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Removed features which were deprecated in release 0.2.

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This commit is contained in:
David Williams
2012-12-03 21:22:57 +01:00
parent e7f4c69102
commit 7e38fc135e
13 changed files with 6 additions and 1618 deletions
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187
library/PolyVoxCore/include/PolyVoxCore/MeshDecimator.h
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/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
#ifndef __PolyVox_MeshDecimator_H__
#define __PolyVox_MeshDecimator_H__
#include "PolyVoxCore/SurfaceMesh.h"
#include "PolyVoxCore/Vector.h"
#include "PolyVoxCore/VertexTypes.h"
#include <bitset>
#include <vector>
namespace PolyVox
{
/// The MeshDecimator reduces the number of triangles in a mesh.
////////////////////////////////////////////////////////////////////////////////
/// Meshes generated by the PolyVox surface extractors typically have a very high
/// number of triangles in them. This can pose difficulties both for the rendering
/// storage of such meshes. The MeshDecimator provides a way of reducing the triangle
/// count with minimal visual effect.
///
/// The MeshDecimator is based on the principle of edge collapse, and currently works
/// with meshes generated by the MarchingCubesSurfaceExtractor or CubicSurfaceExtractor. It does
/// not work with meshes generated by the CubicSurfaceExtractorWithNormals, although
/// this may be addressed in the future. The algorithm iterates over each pair of
/// connected vertices in the mesh and attemps to determine if they can be collapsed
/// into a single vertex.
///
/// The main criteria used in deciding whether two vertices can collapse is whether
/// they have the same normal. In the case of the cubic surfaces the normals must be
/// exactly the same, whereas in the case of the Marching Cubes surfaces a threshold
/// is used to determine whether two normals are 'close enough'. Additional constraints
/// apply to vertices which lie on the edges of regions or on the boundary between two
/// regions - these vertices are much less likely to be collapsed.
///
/// Given a mesh called 'mesh', you can create a decimated version as follows:
/// \code
/// SurfaceMesh<PositionMaterial> decimatedMesh;
/// MeshDecimator<PositionMaterial> decimator(&mesh, &decimatedMesh);
/// decimator.execute();
/// \endcode
///
/// The above applies for a cubic mesh, for a Marching Cubes mesh you need to parametise
/// the MeshDecimator and resulting SurfaceMesh on the 'PositionMaterialNormal' type
/// instead of the 'PositionMaterial' type.
///
/// \deprecated
template <typename VertexType>
class MeshDecimator
{
//Used to keep track of when a vertex is
//on one or more faces of the region
enum RegionFaceFlags
{
RFF_ON_REGION_FACE_NEG_X,
RFF_ON_REGION_FACE_POS_X ,
RFF_ON_REGION_FACE_NEG_Y ,
RFF_ON_REGION_FACE_POS_Y ,
RFF_ON_REGION_FACE_NEG_Z ,
RFF_ON_REGION_FACE_POS_Z,
RFF_NO_OF_REGION_FACE_FLAGS
};
//Data about the initial mesh - this
//will be fill in once at the start
struct InitialVertexMetadata
{
Vector3DFloat normal;
bool isOnMaterialEdge;
std::bitset<RFF_NO_OF_REGION_FACE_FLAGS> isOnRegionFace;
};
//Representing a triangle for decimation purposes.
struct Triangle
{
uint32_t v0;
uint32_t v1;
uint32_t v2;
Vector3DFloat normal;
};
struct IntVertex
{
int32_t x;
int32_t y;
int32_t z;
uint32_t index;
IntVertex(int32_t xVal, int32_t yVal, int32_t zVal, uint32_t indexVal)
:x(xVal)
,y(yVal)
,z(zVal)
,index(indexVal)
{
}
bool operator==(const IntVertex& rhs) const
{
return (x == rhs.x) && (y == rhs.y) && (z == rhs.z);
}
bool operator<(const IntVertex& rhs) const
{
if (z < rhs.z)
return true;
if (rhs.z < z)
return false;
if (y < rhs.y)
return true;
if (rhs.y < y)
return false;
if (x < rhs.x)
return true;
if (rhs.x < x)
return false;
return false;
}
};
public:
///Constructor
POLYVOX_DEPRECATED MeshDecimator(const SurfaceMesh<VertexType>* pInputMesh, SurfaceMesh<VertexType>* pOutputMesh, float fEdgeCollapseThreshold = 0.95f);
///Performs the decimation.
