Topology-dependent operations

Some operations require a particular topological element of a model. In an interactive CAD system, you can select it with the mouse. Scripted CAD needs another approach. One ZenCad option is the "nearest point" method: pass a point instead of the element, and the closest element is selected.

For explicit selection of edges and faces, use topology selectors.

Fillet

Rounds a shape: edges for a solid, vertices for a planar shape. Specify a radius r and an array of reference points refs. refs=None selects all elements.

fillet(model, radius, referencedPoints)
fillet(model, radius)
model.fillet(radius, referencedPoints)
model.fillet(radius)

Chamfer

Chamfers a body. Unlike fillet, it applies only to solids. r is the distance from the edge to the chamfer boundary; refs is an array of reference points. refs=None selects all elements.

chamfer(model, radius, referencedPoints)

Face draft

draft tilts selected faces relative to a neutral plane—for example, to help remove a part from a mold. A positive angle removes material along the pull direction; a negative angle adds it. The neutral plane remains fixed.

The default direction is +Z, with the neutral plane through the origin and perpendicular to that direction. neutral also accepts a planar face or an (origin, normal) pair. Selected faces must belong to the original body and be planar, cylindrical or conical.

body = box(20)
side_faces = body.faces().filter_by_position(Axis.Z, 10)

narrower = draft(body, side_faces, deg(5))
wider = draft(body, side_faces, deg(-5))
midplane = draft(
    body,
    side_faces,
    deg(5),
    neutral=((0, 0, 10), (0, 0, 1)),
)

Thicksolid

Creates a thin-walled solid from a prototype shp. refs contains points nearest to the faces to remove. Wall thickness t is measured outward when positive and inward when negative.

thicksolid(model, t=thickness, refs=referencedPoints)

Result types and element selection

fillet() and chamfer() return Shape; inspect the contents with faces() and solids(). Even a result containing one solid retains the Shape wrapper.

For nearest-element selection, pass a list of point3(...) or Vertex objects. For explicit edge selection, pass a list of Edge objects from the original body. Edges and points cannot be mixed. Plain coordinate tuples in the reference list are not supported; use point3. None selects all elements, while an empty list raises ValueError. Edges from another model are rejected. For filleting a planar face, select vertices or points.