Customizing vector basemaps

Anyone who has been working in the field of GIS has heard of these sayings: “raster is faster, but vector is corrector” or “raster is faster, but vector is better.” Times have changed when it comes to online maps. Raster is no longer faster, and vector is definitely better.

Better mapping ahead with Vector Tiles!

About a year and a half ago, vector tile basemaps became available in ArcGIS Online. Vector tiles are essentially vector representations of the data being used to create the map. In contrast to the raster basemaps which are pre-rendered, the vector tile basemaps are rendered on the client-side based on a style file that comes with them. There are numerous advantages to vector tiles, including:

1. Vector tile maps are smaller in file size than raster maps, requiring less storage space. A complete raster tile basemap of the world at all standard ArcGIS Online scales requires 20 TB of space. A similar vector tile map requires only 20 GB of file space.
2. Vector tile maps are quicker to draw than raster maps.
3. Vector tile maps are easier and quicker to produce. A vector tile map of the world currently takes about eight hours to produce on a single desktop computer. In comparison, a raster map of the world requires numerous processors many weeks to produce.
4. Vector tile maps appear crisper than raster maps, making them more suitable for high resolution displays.
5. Vector tile maps have rotatable labels. Raster maps do not.
6. Finally, and best of all, vector tile maps are completely customizable. Raster maps, on the other hand, can only be displayed in one style. To create a different style raster map, you would need to re-cache the entire map, a potentially time-consuming job. Different map styles utilize the same map cache; no additional map caching is required.

Customizing the Vector Tile Map

A new vector tile style editor is now available that makes it easy for you to change the style of any existing basemap. You can select any vector tile map style, including the existing Esri produced basemaps such as the streets basemap or the topographic basemap, and you can change the symbology on any of the visible features.

Once you’ve selected a map style, you can edit it in a variety of ways.

Quick Edit allows you to change all the colours on the map quickly without a lot of finesse. If you click on a colour swatch, you can pick the colour you want or enter a hex value for the colour in the adjoining box. This is perfect if you want to quickly create a different style basemap. But if you want to start tweaking the colours and styles of individual features, you’ll need to go deeper.

By selecting the Edit Layer Styles button on the left-hand side of the application, you’ll be able to open all the layers on the map and change each layer style individually. Layers are grouped by theme, and each layer that is used in the map appears in the table of contents. Clicking on a layer will open up a more detailed menu that allows you finer control over how you want that feature to appear.

Here you can specify what zoom levels the feature will appear at, the fill colour and pattern fill along with the outline colour, style and opacity. Changing the style here immediately changes the style in the map. If you are not happy with how it appears, the changes can be cancelled, and it reverts to how it appeared before.

You can also edit the map styles by colour. Clicking on this button will bring up all the colours that are used in the map. Selecting a colour and changing it will change all instances where that colour is used, regardless of the feature.

If you prefer, you can also edit styles by panning and zooming on the main map and clicking a feature. This will bring up the style attributes for that feature that you can then change to meet your preferences.

Once you’re content with the changes you’ve made, you can save the map style and publish it to ArcGIS Online.

These are a couple of tips before you start:

1. Have a look through the already published map styles to see if there is anything that comes close to the look you want. Aside from the usual basemap mainstays such as the topographic, street and grey scale basemap styles, there are several more artistic looking styles. I particularly like the new Charted Territory map style.
   
2. If you’re new to using this edit, select an existing map style that is simple in appearance and displays a minimal number of layers such as one of the grey canvas maps. The topographic basemap style contains many different feature layers, and it can be quite time consuming to wade through and change the styles of all the layers.

The basemap style editor makes it easy to customize the appearance of any basemap and allows the user cartographic control over their online mapping products and presence. Expect to see some interesting new basemaps in the near future!