POLYVOX_DEPRECATED void execute();
private:
void fillInitialVertexMetadata(std::vector<InitialVertexMetadata>& vecInitialVertexMetadata);
void buildConnectivityData(void);
bool attemptEdgeCollapse(uint32_t uSrc, uint32_t uDst);
const SurfaceMesh<VertexType>* m_pInputMesh;
SurfaceMesh<VertexType>* m_pOutputMesh;
uint32_t performDecimationPass(float m_fMinDotProductForCollapse);
bool isSubset(std::bitset<RFF_NO_OF_REGION_FACE_FLAGS> a, std::bitset<RFF_NO_OF_REGION_FACE_FLAGS> b);
bool canCollapseEdge(uint32_t uSrc, uint32_t uDst);
bool canCollapseNormalEdge(uint32_t uSrc, uint32_t uDst);
bool canCollapseRegionEdge(uint32_t uSrc, uint32_t uDst);
bool canCollapseMaterialEdge(uint32_t uSrc, uint32_t uDst);
bool collapseChangesFaceNormals(uint32_t uSrc, uint32_t uDst, float fThreshold);
//Data structures used during decimation
std::vector<bool> vertexLocked;
std::vector<uint32_t> vertexMapper;
std::vector<Triangle> m_vecTriangles;
std::vector< std::vector<uint32_t> > trianglesUsingVertex; //Should probably use vector of vectors, and resise in advance.
std::vector<InitialVertexMetadata> m_vecInitialVertexMetadata;
float m_fMinDotProductForCollapse;
};
}
#include "PolyVoxCore/MeshDecimator.inl"
#endif //__PolyVox_MeshDecimator_H__

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library/PolyVoxCore/include/PolyVoxCore/MeshDecimator.inl
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/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
namespace PolyVox
{
////////////////////////////////////////////////////////////////////////////////
/// Builds a MeshDecimator.
/// \param pInputMesh A pointer to the mesh to be decimated.
/// \param[out] pOutputMesh A pointer to where the result should be stored. Any existing
/// contents will be deleted.
/// \param fEdgeCollapseThreshold This is only use in the case of a Marching Cubes
/// surface and controls how close two normals must be to collapse. The dot product
/// between the normals is computed and compared to this threshold. A threshold of
/// 1.0 means nothing will collapse, a threshold of 0.0 means everything will collapse.
////////////////////////////////////////////////////////////////////////////////
template <typename VertexType>
MeshDecimator<VertexType>::MeshDecimator(const SurfaceMesh<VertexType>* pInputMesh, SurfaceMesh<VertexType>* pOutputMesh, float fEdgeCollapseThreshold)
:m_pInputMesh(pInputMesh)
,m_pOutputMesh(pOutputMesh)
,m_fMinDotProductForCollapse(fEdgeCollapseThreshold)
{
*m_pOutputMesh = *m_pInputMesh;
}
template <typename VertexType>
void MeshDecimator<VertexType>::execute()
{
//Sanity check.
if((m_pOutputMesh->m_vecVertices.empty()) || (m_pOutputMesh->m_vecTriangleIndices.empty()))
{
return;
}
buildConnectivityData();
fillInitialVertexMetadata(m_vecInitialVertexMetadata);
uint32_t noOfEdgesCollapsed;
do
{
noOfEdgesCollapsed = performDecimationPass(m_fMinDotProductForCollapse);
m_pOutputMesh->removeDegenerateTris();
if(noOfEdgesCollapsed > 0)
{
//Build the connectivity data for the next pass. If this is slow, then look
//at adjusting it (based on vertex mapper?) rather than bulding from scratch.
