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Degenerated triangles produced by triangulation - Printable Version

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Degenerated triangles produced by triangulation - alber - 01-31-2018

Greetings!

This is my first post and first of all, many thanks to programmers for such a great program!

I created a mesh in Wings3D and triangulated it. After exporting it to an .x file, I discovered that among the triangles there are several degenerated triangles, i.e. triangles whose three vertices are made up from two mesh vertices. In other words these triangles look like (and basically are) straight line segments. For example:

{{1, 1, 0}, {1, 1, 0}, {0, 1, 0}}

Are such cases allowed in the output of a triangulation algorithm? I don't see how such line segments can be used in the rendering (they don't add any mesh details not described by triangles: each such segment is included as a side in two adjacent "normal" triangles). Or is this a bug? Or just a known "legal" deficiency of the algorithm used, in which case such degenerated triangles are supposed simply to be ignored?

EDIT: the image with the mesh is attached. This is a tip of a table leg from a youtube tutorial. The degenerated triangle is residing between the two green dots (all four table legs have a degenerated triangle in this place).