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Work on MeshDecimator.

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This commit is contained in:
David Williams
2011-01-02 15:28:02 +00:00
parent 6b78768ba0
commit fff36662a5
2 changed files with 94 additions and 248 deletions
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19
library/PolyVoxCore/include/MeshDecimator.h
View File

@ -39,13 +39,6 @@ namespace PolyVox
NF_NO_OF_FLAGS
};
enum Stages
{
STAGE_FACE,
STAGE_EDGE,
NO_OF_STAGES
};
struct VertexMetadata
{
bool hasDuplicate;
@ -54,6 +47,8 @@ namespace PolyVox
int noOfDifferentNormals;
Vector3DFloat normal;
std::bitset<NF_NO_OF_FLAGS> m_bNormalFlags;
bool isOnRegionEdge;
bool isOnMaterialEdge;
};
template <typename VertexType>
@ -68,8 +63,6 @@ namespace PolyVox
void fillVertexMetadata(std::vector<VertexMetadata>& vecVertexMetadata);
int countZeros(void);
SurfaceMesh<VertexType>* m_pInputMesh;
//SurfaceMesh<PositionMaterial>* pMeshOutput;
@ -79,6 +72,10 @@ namespace PolyVox
bool isSubsetCubic(std::bitset<NF_NO_OF_FLAGS> a, std::bitset<NF_NO_OF_FLAGS> b);
bool canCollapseEdge(uint32_t uSrc, uint32_t uDest);
bool canCollapseNormalEdge(uint32_t uSrc, uint32_t uDest);
bool canCollapseRegionEdge(uint32_t uSrc, uint32_t uDest);
bool canCollapseMaterialEdge(uint32_t uSrc, uint32_t uDest);
bool collapseCausesFaceFlip(uint32_t uSrc, uint32_t uDest);
//Data structures used during decimation
std::vector<uint8_t> m_vecNoOfNeighboursUsingMaterial;
@ -91,16 +88,12 @@ namespace PolyVox
vector<int> vecOfTriCts;
vector<Vector3DFloat> vecOfTriNormals;
int m_NoOfZeros;
//vector<int> noOfDifferentNormals;
vector<VertexMetadata> m_vecInitialVertexMetadata;
vector<VertexMetadata> m_vecCurrentVertexMetadata;
float fMinDotProductForCollapse;
uint8_t m_uStage;
};
}

303
library/PolyVoxCore/include/MeshDecimator.inl
View File

@ -40,7 +40,6 @@ namespace PolyVox
fillVertexMetadata(m_vecInitialVertexMetadata);
m_uStage = STAGE_FACE;
uint32_t noOfEdgesCollapsed;
do
{
@ -69,6 +68,10 @@ namespace PolyVox
vecVertexMetadata[ct].materialKey = 0;
vecVertexMetadata[ct].trianglesUsingVertex.clear();
vecVertexMetadata[ct].noOfDifferentNormals = 0;
vecVertexMetadata[ct].normal.setElements(0,0,0);
vecVertexMetadata[ct].m_bNormalFlags.reset();
vecVertexMetadata[ct].isOnRegionEdge = false;
vecVertexMetadata[ct].isOnMaterialEdge = false;
}
//Determine triangles using each vertex
@ -92,6 +95,9 @@ namespace PolyVox
{
vecVertexMetadata[innerCt].hasDuplicate = true;
vecVertexMetadata[outerCt].hasDuplicate = true;
vecVertexMetadata[innerCt].isOnMaterialEdge = true;
vecVertexMetadata[outerCt].isOnMaterialEdge = true;
}
}
}
@ -171,12 +177,13 @@ namespace PolyVox
vecVertexMetadata[ct].normal = sumOfNormals;
vecVertexMetadata[ct].normal.normalise();
}
/*if(vecVertexMetadata[ct].noOfDifferentNormals == 3)
std::cout << "CORNER at " << ct <<std::endl;*/
//assert(noOfDifferentNormals[ct] > 0);
Vector3DFloat offset = static_cast<Vector3DFloat>(m_pInputMesh->m_Region.getLowerCorner());
for(int ct = 0; ct < m_pInputMesh->m_vecVertices.size(); ct++)
{
bool bInside = m_pInputMesh->m_Region.containsPoint(m_pInputMesh->m_vecVertices[ct].getPosition() + offset);
vecVertexMetadata[ct].isOnRegionEdge = !bInside;
}
//std::cout << "----------" <<std::endl;
@ -250,8 +257,6 @@ namespace PolyVox
}
}
m_NoOfZeros = countZeros();
if(noOfEdgesCollapsed > 0)
{
//Fix up the indices
@ -266,8 +271,6 @@ namespace PolyVox
}
}
m_NoOfZeros = countZeros();
return noOfEdgesCollapsed;
}
@ -351,21 +354,21 @@ namespace PolyVox
}
//template <typename VertexType>
bool MeshDecimator<PositionMaterialNormal>::canCollapseEdge(uint32_t v0, uint32_t v1)
bool MeshDecimator<PositionMaterialNormal>::canCollapseEdge(uint32_t uSrc, uint32_t uDst)
{
//A vertex will be locked if it has already been involved in a collapse this pass.
