VTube v1.4

There is no single intersection point for 180 degree bends - so they require special handling by automatically splitting the bend into two sequential bends.

The image on the right shows two parallel straights that form a 180 degree bend. The built-in logic handles the creation of the two intersection points and splitting of the bend into two 90 degree bends with a zero straight.

VTube now no longer tries to forms straights with a practical length of zero. They are omitted from the solid model created.