Primitive Torus

Status: Implemented

Primitive Torus creates an exact analytic torus — full or partial — swept about the +Y axis through the origin.

Walkthrough

Recorded from the running app by BREP_mcp/tests/videos/primitive-torus.json; regenerate every walkthrough with ./build.sh docs-videos.

Inputs

• id (string, default null) – names the history entry, the solid and its faces.
• majorRadius (number, default 10) – distance from the centre to the tube's centreline (R), taken as a magnitude.
• tubeRadius (number, default 2) – tube radius (r), taken as a magnitude.
• arc (number, default 360) – sweep angle in degrees, in [-360, 360].
• transform (transform, default position [0, 0, 0], rotation [0, 0, 0], scale [1, 1, 1]) – placement baked into the solid before the boolean.
• boolean (boolean_operation, default operation NONE with no targets and mergeCoplanarFaces: true) – optional union / subtract / intersect after creation.

Behaviour

• An arc of 0, a missing or null value, or an expression that evaluates to a non-finite number falls back to a full turn, not to a degenerate partial one. A value that is not a number or an expression string is an error.
• The magnitude of arc is clamped to [1e-6, 360] and drives the geometry. A negative arc reverses the sweep direction: the positive-arc solid is spun a half turn about X onto the opposite side.
• A full torus is a single analytic face named {id}_Side; the solid itself is named {id}.
• A partial torus has six faces: four revolved tube quarters initially stamped {id}_Side and disambiguated on registration as {id}_Side[0] through [3], plus the start and end caps {id}_Cap0 and {id}_Cap1.
• Never offered by the selection context bar — it takes no references.

Limitations

• A full torus requires a positive tube radius smaller than the major radius.