Volumes

VDB-backed volume types, DICOM loading, and the vdb_loader helper submodule.

Volume types

class pyvcad.FloatVolume

A VDB volume storing scalar float values.

__init__(*args, **kwargs)

Overloaded function.

  1. __init__(self: pyvcad.pyvcad.FloatVolume) -> None

Constructor. Creates an empty FloatVDBVolume.

  1. __init__(self: pyvcad.pyvcad.FloatVolume, grid: openvdb::v13_0::Grid<openvdb::v13_0::tree::Tree<openvdb::v13_0::tree::RootNode<openvdb::v13_0::tree::InternalNode<openvdb::v13_0::tree::InternalNode<openvdb::v13_0::tree::LeafNode<float, 3u>, 4u>, 5u>>>>, center: bool = False) -> None

Constructor. Creates a FloatVDBVolume from an existing grid.

Parameters:

  • grid (FloatGrid) – The OpenVDB grid to use.

  • center (bool) – If True, centers the volume about the origin. Defaults to False.

bounding_box(self: pyvcad.pyvcad.FloatVolume) → tuple[pyvcad.pyvcad.Vec3, pyvcad.pyvcad.Vec3]

Get the world space bounding box of the volume.

Returns:

The minimum and maximum coordinates.

Return type:

tuple[Vec3, Vec3]

clone(self: pyvcad.pyvcad.FloatVolume) → pyvcad.pyvcad.FloatVolume

Create a thread-safe clone of this volume.

Returns:

A cloned volume instance.

Return type:

FloatVolume

grid_type(self: pyvcad.pyvcad.FloatVolume) → str

Get the grid type name.

Returns:

The grid type name.

Return type:

str

sample(self: pyvcad.pyvcad.FloatVolume, x: SupportsFloat, y: SupportsFloat, z: SupportsFloat) → float

Sample the volume at the given coordinates.

Parameters:

  • x (float) – X coordinate.

  • y (float) – Y coordinate.

  • z (float) – Z coordinate.

Returns:

The sampled value.

Return type:

float

class pyvcad.Vec2sVolume

A VDB volume storing 2D vector values with single precision.

__init__(self: pyvcad.pyvcad.Vec2sVolume) → None

Constructor. Creates an empty Vec2sVDBVolume.

bounding_box(self: pyvcad.pyvcad.Vec2sVolume) → tuple[pyvcad.pyvcad.Vec3, pyvcad.pyvcad.Vec3]

Get the world space bounding box of the volume.

Returns:

The minimum and maximum coordinates.

Return type:

tuple[Vec3, Vec3]

clone(self: pyvcad.pyvcad.Vec2sVolume) → pyvcad.pyvcad.Vec2sVolume

Create a thread-safe clone of this volume.

Returns:

A cloned volume instance.

Return type:

Vec2sVolume

grid_type(self: pyvcad.pyvcad.Vec2sVolume) → str

Get the grid type name.

Returns:

The grid type name.

Return type:

str

sample(self: pyvcad.pyvcad.Vec2sVolume, x: SupportsFloat, y: SupportsFloat, z: SupportsFloat) → pyvcad.pyvcad.Vec2

Sample the volume at the given coordinates.

Parameters:

  • x (float) – X coordinate.

  • y (float) – Y coordinate.

  • z (float) – Z coordinate.

Returns:

The sampled 2D vector value.

Return type:

Vec2

class pyvcad.Vec3sVolume

A VDB volume storing 3D vector values with single precision.

__init__(*args, **kwargs)

Overloaded function.

  1. __init__(self: pyvcad.pyvcad.Vec3sVolume) -> None

Constructor. Creates an empty Vec3sVDBVolume.

  1. __init__(self: pyvcad.pyvcad.Vec3sVolume, grid: openvdb::v13_0::Grid<openvdb::v13_0::tree::Tree<openvdb::v13_0::tree::RootNode<openvdb::v13_0::tree::InternalNode<openvdb::v13_0::tree::InternalNode<openvdb::v13_0::tree::LeafNode<openvdb::v13_0::math::Vec3<float>, 3u>, 4u>, 5u>>>>, center: bool = False) -> None

Constructor. Creates a Vec3sVDBVolume from an existing grid.

Parameters:

  • grid (Vec3SGrid) – The OpenVDB grid to use.

  • center (bool) – If True, centers the volume about the origin. Defaults to False.

bounding_box(self: pyvcad.pyvcad.Vec3sVolume) → tuple[pyvcad.pyvcad.Vec3, pyvcad.pyvcad.Vec3]

Get the world space bounding box of the volume.

Returns:

The minimum and maximum coordinates.

Return type:

tuple[Vec3, Vec3]

clone(self: pyvcad.pyvcad.Vec3sVolume) → pyvcad.pyvcad.Vec3sVolume

Create a thread-safe clone of this volume.

Returns:

A cloned volume instance.

Return type:

Vec3sVolume

grid_type(self: pyvcad.pyvcad.Vec3sVolume) → str

Get the grid type name.

