Hi,
I'm trying to draw circles using polylines, as also presented in the
circles & elliposes sandcastle demo:
http://cesium.agi.com/Cesium/Apps/Sandcastle/?src=Circles%20and%20Ellipses.html
what I experience is, and this is also present in the sandcastle demo,
is that the circle is not 'closed' - on the southern side there is a gap
in the circle. this is despite the fact that in
Shapes.computeCircleBoundary, there is a call to push the first position
to the end of the array. and even if I try to do the same myself
afterwards, I get the same results. and if I investigate the first and
last points in the positions array, they are the very same positions.
despite this, there is a gap in the circle 
moreover, I'd like to inquire about the unit of measurement of the width
of the polyline. it seems to be constant in terms of width compared to
the viewport. that is, if I zoom out the width stays the same - but the
radius is (visually) decreased! this means that eventually the width can
be greater than the visual radius of the circle, which brings sideeffects
I wonder if it is possible to specify a width in terms of 'real-world
width'?
Akos