mourner
commented
5 years ago setFilter is currently a very expensive operation and is indeed problematic when used for animation use cases. Perhaps you could try a different approach — encoding values for different time intervals as feature properties (e.g. one feature would have value1: 12, value2: 15, value3: 20 etc. — and then you would switch between them by doing setPaintProperty('heatmap-weight', ... expression that depends on the right value). This is the approach https://electricitytransition.com is using and it seems to work well.
nerik
agusterodin
(follow up of a conversation with @mikelmaron)
mapbox-gl-js version: 0.54
browser: Chrome and Firefox latest, macOS
Our current map is a combination of Mapbox GL layers for all non-animated layers, and a custom WebGL renderer for animated heatmaps, which is not performing well enough and is a battery drain (because it’s heavily CPU bound).
Steps to Trigger Behavior
See below
Link to Demonstration
On paper, using Mapbox GL heatmap layers would be an ideal solution: not only performance is much better, but also they look way better (and we could remove a huge legacy dependency from our front-end). The problem is that we can't get this to behave nicely with animation (ie repeatedly changing a timestamp filter on a layer). See for yourself: https://codepen.io/nerik8000/pen/rgMdqP?editors=0010
Expected Behavior
When clicking the start button on the top left, the filter value gets updated at each rAF call to display more or less points depending on a timestamp global value. When stopping the animation (stopping updates to filter), Mapbox GL should skip any pending update and display the filtered data that matches what the UI expects, which is the last timestamp.
Actual Behavior
As you can see in the demo, when clicking the stop button, there's seemingly a queue of rendering updates that get executed one by one. This result in a lag of several seconds between the expected value and what's actually visible in the map.
While I understand the performance implications of filtering that many points (several 10s of 1000s in the demo), there should be a mechanism to allow skipping frames to match as closely as possible whatever values are set from outside. The issue here being that the resulting discrepancy makes any numeric statement displayed outside the map wrong (until the animation's final frame).
Thanks for your help.