To generate a circle using surface data:
Click the Surface mode icon ().
Position the mouse pointer either outside or inside the desired circle.
Click once on a surface near the circle.
The BASICSCAN dialog box (Insert | Scan | Circle) displays the X, Y, and Z center point, diameter, and vectors for the circle from the selected CAD data.
The CutVec is taken from the plane in which the circles lies. This comes from the CAD model.
The InitVec is arbitrarily
set from the CAD model. If the circle lies in the Y or Z plane, it
is -X if it is an inner circle. It is +X if it is an outer circle.
If the circle lies in the X plane, it is +Z if it is an inner circle.
It is -Z if it is an outer circle.
For more information about the BASICSCAN dialog box and the circle basic scan, see "Performing a Circle Basic Scan".