Performance

[trusktr]

The following WebGL globe example seems to have a higher/smoother frame rate than Cesium: http://thematicmapping.org/playground/webgl/earth/

Why might this be? Any techniques Cesium can adopt?

[pjcozzi]

Thanks for the note. I didn't turn off browser vsync, but both are pinned at 60 fps for the default view on my MacBook Pro.

The difference is this example is just a sphere with a few textures; Cesium is a full globe engine so, for example, as you zoom in, Cesium loads higher-resolution data.

[trusktr]

I'm noticing the very slight lag just from rotating without zooming. Maybe it's the way the sphere gets drawn? Perhaps the frame rate is still 60fps, but the calculation of the time step is off so that less than 60fps are drawn? (those are just ideas, but it could be any number of things). I definitely notice it. The small lag that I notice seems about the same from desktop to mobile (i.e. the amount of responsiveness isn't diminishing from desktop to mobile). It's hard to describe, but I can notice it with my eyes, a slight jump between each frame, that I don't notice with the other example.

[trusktr]

I just had my friend test on Nexu 6, and he noticed the chop in the graphics too. My gut feeling says it's not a problem with browser rendering since it's just a sphere with some textures on it, and we're not zooming in or out to load different textures, but I could be wrong.

Is there an option to specify how many polygons (or similar) to use?

[pjcozzi]

Closing. We're doing some optimizations as part of #2179.

[trusktr]

Cool, looking forward to it. I was trying these demos on my phone for reference, and they run buttery smooth, so I know cesium should be able to also since it's just a sphere in it's basic form (how WebGLEarth uses it):

• https://goote.ch/7b84b7637c414572b4c75c3c1c742d64.project/
• https://goote.ch/4b6780fba9494226991f6bb89cb80f71.project/
• https://goote.ch/966753b0649e46f192689d44043dc94e.scene/

[trusktr]

Nice, it's been a while, and this issue has since been fixed. The rotation/pan animation is smoooooth.

[lilleyse]

I'm noticing the very slight lag just from rotating without zooming.

Yup, this was fixed in #8811

Fixed what seemed like a kludge in the camera panning code which had the side effect of panning every other frame. Basically panning felt like 30hz while other camera controls felt like 60hz. Panning feels so much smoother now.