GEOMETRIC AND COMPUTATIONAL ASPECTS OF GRAVITY CASTING

In the manufacturing industry, finding an orientation for a mould that eliminates surface defects and ensures a complete fill after the term ination of the gravity casting process is an important and difficult p roblem which has not previously been investigated formally. The paper initiates the study of the gravity casting process from a geometric pe rspective and presents an optimal theta(n log n) time algorithm that s olves this problem in 2D given an object of size n. The paper also cha racterizes the object shapes (modelled as simple polygons) that can be 1-filled and relate fillability to well known classes of polygons. Fo r certain classes of objects, an optimal direction of fillability can be determined in linear time.