Computing Covering Polyhedra of Non-Convex Objects
نویسندگان
چکیده
We present an algorithm to build covering polyhedra for digital 3D objects, by iteratively filling local concavities. The resulting covering polyhedron is convex and is a good approximation of the convex hull of the object. The algorithm uses 3 x 3 x 3 operators and requires a few minutes for a 128 x 128 x 128 image, when implemented on a sequential computer. Once the covering polyhedron has been obtained, the object concavities can be identified by subtracting the object from the polyhedron and suitably post-processing the set difference. Features characterising the concavities can then be extracted and used as a tool for quantitative shape analysis.
منابع مشابه
Approximating Smallest Containers for Packing Three-Dimensional Convex Objects
We investigate the problem of computing a minimum volume container for the non-overlapping packing of a given set of three-dimensional convex objects. Already the simplest versions of the problem are NPhard so that we cannot expect to find exact polynomial time algorithms. We give constant ratio approximation algorithms for packing axis-parallel (rectangular) cuboids under translation into an a...
متن کاملDetermining the minimum translational distance between two convex polyhedra
Convex Polyhedra S. A. Cameron R. K. Culley McDonnell Douglas Research Laboratories Arti cial Intelligence Technology Group St. Louis, MO, USA 63166 Abstract Given two objects we de ne the minimal translational distance (MTD) between them to be the length of the shortest relative translation that results in the objects being in contact. MTD is equivalent to the distance between two objects if t...
متن کاملSIZE AND GEOMETRY OPTIMIZATION OF TRUSS STRUCTURES USING THE COMBINATION OF DNA COMPUTING ALGORITHM AND GENERALIZED CONVEX APPROXIMATION METHOD
In recent years, the optimization of truss structures has been considered due to their several applications and their simple structure and rapid analysis. DNA computing algorithm is a non-gradient-based method derived from numerical modeling of DNA-based computing performance by new computers with DNA memory known as molecular computers. DNA computing algorithm works based on collective intelli...
متن کاملQuick Elimination of Non Interference Polytopes in Virtual Environments
The problem of collision detection is fundamental to interactive appli cations such as computer animation and virtual environments In these elds prompt recognition of possible impacts is important for computing real time response However existing algorithms do not eliminate non interfence objects e ciently This paper presents a practical algorithm to quickly eliminate most non interference conv...
متن کاملA Local Collision Avoidance Method for Non-strictly Convex Polyhedra
This paper proposes a local collision avoidance method for non-strictly convex polyhedra with continuous velocities. The main contribution of the method is that non-strictly convex polyhedra can be used as geometric models of the robot and the environment without any approximation. The problem of the continuous interaction generation between polyhedra is reduced to the continuous constraints ge...
متن کامل