LoopStructural.datatypes.BoundingBox

class LoopStructural.datatypes.BoundingBox(origin: ndarray | None = None, maximum: ndarray | None = None, global_origin: ndarray | None = None, global_maximum: ndarray | None = None, nsteps: ndarray | None = None, step_vector: ndarray | None = None, dimensions: int | None = 3)

Bases: object

A bounding box for a model, defined by the origin, maximum and number of steps in each direction

Parameters:

• dimensions (int, optional) – _description_, by default 3

• origin (Optional[np.ndarray], optional) – _description_, by default None

• maximum (Optional[np.ndarray], optional) – _description_, by default None

• nsteps (Optional[np.ndarray], optional) – _description_, by default None

__init__(origin: ndarray | None = None, maximum: ndarray | None = None, global_origin: ndarray | None = None, global_maximum: ndarray | None = None, nsteps: ndarray | None = None, step_vector: ndarray | None = None, dimensions: int | None = 3)

A bounding box for a model, defined by the origin, maximum and number of steps in each direction

Parameters:

• dimensions (int, optional) – _description_, by default 3

• origin (Optional[np.ndarray], optional) – _description_, by default None

• maximum (Optional[np.ndarray], optional) – _description_, by default None

• nsteps (Optional[np.ndarray], optional) – _description_, by default None

Methods

__init__([origin, maximum, global_origin, ...])	A bounding box for a model, defined by the origin, maximum and number of steps in each direction
cell_centres([order])	Get the cell centres of a regular grid
fit(locations[, local_coordinate])	Initialise the bounding box from a set of points.
from_dict(data)	Create a bounding box from a dictionary
get_value(name)
is_inside(xyz)
matrix([normalise])	Get the transformation matrix from local to global coordinates
project(xyz[, inplace])	Project a point into the bounding box
regular_grid([nsteps, shuffle, order, local])	Get the grid of points from the bounding box
reproject(xyz[, inplace])	Reproject a point from the bounding box to the global space
scale_by_projection_factor(value)
structured_grid([cell_data, vertex_data, name])
to_dict()	Export the defining characteristics of the bounding box to a dictionary for json serialisation
vtk()	Export the model as a pyvista RectilinearGrid
with_buffer([buffer])	Create a new bounding box with a buffer around the existing bounding box

Attributes

bb	Get a numpy array containing origin and maximum coordinates.
corners	Returns the corners of the bounding box in local coordinates
corners_global	Returns the corners of the bounding box in the original space
global_maximum	Get the global maximum coordinates of the bounding box.
global_origin	Get the global origin of the bounding box.
length
maximum	Get the maximum coordinates of the bounding box.
nelements	Get the total number of elements in the bounding box.
origin	Get the origin coordinates of the bounding box.
step_vector
valid	Check if the bounding box has valid origin and maximum values.
volume	Calculate the volume of the bounding box.

property bb

Get a numpy array containing origin and maximum coordinates.

Returns:

np.ndarray – Array with shape (2, n_dimensions) containing [origin, maximum]

cell_centres(order: str = 'F') → ndarray

Get the cell centres of a regular grid

Parameters:

order (str, optional) – order of the grid, by default “C”

Returns:

np.ndarray – array of cell centres

property corners: ndarray

Returns the corners of the bounding box in local coordinates

Returns:

np.ndarray – array of corners in clockwise order

property corners_global: ndarray

Returns the corners of the bounding box in the original space

Returns:

np.ndarray – corners of the bounding box

fit(locations: ndarray, local_coordinate: bool = False) → BoundingBox

Initialise the bounding box from a set of points.

Parameters:

• locations (np.ndarray) – xyz locations of the points to fit the bbox

• local_coordinate (bool, optional) – whether to set the origin to [0,0,0], by default False

Returns:

BoundingBox – A reference to the bounding box object, note this is not a new bounding box it updates the current one in place.

Raises:

LoopValueError – _description_

classmethod from_dict(data: dict) → BoundingBox

Create a bounding box from a dictionary

Parameters:

data (dict) – dictionary with origin, maximum and nsteps

Returns:

BoundingBox – bounding box object

property global_maximum

Get the global maximum coordinates of the bounding box.

Returns:

np.ndarray – The global maximum coordinates (local maximum + global origin)

property global_origin

Get the global origin of the bounding box.

Returns:

np.ndarray – The global origin coordinates

matrix(normalise: bool = False) → ndarray

Get the transformation matrix from local to global coordinates

Returns:

np.ndarray – 4x4 transformation matrix

property maximum: ndarray

Get the maximum coordinates of the bounding box.

Returns:

np.ndarray – Maximum coordinates

Raises:

LoopValueError – If the maximum is not set

property nelements

Get the total number of elements in the bounding box.

Returns:

int – Total number of elements (product of nsteps)

property origin: ndarray

Get the origin coordinates of the bounding box.

Returns:

np.ndarray – Origin coordinates

Raises:

LoopValueError – If the origin is not set

project(xyz, inplace=False)

Project a point into the bounding box

Parameters:

• xyz (np.ndarray) – point to project

• inplace (bool, optional) – Whether to modify the input array in place, by default False

Returns:

np.ndarray – projected point

regular_grid(nsteps: list | ndarray | None = None, shuffle: bool = False, order: str = 'F', local: bool = True) → ndarray

Get the grid of points from the bounding box

Parameters:

• nsteps (Optional[Union[list, np.ndarray]], optional) – number of steps, by default None uses self.nsteps

• shuffle (bool, optional) – Whether to return points in order or random, by default False

• order (str, optional) – when flattening using numpy “C” or “F”, by default “C”

• local (bool, optional) – Whether to return the points in the local coordinate system of global , by default True

Returns:

np.ndarray – numpy array N,3 of the points

reproject(xyz, inplace=False)

Reproject a point from the bounding box to the global space

Parameters:

• xyz (np.ndarray) – point to reproject

• inplace (bool, optional) – Whether to modify the input array in place, by default False

Returns:

np.ndarray – reprojected point

to_dict() → dict

Export the defining characteristics of the bounding box to a dictionary for json serialisation

Returns:

dict – dictionary with origin, maximum and nsteps

property valid

Check if the bounding box has valid origin and maximum values.

Returns:

bool – True if both origin and maximum are set, False otherwise

property volume

Calculate the volume of the bounding box.

Returns:

float – Volume of the bounding box

vtk()

Export the model as a pyvista RectilinearGrid

Returns:

pv.RectilinearGrid – a pyvista grid object

Raises:

ImportError – If pyvista is not installed raise import error

with_buffer(buffer: float = 0.2) → BoundingBox

Create a new bounding box with a buffer around the existing bounding box

Parameters:

buffer (float, optional) – percentage to expand the dimensions by, by default 0.2

Returns:

BoundingBox – The new bounding box object.

Raises:

LoopValueError – if the current bounding box is invalid