Returns:

The grid type name.

Return type:

str

sample(self: pyvcad.pyvcad.Vec3sVolume, x: SupportsFloat, y: SupportsFloat, z: SupportsFloat) → pyvcad.pyvcad.Vec3

Sample the volume at the given coordinates.

Parameters:

  • x (float) – X coordinate.

  • y (float) – Y coordinate.

  • z (float) – Z coordinate.

Returns:

The sampled 3D vector value.

Return type:

Vec3

class pyvcad.Vec4sVolume

A VDB volume storing 4D vector values with single precision.

__init__(self: pyvcad.pyvcad.Vec4sVolume) → None

Constructor. Creates an empty Vec4sVDBVolume.

bounding_box(self: pyvcad.pyvcad.Vec4sVolume) → tuple[pyvcad.pyvcad.Vec3, pyvcad.pyvcad.Vec3]

Get the world space bounding box of the volume.

Returns:

The minimum and maximum coordinates.

Return type:

tuple[Vec3, Vec3]

clone(self: pyvcad.pyvcad.Vec4sVolume) → pyvcad.pyvcad.Vec4sVolume

Create a thread-safe clone of this volume.

Returns:

A cloned volume instance.

Return type:

Vec4sVolume

grid_type(self: pyvcad.pyvcad.Vec4sVolume) → str

Get the grid type name.

Returns:

The grid type name.

Return type:

str

sample(self: pyvcad.pyvcad.Vec4sVolume, x: SupportsFloat, y: SupportsFloat, z: SupportsFloat) → pyvcad.pyvcad.Vec4

Sample the volume at the given coordinates.

Parameters:

  • x (float) – X coordinate.

  • y (float) – Y coordinate.

  • z (float) – Z coordinate.

Returns:

The sampled 4D vector value.

Return type:

Vec4

Loaders

class pyvcad.DICOMLoader

A loader for DICOM image stacks that converts them to VDB volumes.

__init__(self: pyvcad.pyvcad.DICOMLoader, directory: str, center: bool = False, rescale_slope: SupportsFloat = -inf, rescale_intercept: SupportsFloat = -inf, slice_thickness: SupportsFloat = -inf, x_pixel_spacing: SupportsFloat = -inf, y_pixel_spacing: SupportsFloat = -inf) → None

Constructor. Creates a DICOMLoader for loading DICOM image stacks.

Parameters:

  • directory (str) – The directory containing the DICOM stack.

  • center (bool, optional) – Whether to center the volume at the origin. Default is false.

  • rescale_slope (double, optional) – The rescale slope to apply to pixel values.

  • rescale_intercept (double, optional) – The rescale intercept to apply to pixel values.

  • slice_thickness (double, optional) – The slice thickness in mm.

  • x_pixel_spacing (double, optional) – The pixel spacing in x direction in mm.

  • y_pixel_spacing (double, optional) – The pixel spacing in y direction in mm.

as_volume(self: pyvcad.pyvcad.DICOMLoader) → pyvcad.pyvcad.FloatVolume

Convert the loaded DICOM stack to a VDB volume.

Returns:

The resulting VDB volume.

Return type:

FloatVDBVolume

get_bounding_box(self: pyvcad.pyvcad.DICOMLoader) → tuple[pyvcad.pyvcad.Vec3, pyvcad.pyvcad.Vec3]

Get the axis-aligned bounding box of the loaded DICOM volume in mm.

Returns:

A tuple containing two glm.vec3 vectors representing the minimum and maximum corners of the bounding box ((min_x, min_y, min_z), (max_x, max_y, max_z)).

Return type:

tuple

get_dimensions(self: pyvcad.pyvcad.DICOMLoader) → pyvcad.pyvcad.Vec3

Get the physical dimensions of the loaded DICOM volume in mm.

Returns:

A vector containing the dimensions in x, y, and z directions (x_dim, y_dim, z_dim).

Return type:

glm.vec3

get_min_max_hu(self: pyvcad.pyvcad.DICOMLoader) → tuple[float, float]

Get the minimum and maximum Hounsfield Unit (HU) values in the loaded DICOM volume.

Returns:

A tuple containing the minimum and maximum HU values (min_hu, max_hu).

Return type:

tuple

get_rescale_intercept(self: pyvcad.pyvcad.DICOMLoader) → float

Get the rescale intercept used for converting pixel values to Hounsfield Units (HU).

Returns:

The rescale intercept.

Return type:

double

get_rescale_slope(self: pyvcad.pyvcad.DICOMLoader) → float

Get the rescale slope used for converting pixel values to Hounsfield Units (HU).

Returns:

The rescale slope.

Return type:

double

get_voxel_size(self: pyvcad.pyvcad.DICOMLoader) → pyvcad.pyvcad.Vec3

Get the voxel size of the loaded DICOM volume in mm.

Returns:

A vector containing the voxel size in x, y, and z directions (x_size, y_size, z_size).

Return type:

glm.vec3

pyvcad.vdb_loader

VDB file loading utilities