Good question and the simple answer is the mathematics engine in VCW is pretty clever and automatically calculates a constantly changing 3D center-line between any combinations of vector boundaries. This algorithm is key to the VCarving process and takes care of even the most complicated of designs.
Imagine the letter ‘T’ with the cutting edges of a V-Bit cutter resting on the outer edges of the vertical lines. The tip of the cutter will automatically drop to the middle point inside the letter to a depth that depends upon the width of the letter and the angle of the cutter. Where, the tip of a pointed cutter such as a 60’ included angle will drop deeper than a 90’ included angle cutter.
Taking this a step further. Where the gap between vectors changes - gets wider or narrower, the depth of cut will also change and VCW calculates the constantly changing points to create a precise, flowing toolpath.
The math gets significantly harder for more complicated shapes and combinations of vectors.
The diagram below tries to show what I mean using an example where the gap between the vertical and horizontal regions is constant, but changes in the corners and also where the 2 bars meet.
Hope this makes sense?