The .ele format

SVR uses the .ele format devised by Shewchuk, generalized in the obvious way to higher dimension, to describe the simplices of the output. A .ele file is paired with a .node file: the .ele file contains only topological information, while the .node file contains only geometric information.

The format is a text file, consisting of a header describing the file, then a list of points. Empty lines are ignored, as is anything on the same line after a '#' comment character. The amount or type of whitespace is insignificant. Here is an example file, which is the Delaunay triangulation of the example given for the .node format:

6  3  0
1  1  5  2
2  5  1  3
3  2  5  6
4  6  3  4
5  3  6  5
6  6  4  2
The header: n d+1 nattr
Three numbers. First one is the number of elements that follow. The second is the number of points in a simplex, which is exactly one greater than the dimension (in two dimensions, this number should read '3'). The last field is currently ignored but is retained for compatibility with Triangle, Pyramid, and TetGen.

The nodes: id x y [z, ...]
The ID is an integer. IDs can start at any number, but must be consecutive from there. For compatibility with Triangle, Pyramid, and TetGen, use either 0 or 1 for the first ID, and make sure that you make the same choice for the corresponding .node file. The next d fields are integers, denoting vertices by the ID they have in the corresponding .node file. If nattr was set to a non-zero value, there must be the correct number of attributes following the list of vertices. They will be ignored.

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Last modified by Benoît Hudson
Tue Jan 15 17:06:31 CST 2008