Given a planar point set, we consider three classes of optimal triangulatio
ns: (1) the minimum weight triangulation with angular constraints (constrai
nts on the minimum angle and the maximum angle in a triangulation), (2) the
angular balanced triangulation which minimizes the sum of the ratios of th
e maximum angle to the minimum angle for each triangle, and (3) the area ba
lanced triangulation which minimizes the variance of the areas of triangles
in the triangulation. With appropriate definition of local optimality for
each class, a simple unified method is established for the computation of t
he subgraphs of optimal triangulations. Computational experiments demonstra
te that the method successfully identifies large portion of edges of the op
timal triangulations of each class for all problem instances tested, and he
nce optimal triangulations for each class can be obtained from them by appl
ying dynamic programming. (C) 2000 Elsevier Science B.V. All rights reserve
d.