There is no such thing as a true curve in 3D.
It may still behave as an arc or circle (i.e. stretchy radius) but it is actually made up from many straight edges.
The number of edges is controlled in your Magic Wand settings.
You may also have the magic wand settings to use a tracing method of "Linear Segments" rather than "Best Match" which will give you curves.
Barry.
One of the forum moderators.
Versions 6.5 to 27
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