Atul Kumar (Frontend-Sr. Associate Consultant L2- Frontend Development)

Integrating custom data visualization into a map interface can be challenging but rewarding. Recently, I worked on a project where I rendered interactive layers on Google Maps using Deck.gl in a React application. Leveraging the vis.gl package, I achieved a seamless integration between Google Maps and Deck.gl, enabling rich and performant visualizations.

In this blog, I'll walk you through how I set this up and some of the lessons I learned along the way.

Why Deck.gl and Google Maps?

Before diving into the implementation, let's address why I chose these tools:

• Deck.gl: A powerful WebGL-based framework for visualizing large datasets. It offers out-of-the-box support for layers like scatterplots, heatmaps, GeoJSON, and more.
• Google Maps: A ubiquitous mapping platform with robust APIs and unmatched global map data.

By combining these two, I aimed to leverage Deck.gl's visualization capabilities while maintaining the familiar interface and features of Google Maps.

Rendering Google Maps

import React from 'react';
import {createRoot} from 'react-dom/client';
import {APIProvider, Map} from '@vis.gl/react-google-maps';

const App = () => (
  <APIProvider apiKey={API_KEY}>
    <Map
      style={{width: '100vw', height: '100vh'}}
      defaultCenter={{lat: 22.54992, lng: 0}}
      defaultZoom={3}
      gestureHandling={'greedy'}
      disableDefaultUI={true}
    />
  </APIProvider>
);

const root = createRoot(document.querySelector('#app'));
root.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>
);

Adding Deck.gl Layers

To add layers, I defined them using Deck.gl's API. For example, here's how I rendered a ScatterPolygonLayer:

import {ScatterplotLayer} from '@deck.gl/layers';

const layer = new ScatterplotLayer({
  id: 'bart-stations',
  data: [
    {name: 'Colma', passengers: 4214, coordinates: [-122.466233, 37.684638]},
    {name: 'Civic Center', passengers: 24798, coordinates: [-122.413756,37.779528]},
    // ...
  ],
  stroked: false,
  filled: true,
  getPosition: d => d.coordinates,
  getRadius: d => Math.sqrt(d.passengers),
  getFillColor: [255, 200, 0]
});

Challenges and Optimizations

1. Managing WebGL Contexts

A common issue with WebGL-based libraries is the WebGL context limit. Opening multiple map views simultaneously caused older contexts to be lost. I resolved this by unmounting Deck.gl layers when a tab became inactive and remounting them when the tab regained focus.

2. Handling Large Datasets

For large datasets, I ensured smooth rendering by using Deck.gl's optimizations, such as data filtering and reduced resolution for non-essential features.

3. Custom Interactions

Deck.gl supports custom interactivity, which I integrated using event handlers like onHover and onClick to enhance the user experience.

Final Thoughts

Combining Deck.gl with Google Maps offers immense flexibility for building interactive map-based visualizations. The vis.gl package simplifies the integration process, allowing developers to focus on crafting engaging layers and features. While challenges like managing WebGL contexts can arise, careful planning and best practices make them manageable.

If you're working on a similar project, I hope this guide provides a helpful starting point. The combination of Deck.gl and Google Maps is a powerful duo that unlocks new possibilities for geospatial visualization.

Vis.gl google maps - https://visgl.github.io/react-google-maps/
Deck.gl - https://deck.gl/