Expand description
Exact polyhedral lofts between planar polygon sections (#247).
loft_polygon_stations_exact joins planar polygon sections placed in
their own frames, vertex k of every ring to vertex k of the same
ring at the next section, into a closed B-rep of planar faces: a cap at
the first and at the last section (holes included) and one wall per
ring edge between consecutive sections. It is the exact form of a
linear taper along a straight line, such as a station-placed spine whose
rectangle widens from one station to the next.
Each wall is the ruled surface between two section edges. It is a
plane exactly when its four corners are coplanar; a wall whose fourth
corner leaves the plane of the other three by more than the linear
tolerance is a bilinear patch, which this builder does not make, and is
refused by name (WARPED_WALL), never flattened.
The conventions are the exact extrusion’s: every section’s outer
ring runs counter-clockwise and each hole clockwise about its frame’s
z, which points from one section to the next; the first cap faces
back along it, the last forward, and each wall’s plane normal is the
right-hand normal of its loop a -> b -> d -> c (a, b an edge of one
section, c, d the same edge of the next), which points out of the
material.
Constants§
- WARPED_
WALL - The refusal of a wall whose corners are not coplanar.
Functions§
- loft_
polygon_ stations_ exact - Loft planar polygon sections exactly; see the module documentation.