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HdMeshEdgeIndexTable Class Reference

#include <meshUtil.h>

Public Member Functions

 HdMeshEdgeIndexTable (HdMeshTopology const *topology)
 
 ~HdMeshEdgeIndexTable ()
 
bool GetVerticesForEdgeIndex (int edgeId, GfVec2i *edgeVerticesOut) const
 
bool GetVerticesForEdgeIndices (std::vector< int > const &edgeIndices, std::vector< GfVec2i > *edgeVerticesOut) const
 
bool GetEdgeIndices (GfVec2i const &edgeVertices, std::vector< int > *edgeIndicesOut) const
 

Detailed Description

Mesh edges are described as a pair of adjacent vertices encoded as GfVec2i.

The encoding of mesh edge indices is derived from the enumeration of face vertex index pairs provided by HdMeshUtil::EnumerateEdges().

This encoding is consistent across triangulation or quadrangulation of the base mesh faces as well as for non-manifold faces on refined subdivision surface meshes.

There can be multiple edge indices associated with each pair of topological vertices in the mesh, e.g. one for each face incident on the edge.

For example, here is a typical edge index assignment for a mesh with 2 quad faces and 6 vertices:

faceVertexCounts: [4, 4] faceVertexIndices: [0, 1, 4, 3, 1, 2, 5, 4]

edgeId:(edgeVertex[0], edgeVertex[1]) 

  2:(3,4)          6:(4,5)

3-------------—4-------------—5 | | |

Face 0 Face 1
3:(0,3) 1:(1,4)7:(1,4) 5:(2,5)

0-------------—1-------------—2 0:(0,1) 4:(1,2)

Notice that with this assignment, there are eight edge indices even though the mesh has seven topological edges. The mesh edge between vertex 1 and vertex 4 is associated with two edgeIds (1 and 7), one for each incident face.

This kind of edge index assignment can be implemented efficiently on the GPU since it falls out automatically from the primitive drawing order and requires minimal additional GPU data.

Definition at line 312 of file meshUtil.h.

Constructor & Destructor Documentation

HdMeshEdgeIndexTable::HdMeshEdgeIndexTable ( HdMeshTopology const *  topology)
explicit
HdMeshEdgeIndexTable::~HdMeshEdgeIndexTable ( )

Member Function Documentation

bool HdMeshEdgeIndexTable::GetEdgeIndices ( GfVec2i const &  edgeVertices,
std::vector< int > *  edgeIndicesOut 
) const
bool HdMeshEdgeIndexTable::GetVerticesForEdgeIndex ( int  edgeId,
GfVec2i *  edgeVerticesOut 
) const
bool HdMeshEdgeIndexTable::GetVerticesForEdgeIndices ( std::vector< int > const &  edgeIndices,
std::vector< GfVec2i > *  edgeVerticesOut 
) const
The documentation for this class was generated from the following file: