Module build 

Building topology from geometry.

One level above Model’s raw builders: these take geometry, derive the topology it implies, check the invariants that need geometry to check, and report history.

What “checked” means here

Model::add_wire verifies that its children are edges. That is all it can do, because it has no geometry. make_wire additionally verifies that consecutive edges actually meet, which is the property that makes a wire a connected path rather than a bag of edges, and which every algorithm downstream assumes without checking. A wire whose edges do not join produces a face with a gap in its boundary, and the first thing to notice is usually a boolean, several operations later.

Modules

roles

Roles a builder assigns, so a rebuild can match entities up.

Functions

attach_pcurve

Attach a pcurve to an edge, describing it in a surface’s parameter space.

attach_seam

Attach a seam representation to an edge: one pcurve per side of a closed surface’s join.

chain_wire_branches

Put a face’s wires on one branch of a periodic chart.

edge_vertices

The vertices an edge runs between, in the direction it is traversed.

find_plane

The plane a shape lies in, if it lies in one.

is_shell_closed

Whether every edge in a shell is shared by exactly two faces.

is_wire_closed

Whether a wire’s last edge returns to its first edge’s start.

make_apex_band

Build the face of a revolution cap: one closed ring belting a cone, with the apex the file never wrote synthesised as the degenerate ring the band needs.

make_band_between

Build the face of a band between two closed rings that need not be circles, each with a caller-supplied chart image.

make_compound

Build a compound from any shapes, with history.

make_compsolid

Build a shell from faces.

make_edge

Build an edge on curve, bounded by its own endpoints.

make_edge_between

Build an edge between two existing vertices, on curve.

make_face

Build a face on surface, bounded by wires.

make_face_on

Build a face on a surface the model already holds.

make_face_with_pcurves

Build a face on surface from per-wire edge lists, attaching an exact same-parameter pcurve to every edge.

make_natural_face

Build a face covering the whole of surface, with no trimming.

make_polygon

Build a wire of straight segments through a sequence of points.

make_revolution_band

Build the face of a revolution band: two closed rings joined by a synthesised seam, pcurves attached window-coherently.

make_shell

Build a shell from faces.

make_solid

Build a solid from shells.

make_vertex

Add a vertex at point.

make_wire

Build a wire from edges that meet end to end.

rings_are_parallels

Whether two closed ring edges are parallels of surface, so that make_revolution_band can build a band between them. A reader asks this first: a periodic face bounded by two closed circles that are not parallels (a button head’s rims, square to the screw on a sphere whose chart runs along z) is a legitimate face on its own bounds, not a band missing its seam, and deserves no warning.

surface_iso_u_curve

The surface’s u = at iso-curve, parameterized by v exactly.

trimmed_where_bare

Give every edge of face that has no trim on the face’s surface its exact one, where a closed form exists: a profile built from bare curves becomes a face a sweep can keep as an end.