February 2021 Summaries

Mapbox recently introduced two new features to its Static Images API, enhancing user control over image cropping and viewport settings through the addition of padding and bounding box (bbox) parameters. The padding parameter allows developers to specify padding on each side of an image using one to four integer values, enabling tailored image presentations for various contexts, such as adding visual whitespace or accommodating UI elements. The bbox parameter, on the other hand, enables users to define the entire viewport for a static image request, providing precise control over the rendered area by replacing the auto or center/zoom parameters. This option is particularly useful for setting a specific geographical context, as demonstrated with examples of the Midnattsloppet and Boston Marathon routes, where it allows for better visualization of the mapped area. The combined use of bbox and padding can further refine the image's appearance, offering flexibility in centering overlays and adding context to geographical elements. These new capabilities, stemming from developer feedback, are detailed in the Static Images documentation, and Mapbox encourages users to share their applications of the API on social media.

Amid a snowy winter, outdoor enthusiasts are utilizing tools like Strava, OpenSkiMap, and Traveler Today, which rely on trail data from OpenStreetMap (OSM), a free, community-built map integrated into various mapping platforms including Mapbox. The text explains how developers can create custom ski trail maps using OpenStreetMap data extracts with tools like Overpass Turbo and Mapbox Tiling Service (MTS). It highlights projects such as OpenSkiMap.org and Snow Social, which use OSM data to provide interactive mapping solutions for skiers. The process involves querying OSM data for ski trails, exporting it as GeoJSON, and transforming it into tilesets using MTS, which offers efficient data preprocessing and customization options such as setting zoom extents and filtering attributes. By using a recipe file, developers can optimize large-scale data, ensuring maps are both detailed and efficient. Once transformed, the tileset can be published and integrated into mapping applications, allowing for the creation of customized, interactive maps for various outdoor activities.

Mapbox GL JS v2.1.1 introduces enhancements such as efficient pitched tile loading, improved rendering precision for Chinese, Japanese, and Korean labels, and 3D interaction improvements. The update optimizes tile loading in pitched views by adjusting the horizon line, enhancing performance and reducing memory usage. It also enhances the appearance of CJK labels by introducing local font rendering and doubling the resolution for better clarity. Issues with rendering order during 3D terrain interactions are addressed, allowing consistent layer rendering, while map-aligned labels on 3D terrains are made more legible. The update supports querying features on 3D maps and introduces JavaScript Promises for map events, facilitating a more streamlined use of async/await patterns. Additionally, it resolves a clustering issue at high zoom levels and fixes a race condition related to image expressions, ensuring sprite availability before evaluation. Users can upgrade to v2.1.1 by including the new JavaScript and CSS files from the CDN in their HTML files.

Mapbox 3D introduces a new Camera API that enhances map visualization by allowing developers to increase the map pitch from 60 to 85 degrees, thus revealing the horizon and sky, which can be styled using the new Sky API. This update replaces sky layers with fog as the preferred method for sky styling, offering a range of design effects such as realistic atmospheres, gradients, and simulations of the sun’s position based on geographic location and time of day. The Sky API offers various properties, including sky-opacity and sky-type, which can render either a gradient or an atmospheric sky using a scattering algorithm, allowing for artistic and time-of-day configurations. To optimize performance on lower-end devices, the skybox generation employs a bake-once-reuse approach, using smooth interpolation and temporal dithering to maintain visual continuity. Developers can leverage JavaScript libraries like SunCalc to dynamically adjust sky colors and sun positions, enhancing user experiences based on real-world conditions, and they can integrate these features into their maps through Mapbox Studio, with opportunities to share their creations on social media platforms.

Nextstrain, co-developed by Trevor Bedford of the Fred Hutchinson Cancer Research Institute, is vital in tracking the spread of SARS-CoV-2 by open-sourcing data to enhance epidemiological understanding and public health responses. Bedford's team analyzed vaccine distribution in 2021 and the potential antigenic drift of the virus, suggesting that while the vaccine efficacy remains high, ongoing surveillance of viral mutations is crucial to address potential antigenic changes over time. The research highlights the possibility of SARS-CoV-2 behaving similarly to influenza, necessitating periodic updates to vaccines, although current variants are not expected to significantly impact the 2021 vaccine rollout.

Jonni Walker, a UK-based Cartographer at Mapbox, is known for his stunning design principles and shares insights and tips on implementing these techniques in projects through his Twitter handle, twitter.com/jonni_walker.