NXcg_alpha_complex¶
Status:
base class, extends NXobject
Description:
Computational geometry description of alpha shapes or wrappings to primitives.
For details see:
https://dl.acm.org/doi/10.5555/871114 for weighted, and
https://doc.cgal.org/latest/Alpha_shapes_3 for 3D implementation
https://doc.cgal.org/latest/Manual/packages.html#PkgAlphaWrap3 for 3D wrap
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:
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. 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 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 shapes and alpha wrappings.
offset: (optional) NX_NUMBER {units=NX_LENGTH}
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.