CIrcle segments are useful for things like tires, heads, bubbles, and the like, but since they are a special kind of line segment, there are some built in limitations summarized in the table below:
||You can't distort a circle, but you can stretch it - doing so makes the circle increase its diameter.
||You can't add any nodes to a circle segment, but deleting the "end" pivot node for a circle will delete the circle from the figure it was attached to.
||You can't have a circle that has a width that is greater than its length (see "Circle Width" below), or in any event greater than 255 pixels in width.
In Stykz, increasing the width (thickness) of a circle causes the width to expand evenly on either side of the node until the width of the circle is equal to the length of the circle (the distance from the node on one side of the circle to the node on the other side of the circle:
As a result, the rule in Stykz is: The width of a circle can never be greater than its length.
PIVOT COMPATIBILITY NOTE: Pivot has a different way of handling circle segments and can allow the width (thickness) of a circle to be larger than its length. So if you try to import a Pivot .stk file that contains circles with a line width greater than its length, you will get a warning dialog (see Notes on .stk Compatibility for an explanation of this).