Basic Examples (4)
Retrieve the ResourceFunction:
Get the boundary of a Simplex:
Get the boundary of a simplicial complex, represented as a list of simplices:
Get the boundary of a MeshRegion:
Scope (2)
By default, the boundary will be computed from simplices that match the dimension of the simplicial complex:
A different dimension k can be specified, which will find the boundary of the k-skeleton of the complex:
Generalizations and Extensions (1)
Some other primitives can represent a simplex as well:
Applications (2)
Find holes in a 3D model:
Highlight the boundary edges:
Properties and Relations (3)
Orientation is preserved:
The boundary of a boundary is always empty:
A graph can be considered a one-dimensional simplicial complex:
The boundary can give you information about degree of vertices:
Possible Issues (5)
Not all graphics primitives are valid simplices:
They can often be converted to simplicial complexes using DiscretizeGraphics that are reasonable approximations:
Valid n-dimensional simplices must have n+1 vertices:
Mesh regions are not necessarily composed of simplices:
TriangulateMesh can often be used to create a valid simplicial complex:
Vertices must be unique:
If orientations are not consistent within a simplicial complex, the boundary will not have consistent orientations, either:
Interactive Examples (1)
One can visualize 4D shapes by rotating and projecting the boundary into 3D. Here is an example using a hexadecachoron:
Neat Examples (2)
The boundary of an annulus is two circles, while the boundary of a Moebius strip is a single circle:
Get text outlines: