A mesh is a collection of points, with connectivity information. Usually the points are stored as a sequence of coordinates. The connectivity informations can correspond to edges or faces. They are described as sets of indices of the points which form the edge or the face. For triangular meshes, where all the faces are triangles, a triangle is stored as a triple of indices.

1.Example

Here is the file format used in axel to store surface meshes.

<surface type="mesh" name="polygirl"  color="255 0 0">
<off>
...
</off>
</surface>

(blue parts are optional).