Triangle: -q switch (original) (raw)

The -q switch

Quality mesh generation by my variant of a hybrid ofJim Ruppert's Delaunay refinement algorithm and Paul Chew's Delaunay refinement algorithm. (Ruppert's paper describing his algorithm, and my papers describing my variations, are available from the Research Credit page.)
Adds vertices to the mesh to ensure that no angle smaller than 20o occurs. Clearly, small angles between input segments cannot be eliminated; usually, all other small angles are.
An alternative minimum angle may be specified after the `q'. For instance, -q14.3 specifies a minimum angle of 14.3o.
If the minimum angle is 20.7o or smaller, the triangulation algorithm is theoretically guaranteed to terminate (assuming infinite precision arithmetic - Triangle may fail to terminate if you run out of precision).
In practice, the algorithm often succeeds for minimum angles up to 33o. It usually doesn't terminate for angles above 34o.
For some meshes, however, it may be necessary to reduce the minimum angle to well below 20o to avoid problems associated with insufficient floating-point precision. Detailed information on quality meshing.