SimpleCADAPI is OCP-native at runtime: public geometry objects are thin Python wrappers around OpenCascade/OCP shapes exposed through the .wrapped attribute. The package provides functional modeling operations, expression parameters, QL selectors, and replayable model JSON.

Core Classes Overview

Coordinate and tagging utilities

CoordinateSystem

A right-handed 3D coordinate system for local modeling contexts and point/vector transformation.

SimpleWorkplane

A context manager for temporarily modeling in a local coordinate system.

TaggedMixin

Shared tag and metadata behavior for geometry wrappers.

Geometry wrappers

Vertex

A 0D topology wrapper with coordinate queries.

Edge

A 1D topology wrapper for lines, arcs, circles, splines, and other curve edges.

Wire

A connected path made from edges. Wires may be open or closed.

Face

A bounded surface with an outer wire and optional inner wires.

Solid

A closed 3D body with volume, faces, edges, tags, and metadata.

Compound

A collection wrapper for multiple geometry objects.

Product semantics roadmap

Part and Assembly Development Plan

Planned single-body Part, material assignment, component placement, and Assembly semantics layered above the current topology/geometry and operation graph model.

Relationship Diagram

TaggedMixin
├── Vertex (0D)
├── Edge (1D)
├── Wire (1D)  ← composed of edges
├── Face (2D)  ← bounded by wires
├── Solid (3D) ← bounded by faces
└── Compound   ← collection of shapes

CoordinateSystem ← independent utility
SimpleWorkplane  ← local modeling context

Design Principles

Shape-first API: users work with Vertex, Edge, Wire, Face, and Solid, not graph nodes.
Functional modeling style: public operations return new geometry values, e.g. make_box_rsolid(...), cut_rsolid(...), fillet_rsolid(...).
OCP-native runtime: geometry construction, topology traversal, properties, booleans, transforms, and export use OCP/OpenCascade helpers.
Replayable graph workflows: @scad.model owns one GraphSession and returns a ModelResult; @scad.requires_session composes child builders, and scad.capture_result() selects canonical output nodes for replay and export.
Tags and metadata: tags are useful for lightweight semantics; structured numeric facts should be stored in metadata such as metadata["geo"].
Indexed topology access: use plural methods such as get_edges() and get_faces() for enumeration, and pass an index to the same getter, such as get_edges(index) or get_faces(index), for intentional indexed picks that should become graph selection nodes.

Basic Usage

import simplecadapi as scad

with scad.SimpleWorkplane(origin=(0, 0, 0)):
    box = scad.make_box_rsolid(width=5, height=3, depth=2)

scad.apply_tag(shape=box, tag="role.bracket")
box.set_metadata("material", "6061-T6")
box.auto_tag_faces("box")

top_faces = [
    face for face in box.get_faces()
    if "face.top" in scad.list_tags(shape=face)
]
print(len(top_faces))

Replayable Model JSON

import simplecadapi as scad

@scad.model(graph_id="drilled_block")
def build_model():
    body = scad.make_box_rsolid(width=10, height=10, depth=4)
    hole = scad.make_cylinder_rsolid(
        radius=1.5, height=8, bottom_face_center=(0, 0, -2)
    )
    part = scad.cut_rsolid(body, hole)
    scad.capture_result(value=part)
    return part

result = build_model()
rebuilt = result.replay()
print(len(rebuilt))

SimpleCAD API Core Classes Documentation