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transform.py

rerun.log.transform

Methods for logging transforms on entity paths.

Learn more about transforms in the manual

def log_view_coordinates(entity_path, *, xyz='', up='', right_handed=None, timeless=False, recording=None)

Log the view coordinates for an entity.

Each entity defines its own coordinate system, called a space. By logging view coordinates you can give semantic meaning to the XYZ axes of the space.

This is particularly useful for 3D spaces, to set the up-axis.

For pinhole entities this will control the direction of the camera frustum. You should use rerun.log_pinhole(…, camera_xyz=…) for this instead, and read the documentation there.

For full control, set the xyz parameter to a three-letter acronym (xyz="RDF"). Each letter represents:

  • R: Right
  • L: Left
  • U: Up
  • D: Down
  • F: Forward
  • B: Back

Some of the most common are:

  • "RDF": X=Right Y=Down Z=Forward (right-handed)
  • "RUB" X=Right Y=Up Z=Back (right-handed)
  • "RDB": X=Right Y=Down Z=Back (left-handed)
  • "RUF": X=Right Y=Up Z=Forward (left-handed)

Currently Rerun only supports right-handed coordinate systems.

Example
rerun.log_view_coordinates("world/camera/image", xyz="RUB")

For world-coordinates it's often convenient to just specify an up-axis. You can do so by using the up-parameter (where up is one of "+X", "-X", "+Y", "-Y", "+Z", "-Z"):

rerun.log_view_coordinates("world", up="+Z", right_handed=True, timeless=True)
rerun.log_view_coordinates("world", up="-Y", right_handed=False, timeless=True)

Parameters:

Name Type Description Default
entity_path str

Path in the space hierarchy where the view coordinate will be set.

 required
xyz str

Three-letter acronym for the view coordinate axes.

 ''
up str

Which axis is up? One of "+X", "-X", "+Y", "-Y", "+Z", "-Z".

 ''
right_handed bool | None

If True, the coordinate system is right-handed. If False, it is left-handed.

 None
timeless bool

If true, the view coordinates will be timeless (default: False).

 False
recording RecordingStream | None

Specifies the rerun.RecordingStream to use. If left unspecified, defaults to the current active data recording, if there is one. See also: rerun.init, rerun.set_global_data_recording.

 None

def log_unknown_transform(entity_path, timeless=False, recording=None)

Log that this entity is NOT in the same space as the parent, but you do not (yet) know how they relate.

Parameters:

Name Type Description Default
entity_path str

The path of the affected entity.

 required

timeless: Log the data as timeless.

recording: Specifies the rerun.RecordingStream to use. If left unspecified, defaults to the current active data recording, if there is one. See also: rerun.init, rerun.set_global_data_recording.

def log_disconnected_space(entity_path, timeless=False, recording=None)

Log that this entity is NOT in the same space as the parent.

This is useful for specifying that a subgraph is independent of the rest of the scene. If a transform or pinhole is logged on the same path, this component will be ignored.

Parameters:

Name Type Description Default
entity_path str

The path of the affected entity.

 required

timeless: Log the data as timeless.

recording: Specifies the rerun.RecordingStream to use. If left unspecified, defaults to the current active data recording, if there is one. See also: rerun.init, rerun.set_global_data_recording.

def log_transform3d(entity_path, transform, *, from_parent=False, timeless=False, recording=None)

Log an (affine) 3D transform between this entity and the parent.

If from_parent is set to True, the transformation is from the parent to the space of the entity_path, otherwise it is from the child to the parent.

Note that new transforms replace previous, i.e. if you call this function several times on the same path, each new transform will replace the previous one and does not combine with it.

Examples:

# Log translation only.
rr.log_transform3d("transform_test/translation", rr.Translation3D((2, 1, 3)))

# Log scale along the x axis only.
rr.log_transform3d("transform_test/x_scaled", rr.Scale3D((3, 1, 1)))

# Log a rotation around the z axis.
rr.log_transform3d("transform_test/z_rotated_object", rr.RotationAxisAngle((0, 0, 1), degrees=20))

# Log scale followed by translation along the Y-axis.
rr.log_transform3d(
    "transform_test/scaled_and_translated_object", rr.TranslationRotationScale3D([0.0, 1.0, 0.0], scale=2)
)

# Log translation + rotation, also called a rigid transform.
rr.log_transform3d("transform_test/rigid3", rr.Rigid3D([1, 2, 3], rr.RotationAxisAngle((0, 1, 0), radians=1.57)))

# Log translation, rotation & scale all at once.
rr.log_transform3d(
    "transform_test/transformed",
    rr.TranslationRotationScale3D(
        translation=[0, 1, 5],
        rotation=rr.RotationAxisAngle((0, 0, 1), degrees=20),
        scale=2,
    ),
)

Parameters:

Name Type Description Default
entity_path str

Path of the child space in the space hierarchy.

 required
transform TranslationAndMat3 | TranslationRotationScale3D | RotationAxisAngle | Translation3D | Scale3D | Quaternion | Rigid3D

Instance of a rerun data class that describes a three dimensional transform. One of: * TranslationAndMat3 * TranslationRotationScale3D * Rigid3D * RotationAxisAngle * Translation3D * Quaternion * Scale3D

 required
from_parent bool

If True, the transform is from the parent to the child, otherwise it is from the child to the parent.

 False
timeless bool

If true, the transform will be timeless (default: False).

 False
recording RecordingStream | None

Specifies the rerun.RecordingStream to use. If left unspecified, defaults to the current active data recording, if there is one. See also: rerun.init, rerun.set_global_data_recording.

 None

def log_rigid3(entity_path, *, parent_from_child=None, child_from_parent=None, xyz='', timeless=False, recording=None)

Log a proper rigid 3D transform between this entity and the parent (deprecated).

Set either parent_from_child or child_from_parent to a tuple of (translation_xyz, quat_xyzw).

Note: This function is deprecated. Use rerun.log_transform3d instead.

Parent-from-child

Also known as pose (e.g. camera extrinsics).

The translation is the position of the entity in the parent space. The resulting transform from child to parent corresponds to taking a point in the child space, rotating it by the given rotations, and then translating it by the given translation:

point_parent = translation + quat * point_child * quat*

Example
t = 0.0
translation = [math.sin(t), math.cos(t), 0.0] # circle around origin
rotation = [0.5, 0.0, 0.0, np.sin(np.pi/3)] # 60 degrees around x-axis
rerun.log_rigid3("sun/planet", parent_from_child=(translation, rotation))

Parameters:

Name Type Description Default
entity_path str

Path of the child space in the space hierarchy.

 required
parent_from_child tuple[npt.ArrayLike, npt.ArrayLike] | None

A tuple of (translation_xyz, quat_xyzw) mapping points in the child space to the parent space.

 None
child_from_parent tuple[npt.ArrayLike, npt.ArrayLike] | None

the inverse of parent_from_child

 None
xyz str

Optionally set the view coordinates of this entity, e.g. to RDF for X=Right, Y=Down, Z=Forward. This is a convenience for also calling log_view_coordinates.

 ''
timeless bool

If true, the transform will be timeless (default: False).

 False
recording RecordingStream | None

Specifies the rerun.RecordingStream to use. If left unspecified, defaults to the current active data recording, if there is one. See also: rerun.init, rerun.set_global_data_recording.

 None