T-junction Elimination

I encontered some artifacts when rendering stencil shadows from md2 meshes. As it turned out, even a low-poly models from Quake II are not without bugs (I was hoping that everything will be fine). Apparently this is due to the fact that initially they were not intended for casting the shadows, though one may notice, that they respected the rules of two-manifold geometry.

In general, the converter had to be refined so that it can determine non-adjacent clusters of triangles, eliminate T-junctions, do a search based on coincident vertices, etc. In the end I managed to get around of minor bugs and removed invalid triangles from mesh adjacency.

In general, a number of models does not contain any errors. But for example, the "bitch" lost en entire shoulder (as it turned out, there is some kind of porridge made of triangles).