buildConnectivityData();
}
}while(noOfEdgesCollapsed > 0);
m_pOutputMesh->removeUnusedVertices();
//Decimation will have invalidated LOD levels.
m_pOutputMesh->m_vecLodRecords.clear();
LodRecord lodRecord;
lodRecord.beginIndex = 0;
lodRecord.endIndex = m_pOutputMesh->getNoOfIndices();
m_pOutputMesh->m_vecLodRecords.push_back(lodRecord);
}
template <typename VertexType>
void MeshDecimator<VertexType>::buildConnectivityData(void)
{
//Build a list of all the triangles, complete with face normals.
m_vecTriangles.clear();
m_vecTriangles.resize(m_pOutputMesh->m_vecTriangleIndices.size() / 3);
for(uint32_t triCt = 0; triCt < m_vecTriangles.size(); triCt++)
{
m_vecTriangles[triCt].v0 = m_pOutputMesh->m_vecTriangleIndices[triCt * 3 + 0];
m_vecTriangles[triCt].v1 = m_pOutputMesh->m_vecTriangleIndices[triCt * 3 + 1];
m_vecTriangles[triCt].v2 = m_pOutputMesh->m_vecTriangleIndices[triCt * 3 + 2];
Vector3DFloat v0Pos = m_pOutputMesh->m_vecVertices[m_vecTriangles[triCt].v0].position;
Vector3DFloat v1Pos = m_pOutputMesh->m_vecVertices[m_vecTriangles[triCt].v1].position;
Vector3DFloat v2Pos = m_pOutputMesh->m_vecVertices[m_vecTriangles[triCt].v2].position;
Vector3DFloat v0v1 = v1Pos - v0Pos;
Vector3DFloat v0v2 = v2Pos - v0Pos;
Vector3DFloat normal = v0v1.cross(v0v2);
normal.normalise();
m_vecTriangles[triCt].normal = normal;
}
//For each vertex, determine which triangles are using it.
trianglesUsingVertex.clear();
trianglesUsingVertex.resize(m_pOutputMesh->m_vecVertices.size());
for(uint32_t ct = 0; ct < trianglesUsingVertex.size(); ct++)
{
trianglesUsingVertex[ct].reserve(6);
}
for(uint32_t ct = 0; ct < m_vecTriangles.size(); ct++)
{
trianglesUsingVertex[m_vecTriangles[ct].v0].push_back(ct);
trianglesUsingVertex[m_vecTriangles[ct].v1].push_back(ct);
trianglesUsingVertex[m_vecTriangles[ct].v2].push_back(ct);
}
}
template <typename VertexType>
uint32_t MeshDecimator<VertexType>::performDecimationPass(float /*m_fMinDotProductForCollapse*/)
{
// Count how many edges we have collapsed
uint32_t noOfEdgesCollapsed = 0;
// The vertex mapper track whick vertices collapse onto which.
vertexMapper.clear();
vertexMapper.resize(m_pOutputMesh->m_vecVertices.size());
// Once a vertex is involved in a collapse (either because it
// moves onto a different vertex, or because a different vertex
// moves onto it) it is forbidden to take part in another collapse
// this pass. We enforce this by setting the vertex locked flag.
vertexLocked.clear();
vertexLocked.resize(m_pOutputMesh->m_vecVertices.size());
// Initialise the vectors
for(uint32_t ct = 0; ct < m_pOutputMesh->m_vecVertices.size(); ct++)
{
// Initiall all vertices points to themselves
vertexMapper[ct] = ct;
// All vertices are initially unlocked
vertexLocked[ct] = false;
}
//For each triangle...
