pchandler.scalar_fields.scalar_field_manager

ScalarFieldManager: container for the per-point scalar fields of a PointCloudData.

Module Attributes

`SF_T`	Base scalar field TypeAlias
`SFLikeT`	Scalar Field like TypeAlias, also supporting other arrays of similar shape
`RGBLikeT`	RGB like TypeAlias
`NormalLikeT`	Normal like TypeAlias
`SFMLikeT`	ScalarFieldManager like dict TypeAlias

Classes

ScalarFieldManager

Manages scalar fields associated with a point cloud.

class pchandler.scalar_fields.scalar_field_manager.ScalarFieldManager

Bases: object

Manages scalar fields associated with a point cloud.

Contains mechanisms for adding, changing and removing scalar fields as well as validating lengths with respect to a parent point cloud object.

Parameters:

fields (dict[str, ScalarField|NormalFields|RGBFields])
_parent (weakref.ReferenceType[PointCloudData] | None)

__init__(fields=None, *, parent=None)

Initialise the scalar field manager.

Ensures all fields passed are converted to ScalarField (or the appropriate RGBFields / NormalFields) objects. If a parent point cloud is provided, it is stored as a weakref and scalar-field lengths will be validated against it.

Parameters:

fields (dict[str, ScalarField | NormalFields | RGBFields | np.ndarray] | ScalarFieldManager | None) – Initial scalar fields, either as raw dict, another manager, or None (empty manager).
parent (PointCloudData, optional) – Owning point cloud; stored as a weakref so that length validation can be performed.

fields: dict[str, SF_T]

validate_lengths()

Check that every scalar field’s length matches the parent point cloud’s point count.

Raises:: ValueError – If any scalar field’s length differs from the parent point count.

keys()

Return the scalar field names stored in the manager.

Return type:: KeysView[str]

values()

Return the scalar field values stored in the manager.

Return type:: ValuesView[SF_T]

items()

Return the scalar field names and values stored in the manager.

Return type:: ItemsView[str, SF_T]

property parent: PointCloudData | None

Return the parent point cloud object.

Return type:: PointCloudData | None

property shape: tuple[int, int]

Return the shape of the scalar field manager.

The shape will be in the form (num_points, num_fields).

Return type:: tuple[int, int]

property num_points: int

Return the number of points in the parent point cloud, or -1 if no parent is set.

Returns:: Parent point count, or -1.
Return type:: int

property rgb: RGBFields | None

Get the RGB fields.

Return type:: RGBFields | None

property normals: NormalFields | None

Get the normals fields.

Return type:: NormalFields | None

property intensity: ScalarField | None

Get the intensity field, or None if not set.

Returns:: Intensity field, or None.
Return type:: ScalarField | None

property reflectance: ScalarField | None

Get the reflectance field.

Return type:: ScalarField | None

sample(mask)

Sample the scalar fields based on a mask.

Parameters:: mask (IndexLike) – The mask corresponds to indexing the rows or points in the parent point cloud.
Return type:: ScalarFieldManager

reduce(mask)

Reduce every scalar field in place to the rows selected by mask.

Parameters:: mask (IndexLike) – The mask corresponds to indexing the rows or points in the parent point cloud.

extract(mask)

Return a new manager carrying the selected rows; also reduces self to the complement.

Parameters:: mask (IndexLike) – The mask corresponds to indexing the rows or points in the parent point cloud.
Returns:: New manager containing the rows selected by mask.
Return type:: ScalarFieldManager

add_field(sf_field)

Add a new scalar field to the manager (keyed by sf_field.name).

Parameters:: sf_field (SF_T) – Scalar field to add.

remove_field(field_name)

Remove a scalar field from the manager by name.

Parameters:: field_name (LowerStr) – Name of the field to remove.

create_field(name, data)

Create a scalar field from a name and an array, then add it to the manager.

Supports Array_Nx3_T for the creation of RGB or Normals fields.

Parameters:

name (str) – Name of the new field.
data (VectorT | Array_Nx3_T) – Field data.

classmethod merge(scalar_field_managers)

Merge a list of scalar-field managers, keeping only the fields they all share.

Parameters:: scalar_field_managers (Iterable[ScalarFieldManager]) – Managers to merge.
Returns:: New manager containing every commonly-named scalar field concatenated along axis 0.
Return type:: ScalarFieldManager
Raises:: ValueError – If scalar_field_managers is empty.

as_struct_array()

Return the scalar fields packed into a single numpy structured array.