Computing Exact Global Accessibility Cones for Polyhedral Objects
Savinder Dhaliwal, Satyandra K. Gupta, Jim Huang · 2000
Abstract This paper describes an algorithm for computing exact global accessibility cones for various faces (i.e., the set of directions from which various faces are accessible) of a polyhedral object. In contrast to previously published algorithms that compute approximate global accessibility cones for a face by sampling a set of discrete points from the face, the algorithm presented in this paper computes the exact global accessibility cones. In this paper, we describe exact mathematical conditions and the associated procedure for determining the set of directions from which a planar face with triangular boundary is inaccessible due to another face in the object. By utilizing the procedure to compute the exact inaccessibility region for a face, we present an algorithm for computing global accessibility cones for various faces in the object. These global accessibility cones are represented in a convenient matrix and can be used to support a wide variety of accessibility queries for the object.