for(uint32_t ctIter = 0; ctIter < m_vecTriangles.size(); ctIter++)
{
if(attemptEdgeCollapse(m_vecTriangles[ctIter].v0, m_vecTriangles[ctIter].v1))
{
++noOfEdgesCollapsed;
}
if(attemptEdgeCollapse(m_vecTriangles[ctIter].v1, m_vecTriangles[ctIter].v2))
{
++noOfEdgesCollapsed;
}
if(attemptEdgeCollapse(m_vecTriangles[ctIter].v2, m_vecTriangles[ctIter].v0))
{
++noOfEdgesCollapsed;
}
}
if(noOfEdgesCollapsed > 0)
{
//Fix up the indices
for(uint32_t triCt = 0; triCt < m_pOutputMesh->m_vecTriangleIndices.size(); triCt++)
{
uint32_t before = m_pOutputMesh->m_vecTriangleIndices[triCt];
uint32_t after = vertexMapper[m_pOutputMesh->m_vecTriangleIndices[triCt]];
if(before != after)
{
m_pOutputMesh->m_vecTriangleIndices[triCt] = vertexMapper[m_pOutputMesh->m_vecTriangleIndices[triCt]];
}
}
}
return noOfEdgesCollapsed;
}
template <typename VertexType>
bool MeshDecimator<VertexType>::attemptEdgeCollapse(uint32_t uSrc, uint32_t uDst)
{
//A vertex will be locked if it has already been involved in a collapse this pass.
if(vertexLocked[uSrc] || vertexLocked[uDst])
{
return false;
}
if(canCollapseEdge(uSrc, uDst))
{
//Move v0 onto v1
vertexMapper[uSrc] = uDst; //vertexMapper[v1];
vertexLocked[uSrc] = true;
vertexLocked[uDst] = true;
//Increment the counter
return true;
}
return false;
}
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseEdge(uint32_t uSrc, uint32_t uDst)
{
bool bCanCollapse = true;
if(m_vecInitialVertexMetadata[uSrc].isOnMaterialEdge)
{
bCanCollapse &= canCollapseMaterialEdge(uSrc, uDst);
}
if(m_vecInitialVertexMetadata[uSrc].isOnRegionFace.any())
{
bCanCollapse &= canCollapseRegionEdge(uSrc, uDst);
}
if(bCanCollapse) //Only bother with this if the earlier tests passed.
{
bCanCollapse &= canCollapseNormalEdge(uSrc, uDst);
}
return bCanCollapse;
}
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseRegionEdge(uint32_t uSrc, uint32_t uDst)
{
// We can collapse normal vertices onto edge vertices, and edge vertices
// onto corner vertices, but not vice-versa. Hence we check whether all
// the edge flags in the source vertex are also set in the destination vertex.
if(isSubset(m_vecInitialVertexMetadata[uSrc].isOnRegionFace, m_vecInitialVertexMetadata[uDst].isOnRegionFace) == false)
{
return false;
}
// In general adjacent regions surface meshes may collapse differently
// and this can cause cracks. We solve this by only allowing the collapse
// is the normals are exactly the same. We do not use the user provided
// tolerence here (but do allow for floating point error).
if(m_vecInitialVertexMetadata[uSrc].normal.dot(m_vecInitialVertexMetadata[uDst].normal) < 0.999f)
{
return false;
}
return true;
}
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseMaterialEdge(uint32_t /*uSrc*/, uint32_t /*uDst*/)
{
return false;
}
//This function should really use some work. For a start we already have the
//faces normals for the input mesh yet we are computing them on the fly here.
