Sunday, April 10, 2016

Vector Tiles: The Third Wave

When it comes to web mapping, we are surfing on a third wave in our digital ocean. And the “collaborative processing” between the digital entities while surfing that wave is making the ride more fun, insightful and expressive.

The first web wave was back in the mid 1990s, where interactive maps in the form of html image tags relied heavily on the server and requests parameters to regenerate the image when you clicked on the edge arrows to pan and zoom. Remember MapQuest and ArcIMS ?

Then in the mid 2000s came the second wave or more like a tsunami, Google Maps. You hold down the right mouse button on the map and drag to pan, you use the scroll wheel to zoom in and out, and… when you click on the map, a bubble appears on the map showing the details of the clicked location. Disruptive ! And all was smooth, responsive and AJAXy. This is when I believe that this collaborative processing concept took root and materialized itself in the web mappers’ minds. Soon after, more expressiveness was required as HTML was lacking in power and functionalities and the capitalization on browser plugins emerged to create Single Page Applications. Remember Flex and Silverlight ?

We are now in the mid 2010s. Flash is dead because he ate an “Apple”. HTML5, CSS3 and Javascript are in full swing and though Tile Services are fast as the tile images are preprocessed and prepared to be displayed, they are still image based, and dynamic styling of the features in a tile is not easy. In addition, with the ubiquity of GPUs on edge devices, faster rendering for expressiveness is now possible through the elusive “collaborative processing”.

Enter Vector Tiles. Map box has defined a vector tile specification that we at Esri have adopted it in our Javascript API, and demonstrated its versatility at the 2015 User Conference. Andrew Turner has a nice writeup about it. And found this nice in-depth paper that analyses the dynamic rendering of vector-based maps with WebGL.

I wanted to know more about it and I learn by doing. So I implemented two projects, a Mapbox Vector Tile encoder and a visualizer as heuristic experiments to be used with the Esri Javascript API. Again, these are experiments and will report on more updates.