Genesis-Embodied-AI/genesis-world · error · ValueError

center must have shape (3,)

Error message

center must have shape (3,)

What it means

A radial force field validates its center argument: np.asarray(center) must have shape exactly (3,). Any other shape raises this ValueError during construction, before the field is added to the scene.

Source

Thrown at genesis/engine/force_fields.py:110

        The direction of the wind. Will be normalized.
    strength: float
        The strength of the wind.
    radius: float
        The radius of the cylinder.
    center: array_like, shape=(3,)
        The center of the cylinder.
    """

    def __init__(self, direction=(1, 0, 0), strength=1.0, radius=1, center=(0, 0, 0)):
        super().__init__()

        direction = np.array(direction)
        if direction.shape != (3,):
            raise ValueError("direction must have shape (3,)")

        center = np.array(center)
        if center.shape != (3,):
            raise ValueError("center must have shape (3,)")

        self._center = center
        self._direction = direction / np.linalg.norm(direction)
        self._strength = strength
        self._radius = radius

        self._direction_qd = qd.Vector(self._direction, dt=gs.qd_float)
        self._center_qd = qd.Vector(self._center, dt=gs.qd_float)
        self._acc_qd = qd.Vector(self._direction * self._strength, dt=gs.qd_float)

    @qd.func
    def _get_acc(self, pos, vel, t, i):
        # distance to the center of the cylinder pointing in the direction of the wind
        dist = (pos - self._center_qd).cross(self._direction_qd).norm()
        acc = self._acc_qd
        if dist > self._radius:
            acc = qd.Vector.zero(gs.qd_float, 3)
        return acc

View on GitHub (pinned to 56e4aa5d82)

Solutions

1. Pass a flat 3-element position: center=[0.5, 0, 1.0]
2. Flatten or reshape incoming arrays to (3,) before passing
3. Add a shape assertion in config-loading code for field positions

Example fix

# before
field = RadialForceField(strength=1.0, radius=1, center=np.array([[0], [0], [1]]))
# after
field = RadialForceField(strength=1.0, radius=1, center=[0, 0, 1])

center = np.ravel(center)
assert center.shape == (3,), 'center must be a flat 3-vector'
field = RadialForceField(strength=1.0, radius=1, center=center)

def is_vec3(x) -> bool:
    return np.asarray(x).shape == (3,)

try:
    field = RadialForceField(center=center, radius=1)
except ValueError as e:
    raise ValueError(f'invalid center {center!r}: {e}') from e

When it happens

Trigger: Passing center=[0,0] or [0,0,0,0], a scalar, or a (3,1)/(1,3) array to RadialForceField(center=...).

Common situations: Placing an attractor/repeller field at a 2D point from a top-down planner, loading center coordinates from JSON with a missing component, or passing a column vector.

Related errors

• direction must have shape (3,)
• position must have shape (3,)
• probe_arc_spacing must be positive, got {arc_spacing}
• Python module 'uipc' is required by IPCCoupler but is not in
• `morph` in hybrid entity should be either URDF or Mesh

AI-assisted analysis of Genesis-Embodied-AI/genesis-world@56e4aa5d82 (2026-08-28). Data as JSON: /api/errors/90388c8ae536f5e9. Report an issue: GitHub.