Class ConvexHull3D

java.lang.Object
jaba.convexHull3d.ConvexHull3D
public class ConvexHull3D extends Object
This class constructs the convex hull for 3-classes model. We use the algorithm presented in Computational Geometry in C 2th edition by Joseph O'Rourke. The original algorithm is coded in C language and uses global variables. In order to make the concept of global variables available in Java, we adopt the Singleton pattern for the class ConvexHull3D. In order to make the code as much as possible similar to the original one we have implemented double linked lists in the C way (next and prev pointer inside the item). Exploiting the protected visibility for the pointer next and prev, we use this approach only inside this package. The result (a list of faces of the convex hull) is converted in a ArrayList before return. Unless for the aforementioned exceptions the code is as the original version, so for further information consult Computational Geometry in C 2th ed. by Joseph O'Rourke (Cambridge University Press).
Author:
Sebastiano Spicuglia 19:42 09/05/2011

  • Constructor Details

    • ConvexHull3D

      public ConvexHull3D()
      Creates a new ConvexHull3D object

  • Method Details

    • buildHull

      public ArrayList<HullFace> buildHull(HashSet<HullVertex> stations, boolean autoProject) throws AllPointsCoplanarExceptions, AllPointsCollinearException
      Builds the convex hull for the @stations set. It returns the faces (divided into triangles) of the convex hull.
      Parameters:
      stations - the set of vertices
      autoProject - if it is true the method explodes the @stations set, adding to it the projection on the planes xy, yz, zx of all points in the @stations set.
      Returns:
      It returns the faces (divided into triangles) of the convex hull.
      Throws:
      AllPointsCoplanarExceptions
      AllPointsCollinearException

    • addEdge

      protected void addEdge(HullEdge p)
      Adds the @p edge to the global list of edges
      Parameters:
      p - the edge you want to add

    • addFace

      protected void addFace(HullFace p)
      Adds the @p face to the global list of faces
      Parameters:
      p - the face you want to add

    • addVertex

      protected void addVertex(HullVertex p)
      Adds the @p vertex to the global list of vertices
      Parameters:
      p - the vertex you want to add