if(vertexLocked[v0] || vertexLocked[v1])
if(vertexLocked[uSrc] || vertexLocked[uDst])
{
return false;
}
if(m_pInputMesh->m_vecVertices[v0].getMaterial() != m_pInputMesh->m_vecVertices[v1].getMaterial())
if(m_pInputMesh->m_vecVertices[uSrc].getMaterial() != m_pInputMesh->m_vecVertices[uDst].getMaterial())
{
return false;
}
//For now, don't collapse vertices on material edges...
if(m_pInputMesh->m_vecVertices[v0].isOnMaterialEdge() || m_pInputMesh->m_vecVertices[v1].isOnMaterialEdge())
if(m_pInputMesh->m_vecVertices[uSrc].isOnMaterialEdge() || m_pInputMesh->m_vecVertices[uDst].isOnMaterialEdge())
{
if(true)
{
@ -377,16 +380,16 @@ namespace PolyVox
// have four neighbours with the same material. If it's on a corner it will have a
// different number. We only collapse straight edges to avoid changingthe shape of the
// material boundary.
if(m_vecNoOfNeighboursUsingMaterial[v0] == m_vecNoOfNeighboursUsingMaterial[v1])
if(m_vecNoOfNeighboursUsingMaterial[uSrc] == m_vecNoOfNeighboursUsingMaterial[uDst])
{
if(m_vecNoOfNeighboursUsingMaterial[v0] == 4)
if(m_vecNoOfNeighboursUsingMaterial[uSrc] == 4)
{
allMatch = true;
}
}
bool movementValid = false;
Vector3DFloat movement = m_pInputMesh->m_vecVertices[v1].getPosition() - m_pInputMesh->m_vecVertices[v0].getPosition();
Vector3DFloat movement = m_pInputMesh->m_vecVertices[uDst].getPosition() - m_pInputMesh->m_vecVertices[uSrc].getPosition();
movement.normalise();
if(movement.dot(Vector3DFloat(0,0,1)) > 0.999)
{
@ -436,7 +439,7 @@ namespace PolyVox
// Vertices on the geometrical edge of surface meshes need special handling.
// We check for this by whether any of the edge flags are set.
if(m_pInputMesh->m_vecVertices[v0].m_bFlags.any() || m_pInputMesh->m_vecVertices[v1].m_bFlags.any())
if(m_pInputMesh->m_vecVertices[uSrc].m_bFlags.any() || m_pInputMesh->m_vecVertices[uDst].m_bFlags.any())
{
// Assume we can't collapse until we prove otherwise...
bool bCollapseGeometryEdgePair = false;
@ -444,13 +447,13 @@ namespace PolyVox
// 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_pInputMesh->m_vecVertices[v0].m_bFlags, m_pInputMesh->m_vecVertices[v1].m_bFlags))
if(isSubset(m_pInputMesh->m_vecVertices[uSrc].m_bFlags, m_pInputMesh->m_vecVertices[uDst].m_bFlags))
{
// 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_pInputMesh->m_vecVertices[v0].getNormal().dot(m_pInputMesh->m_vecVertices[v1].getNormal()) > 0.999)
if(m_pInputMesh->m_vecVertices[uSrc].getNormal().dot(m_pInputMesh->m_vecVertices[uDst].getNormal()) > 0.999)
{
// Ok, this pair can collapse.
bCollapseGeometryEdgePair = true;
@ -465,93 +468,14 @@ namespace PolyVox
}
//Check the normals are within the threashold.
