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novaphy.UrdfInertial

URDF <inertial> block: mass, inertia tensor, and the frame in which they are expressed. Mirrors the <inertial> schema in URDF 1.0.

Attributes

Attribute Description
origin Transform placing the inertia frame relative to the parent link.
mass Body mass [kg].
inertia 3 × 3 inertia tensor expressed in the origin frame [kg · m²].

Example

import numpy as np
import novaphy

inertial = novaphy.UrdfInertial()
inertial.origin = novaphy.Transform()
inertial.mass = 1.5
inertial.inertia = np.diag([0.01, 0.01, 0.01]).astype(np.float32)

Notes

  • inertia is stored as a full 3 × 3 matrix; URDF's six-component representation is unrolled on parse so downstream code can call inertia @ omega directly.
  • The link-local inertia consumed by RigidBody is computed by the scene builder using origin; if you bypass the builder, remember to transform inertia into the link's COM frame yourself.

See Also