There seems to be a maximum pixelSize of points of about 60px but I can't find this documented anywhere. Is there a reason for this restriction? thanks
This is probably a GPU limitation on your machine. Check Aliased Point Size Range on http://webglreport.com/.
This is what I see when running the code:
Thanks, that's exactly it.
Aliased Point Size Range: [1, 63.375]
I see now that it's referenced in a open issue:
https://github.com/AnalyticalGraphicsInc/cesium/issues/3118
It's only a 3yr old macbook pro so i'm a little surprised that it's a hardware limitation