On the instability in the dimension of splines spaces over T-meshes

The present paper reveals the instability in the dimension of the spline space S(d"1,d"2,d"1-1,d"2-1,T) over certain types of T-meshes T, that is, the dimension is related to not only the topological information of T but also the geometry of T. This insight suggests us to pay much attention to the structure of the T-meshes in modeling with splines over T-meshes.