Saitoh, TsuyoshiHosaka, Mamoru2015-10-052015-10-0519901017-4656https://doi.org/10.2312/egtp.19901011This paper describes methods of c o n s t r u c t i n g s u r f a c e patches which s a t i s f y independently given boundary conditions on a l l i t s four or t h r e e s i d e s . A patch c o n s i s t s of two p a r t s : one i s a patch s a t i s f y i n g a t l e a s t p o s i t i o n a l condition of the boundary curves, and the other gives n u l l position vectors and independent i t s f i r s t and second d e r i v a t i v e vectors on t h e i r boundaries. The l a t t e r i s used for compensating d e r i v a t i v e vectors t o s a t i s f y given boundary conditions. A network o f curves whose meshes are four or t h r e e s i d e s can be i n t e r p o l a t e d smoothly with patches of t h i s type.10.2312/egtp.19901011