Why is CPU usage so high on idle tab?

CesiumJS
1

I’m experiencing a large jump in CPU usage when Cesium is left open on Chrome, even if I’m not doing anything. I go from about 2-3% to about 50% CPU usage. Is there a way to make this not happen?

It might be helpful to mention that I have no need or usage for any of the time features such as clock or timeline, which is my suspicion as to why it is so high. But I’m setting timeline: false on my Cesium Viewer, so are there other settings I can disable?

2

A couple more things I should mention:

  • This is with no data on the map, just the viewer
  • I don’t experience this issue with WebGL Earth
3

Hi Cody,

We’re aware of this and have an issue opened for reducing CPU usage in Cesium here: https://github.com/AnalyticalGraphicsInc/cesium/issues/1865

Please contribute to the discussion there if you have any input, we’d appreciate it!

Thanks,

Gabby

4

Cesium, by default, renders constantly at a target framerate (like a game). This is terrible for CPU usage and subsequently your battery. However, it is possible to make a custom render loop for Cesium that only renders when something changes. The ol-cesium project has a fairly good one in their olcs.AutoRenderLoop class. We used a slight mixin on its notifyRepaintRequired function to make it ignore mouse move events without a button being down. Whenever data changes we fire an event on a global dispatcher which, in turn, calls that function.