3.3.3.40. NXcg_alpha_complex

Status:

base class, extends NXobject

Description:

Computational geometry description of alpha shapes or wrappings to primitives. ...

Computational geometry description of alpha shapes or wrappings to primitives.

For details see:

in CGAL, the Computational Geometry Algorithms Library. As a starting point, we follow the conventions of the CGAL library.

Symbols:

The symbols used in the schema to specify e.g. dimensions of arrays.

d: The dimensionality of the alpha shape, for now 2 or 3.

n_e: The number of edges.

n_f: The number of faces.

n_c: The number of cells.

Groups cited:

NXcg_point_set, NXcg_tetrahedron_set, NXcg_triangle_set

Structure:

dimensionality: (optional) NX_UINT {units=NX_UNITLESS}

Any of these values: 2 | 3

type: (optional) NX_CHAR

Specify which general type of alpha shape is computed. ...

Specify which general type of alpha shape is computed. Using for now the CGAL terminology. Basic means (unweighted) alpha shapes. Alpha_wrapping means meshes created using alpha wrapping procedures.

Any of these values: convex_hull | alpha_shape | alpha_wrapping

mode: (optional) NX_CHAR

Specifically when computed with the CGAL, the mode specifies if singular ...

Specifically when computed with the CGAL, the mode specifies if singular faces are removed (regularized) of the alpha complex.

Any of these values: general | regularized

alpha: (optional) NX_NUMBER {units=NX_LENGTH}

The alpha, (radius of the alpha-sphere) parameter to be used for alpha ...

The alpha, (radius of the alpha-sphere) parameter to be used for alpha shapes and alpha wrappings.

offset: (optional) NX_NUMBER {units=NX_LENGTH}

The offset distance parameter to be used in addition to alpha ...

The offset distance parameter to be used in addition to alpha in the case of alpha_wrapping.

point_set: (optional) NXcg_point_set

Point cloud for which the alpha shape or wrapping should be computed.

triangle_set: (optional) NXcg_triangle_set

Triangle soup for which the alpha wrapping should be computed.

triangulation: (optional) NXcg_triangle_set

A meshed representation of the resulting shape.

interior_cells: (optional) NXcg_tetrahedron_set

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/contributed_definitions/NXcg_alpha_complex.nxdl.xml