Package mgui.geometry.mesh

Class MeshDecimation

java.lang.Object
mgui.interfaces.Utility
mgui.geometry.mesh.MeshDecimation
public class MeshDecimation
extends Utility
Utility class for specialized functions dealing with mesh decimation.
Since:
1.0
Version:
1.0
Author:
Andrew Reid

  • Constructor Summary

    Constructors
    Constructor Description
    MeshDecimation()  

  • Method Summary

    Modifier and Type Method Description
    static void decimateNeighbours​(Mesh3D mesh)
    Decimates by removing nodes one-by-one, skipping boundary nodes: 1.
    static void decimateVTK​(Mesh3D mesh, double featureAngle, double errorThreshold, int targetSize, boolean ensureTarget)
    Decimates a mesh as decribed in:
    static void tagBoundaryNodes​(java.util.ArrayList<MguiBoolean> tagged, NeighbourhoodMesh n_mesh)
    Tag all boundary nodes.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • MeshDecimation

      public MeshDecimation()

  • Method Details

    • decimateVTK

      public static void decimateVTK​(Mesh3D mesh, double featureAngle, double errorThreshold, int targetSize, boolean ensureTarget)
      Decimates a mesh as decribed in:

      Knapp, Mesh decimation using VTK, and..

      Schroeder WJ, Zarge JA, Lorensen WE. (1992) Decimation of Triangle Meshes. Conference Proceedings of SIGGRAPH. pp. 65-70

      As follows:

      1. Represent mesh as an edge set

      2. Classify edges as feature edges if their opposing faces have an angle > threshold

      3. Classify vertices as:

      • Simple: surrounded by a complete cycle of triangles
      • Complex: like simple, but with one or more edges having multiple triangles
      • Boundary: surrounded by semi-cycle of triangles
      • Interior: Having exactly two feature edges
      • Corner: Having more than two feature edges

      4. Calculate and sort by error (mesh without this vertex compared to mesh with this vertex)

      5. Eliminate vertices starting with those having the lowest error, until either the specified target number (of remaining vertices) is met, or until no more vertices are below the error threshold (unless ensureTarget == true, in which case vertices will continue to be removed until the target size is met)

      Parameters:
      mesh - Mesh to decimate
      featureAngle - minimum angle above which edges are considered feature edges
      errorThreshold - maximum error beyond which vertices will not be removed (unless ensureTarget == true)
      targetSize - target number of vertices
      endureTarget - ensure that the the mesh is decimated to targetSize

    • decimateNeighbours

      public static void decimateNeighbours​(Mesh3D mesh)
      Decimates by removing nodes one-by-one, skipping boundary nodes: 1. random list of nodes & tags 2. get neighbourhood mesh 3. for each node 4. if not tagged and not boundary node 5. remove from mesh 6. tag 7. tag all neighbours
      Parameters:
      mesh - Mesh to decimate TODO: keep feature edges TODO: refine by comparing to original and iterating

    • tagBoundaryNodes

      public static void tagBoundaryNodes​(java.util.ArrayList<MguiBoolean> tagged, NeighbourhoodMesh n_mesh)
      Tag all boundary nodes.