secant_tolerance
The secant tolerance is a global attribute on the <xcsg> root tag defining the default requirement for precision of curved edges or surfaces in the model. It expresses the maximum allowable distance from a straight secant facet to the true curve or curved surface. The tolerance value can be used to automatically calculate the discretization of an object such as a circle or cylinder. In the current version of the file format, it is a global value.
XML syntax for basic circle primitive (2d)
<?xml version="1.0" encoding="utf-8"?>
<xcsg version="1.0" secant_tolerance="0.01">
.... contents ...
</xcsg>