template <typename VertexType>
bool MeshDecimator<VertexType>::collapseChangesFaceNormals(uint32_t uSrc, uint32_t uDst, float fThreshold)
{
bool faceFlipped = false;
std::vector<uint32_t>& triangles = trianglesUsingVertex[uSrc];
for(std::vector<uint32_t>::iterator triIter = triangles.begin(); triIter != triangles.end(); triIter++)
{
uint32_t tri = *triIter;
const uint32_t& v0Old = m_pOutputMesh->m_vecTriangleIndices[tri * 3];
const uint32_t& v1Old = m_pOutputMesh->m_vecTriangleIndices[tri * 3 + 1];
const uint32_t& v2Old = m_pOutputMesh->m_vecTriangleIndices[tri * 3 + 2];
//Check if degenerate
if((v0Old == v1Old) || (v1Old == v2Old) || (v2Old == v0Old))
{
continue;
}
uint32_t v0New = v0Old;
uint32_t v1New = v1Old;
uint32_t v2New = v2Old;
if(v0New == uSrc)
v0New = uDst;
if(v1New == uSrc)
v1New = uDst;
if(v2New == uSrc)
v2New = uDst;
//Check if degenerate
if((v0New == v1New) || (v1New == v2New) || (v2New == v0New))
{
continue;
}
const Vector3DFloat& v0OldPos = m_pOutputMesh->m_vecVertices[vertexMapper[v0Old]].getPosition(); //Note: we need the vertex mapper here. These neighbouring vertices may have been moved.
const Vector3DFloat& v1OldPos = m_pOutputMesh->m_vecVertices[vertexMapper[v1Old]].getPosition();
const Vector3DFloat& v2OldPos = m_pOutputMesh->m_vecVertices[vertexMapper[v2Old]].getPosition();
const Vector3DFloat& v0NewPos = m_pOutputMesh->m_vecVertices[vertexMapper[v0New]].getPosition();
const Vector3DFloat& v1NewPos = m_pOutputMesh->m_vecVertices[vertexMapper[v1New]].getPosition();
const Vector3DFloat& v2NewPos = m_pOutputMesh->m_vecVertices[vertexMapper[v2New]].getPosition();
Vector3DFloat OldNormal = (v1OldPos - v0OldPos).cross(v2OldPos - v1OldPos);
Vector3DFloat NewNormal = (v1NewPos - v0NewPos).cross(v2NewPos - v1NewPos);
OldNormal.normalise();
NewNormal.normalise();
float dotProduct = OldNormal.dot(NewNormal);
//NOTE: I don't think we should be using the threshold here, we're just checking for a complete face flip
if(dotProduct < fThreshold)
{
//cout << " Face flipped!!" << endl;
faceFlipped = true;
/*vertexLocked[v0] = true;
vertexLocked[v1] = true;*/
break;
}
}
return faceFlipped;
}
// Returns true if every bit which is set in 'a' is also set in 'b'. The reverse does not need to be true.
template <typename VertexType>
bool MeshDecimator<VertexType>::isSubset(std::bitset<RFF_NO_OF_REGION_FACE_FLAGS> a, std::bitset<RFF_NO_OF_REGION_FACE_FLAGS> b)
{
bool result = true;
for(int ct = 0; ct < RFF_NO_OF_REGION_FACE_FLAGS; ct++)
{
if(a.test(ct))
{
if(b.test(ct) == false)
{
result = false;
break;
}
}
}
return result;
}
}

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library/PolyVoxCore/include/PolyVoxCore/SimpleInterface.h
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/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
#ifndef __PolyVox_SimpleInterface_H__
#define __PolyVox_SimpleInterface_H__
#include "PolyVoxCore/CubicSurfaceExtractorWithNormals.h"
#include "PolyVoxCore/MaterialDensityPair.h"
#include "PolyVoxCore/SimpleVolume.h"
#include "PolyVoxCore/MarchingCubesSurfaceExtractor.h"
namespace PolyVox
{
//The PolyVox simple interface only exposes one voxel type and one volume type. But if you like you can
//adjust these typedefs and rebuild the library in order to modify which one volume and voxel is exposed.
typedef SimpleVolume<MaterialDensityPair88> Volume;
typedef SurfaceMesh<PositionMaterialNormal> Mesh;
/// \deprecated
POLYVOX_DEPRECATED void extractCubicMesh(Volume& volume, const Region& region, Mesh& resultMesh);
/// \deprecated
POLYVOX_DEPRECATED void extractSmoothMesh(Volume& volume, const Region& region, Mesh& resultMesh);
}
#endif //__PolyVox_SimpleInterface_H__