Geometric properties

This section covers measuring the geometric properties of a model.

Geometry calculations use model units: volume is measured in cubic units. STL/STEP/3MF exporters interpret source coordinates as millimetres. To obtain physical mass, multiply volume by density in matching units.

Built-in methods

Shape provides methods for querying geometric information.

Center of mass

shape.center() # -> Point3

Volume

shape.mass() # -> Scalar

Example

For a solid, mass() returns volume as a Scalar; center() returns the center of mass as a Point3. .value() obtains a number or coordinate tuple.

import zencad as z

body = z.box(2, 3, 4)
volume = body.mass()
center = body.center()
assert abs(volume.value() - 24) < 1e-7
assert all(abs(a - b) < 1e-7 for a, b in zip(center.value(), (1, 1.5, 2)))

Use inspect for area and aggregate properties of the visible scene, and the bounding box for dimensions.