. Additionally, there are some very simple ways to provide a high quality 3D view without too much technical support.

Imagery

Beyond the use of satellite data, the easiest way to get a 3D experience is using Google's 45 degree imagery. While satellite imagery is looking straight down, the 45 degree imagery gives you sense of depth to the buildings. The use of Googles imagery has been a feature of the Concept3D platform since it's availability, and, depending on your location, offers a compelling experience. There are two basic controls available through the API: you can turn the imagery 90 degrees, as well as tilting the map. If your map uses custom renders such as ours, they will also conform to the controls. Another attempt at this type of display is to use custom image and embed hotspots over the buildings to create a "pseudo-map", but still have the visual representation of three dimensions. These maps lack the controls found in more advanced mapping platforms, such as the ability to view from different angles, as well as overlaying other types of geographic information.

Extrusions

Extrusions are borne out of Open Street Maps (OSM), and relies on layering a series of polygons and specific tags to describe the height, color, building material, shape as well as other features, such as the shape of the roof. Several different companies use this as a 3D building option, including Mapbox. In addition to using data from OSM, Mapbox does allow you to add your own extrusion data into their platforms. Mapbox's solution is dependent upon the mapboxGL library, but there are also other open source libraries that use OSM extrusion data, most notably F4 map and osmbuildings.org. Whichever platform you choose, there are limits to its functionality. I have put together a comparison of the three platforms showing Coors Field in Denver, CO.

It should be noted that I could add color to the Mapbox version, but that would have to be done in their studio product. Both F4 and OSM Buildings use the color tags included in the OSM models. As you can see, while each solution does a good job at using the extrusion data from OSM, F4 maps uses more of the meta-data about the building, as well as adding trees, animations for construction zones and chimneys.

3D Models

MapboxGL can do far more than display extrusions. The true power of the Mapbox platform is its ability to augment the extrusion data with 3D models that can be in the form of LIDAR data or popular formats such as GLB or glTF. Adding LIDAR data is a bit more complex than working with GLB and glTF data, the later can be added onto the map as a layer, while LIDAR data requires the use of other GIS tools as well as additional libraries. I prefer the models because they act as an additional layer on the map, making it easy to work with any data you may have within the vector tiles or additional layers, such as way finding routes. A great example of this was the Space X example we put together for the Mapbox Conference: Creating a 360° 3D rendering of the SpaceX launch facility

Using this technique, you gain a lot of the features that you find in the proprietary solutions: the ability to spin the map, using different pitches and angles, animations, and a true mapping platform, yet it comes with better control of your content. There is one important geographic feature missing from Mapbox that Cessium provides: Terrain. In addition to loading glTF models onto their platform, the addition of Terrain adds a level of realism to the map that a flat surface can't provide. Depending on where your campus is located, this could be critical.

ESRI

Being the leader in GIS platforms, you should expect that ESRI has a 3D offering. The CityEngine platform is a similar modeler as extrusions, however, being hosted within the ArcGIS ecosystem gives it an advantage of visualization, data integrations, and modeling capabilities. The main difference is cost: other than Cessium, the solutions I have mentioned are either open sourced, or come with a consumption cost for the use of vector data and API calls. Another difference is that ESRI comes loaded with a toolkit that allows for loading of 3D models from popular tools like sketches, while the other solutions rely on conversion to other 3D modeling formats. Take a look at the George Mason University project to get an idea of the capabilities.

Summary 

With improving mobile and browser technology, the movement towards 3D visualizations on digital maps is picking up. The largest mapping providers have proprietary solutions that have not made it into their mapping API's just yet, but with some development resources and an understanding of extrusions and 3D modeling, you can create compelling 3D campuses that you can spin in 360 degrees, allowing you to highlight features that have been hidden from view in traditional digital maps. Concept3D will be releasing this feature soon, we have created 360 maps tool that allows you to upload, scale, and place your 3D models on your campus then view them on our frontend. These models will also be available through our API, allowing you to use them in your own GIS systems.