Mesh coarsening (deleting mesh points) is now possible. Two ways are implemented for doing mesh coarsening: (1) The user can specify the points wanted to be removed by using the "pointmarker" list (i.e., the last column in .node file), a '0' means "remove this point", otherwise "keep it"; or (2) The user can supply a mesh sizing function, let TetGen choose the point to remove, i.e., TetGen will remove a point if the mesh size at the point is too dense.
The new command line option for mesh coarsening is '-R'. It can be used either with '-p' (to coarse a CDT) or '-r' (to coarse a previously generated mesh). You can also use '-R' and '-q' together. TetGen will first perform mesh coarsening then do mesh refinement, hence the process must terminate and the mesh quality is improved.