Cesium CPU usage

We talked offline about this yesterday so I figured I’d write up an issue for it. The default render loop in CesiumWidget and Viewer currently render at 60fps no matter what. Setting the targetFrameRate property can lower it, but is only useful in limited cases.

What we really want to do is only render if we actually need to. This will reduce CPU load and also help with battery life (for devices where that’s an issue). Here’s the “rules” @kring previously came up with.

We don’t render unless:

1. The simulation time has changed,
2. The user interacts via the mouse, etc.,
3. A property of something in the scene has changed, or
4. New data is loaded (such as terrain tiles)

[ggetz]

I’ve posted our initial plans to tackle this issue on the forum here: https://groups.google.com/forum/#!topic/cesium-dev/E2XXB44zWew

Please give us your feedback, including any of your thoughts or use cases there!

[wallw-teal]

@chris-cooper We have been extending ol3-cesium’s AutoRenderLoop. It still isn’t perfect, but it is much better than before.