if(m_pInputMesh->m_vecVertices[v0].getNormal().dot(m_pInputMesh->m_vecVertices[v1].getNormal()) < fMinDotProductForCollapse)
if(m_pInputMesh->m_vecVertices[uSrc].getNormal().dot(m_pInputMesh->m_vecVertices[uDst].getNormal()) < fMinDotProductForCollapse)
{
return false;
}
////////////////////////////////////////////////////////////////////////////////
//The last test is whether we will flip any of the faces
bool faceFlipped = false;
//list<uint32_t> triangles = trianglesUsingVertexCurrently[v0];
list<uint32_t> triangles = m_vecCurrentVertexMetadata[v0].trianglesUsingVertex;
/*set<uint32_t> triangles;
std::set_union(trianglesUsingVertex[v0].begin(), trianglesUsingVertex[v0].end(),
trianglesUsingVertex[v1].begin(), trianglesUsingVertex[v1].end(),
std::inserter(triangles, triangles.begin()));*/
for(list<uint32_t>::iterator triIter = triangles.begin(); triIter != triangles.end(); triIter++)
{
uint32_t tri = *triIter;
uint32_t v0Old = m_pInputMesh->m_vecTriangleIndices[tri * 3];
uint32_t v1Old = m_pInputMesh->m_vecTriangleIndices[tri * 3 + 1];
uint32_t v2Old = m_pInputMesh->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 == v0)
v0New = v1;
if(v1New == v0)
v1New = v1;
if(v2New == v0)
v2New = v1;
//Check if degenerate
if((v0New == v1New) || (v1New == v2New) || (v2New == v0New))
{
continue;
}
Vector3DFloat v0OldPos = m_pInputMesh->m_vecVertices[vertexMapper[v0Old]].getPosition();
Vector3DFloat v1OldPos = m_pInputMesh->m_vecVertices[vertexMapper[v1Old]].getPosition();
Vector3DFloat v2OldPos = m_pInputMesh->m_vecVertices[vertexMapper[v2Old]].getPosition();
Vector3DFloat v0NewPos = m_pInputMesh->m_vecVertices[vertexMapper[v0New]].getPosition();
Vector3DFloat v1NewPos = m_pInputMesh->m_vecVertices[vertexMapper[v1New]].getPosition();
Vector3DFloat v2NewPos = m_pInputMesh->m_vecVertices[vertexMapper[v2New]].getPosition();
/*Vector3DFloat v0OldPos = m_vecVertices[v0Old].getPosition();
Vector3DFloat v1OldPos = m_vecVertices[v1Old].getPosition();
Vector3DFloat v2OldPos = m_vecVertices[v2Old].getPosition();
Vector3DFloat v0NewPos = m_vecVertices[v0New].getPosition();
Vector3DFloat v1NewPos = m_vecVertices[v1New].getPosition();
Vector3DFloat v2NewPos = m_vecVertices[v2New].getPosition();*/
Vector3DFloat OldNormal = (v1OldPos - v0OldPos).cross(v2OldPos - v1OldPos);
Vector3DFloat NewNormal = (v1NewPos - v0NewPos).cross(v2NewPos - v1NewPos);
OldNormal.normalise();
NewNormal.normalise();
// Note for after holiday - We are still getting faces flipping despite the following test. I tried changing
// the 0.0 to 0.9 (which should still let coplanar faces merge) but oddly nothing then merged. Investigate this.
float dotProduct = OldNormal.dot(NewNormal);
//cout << dotProduct << endl;
if(dotProduct < 0.9f)
{
//cout << " Face flipped!!" << endl;
faceFlipped = true;
/*vertexLocked[v0] = true;
vertexLocked[v1] = true;*/
break;
}
}
if(faceFlipped == true)
if(collapseCausesFaceFlip(uSrc,uDst))
{
return false;
}
@ -559,75 +483,83 @@ namespace PolyVox
}
//template <typename VertexType>
bool MeshDecimator<PositionMaterial>::canCollapseEdge(uint32_t v0, uint32_t v1)
bool MeshDecimator<PositionMaterial>::canCollapseEdge(uint32_t uSrc, uint32_t uDst)
{
//A vertex will be locked if it has already been involved in a collapse this pass.
if(vertexLocked[v0] || vertexLocked[v1])
if(vertexLocked[uSrc] || vertexLocked[uDst])
{
return false;
}
if(m_pInputMesh->m_vecVertices[v0].getMaterial() != m_pInputMesh->m_vecVertices[v1].getMaterial())
if(m_vecInitialVertexMetadata[uSrc].isOnMaterialEdge)
{
if(m_vecInitialVertexMetadata[uSrc].isOnRegionEdge)
{
assert(false); //Shouldn't be on both edge types.
return false;
}
else
{
return canCollapseMaterialEdge(uSrc, uDst);
}
}
else
{
if(m_vecInitialVertexMetadata[uSrc].isOnRegionEdge)
{
return canCollapseRegionEdge(uSrc, uDst);
}
else
{
return canCollapseNormalEdge(uSrc, uDst);
}
}
}
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseNormalEdge(uint32_t uSrc, uint32_t uDst)
{
if(m_vecInitialVertexMetadata[uSrc].m_bNormalFlags.count() == 3) //Corner
{
return false;
}
if(m_vecInitialVertexMetadata[v0].m_bNormalFlags.count() == 3) //Corner
if(isSubsetCubic(m_vecInitialVertexMetadata[uSrc].m_bNormalFlags, m_vecInitialVertexMetadata[uDst].m_bNormalFlags) == false)
{
return false;
}
if(m_vecInitialVertexMetadata[v0].m_bNormalFlags.count() == 2) //Edge
{
if(isSubsetCubic(m_vecInitialVertexMetadata[v0].m_bNormalFlags, m_vecInitialVertexMetadata[v1].m_bNormalFlags) == false)
if(collapseCausesFaceFlip(uSrc, uDst))
{
return false;
}
}
if(m_vecInitialVertexMetadata[v0].m_bNormalFlags.count() == 1) //Face
{
if(isSubsetCubic(m_vecInitialVertexMetadata[v0].m_bNormalFlags, m_vecInitialVertexMetadata[v1].m_bNormalFlags) == false)
{
return false;
}
}
/*if(m_vecInitialVertexMetadata[v0].normal.dot(m_vecInitialVertexMetadata[v1].normal) < 0.999f)
/*if(m_vecInitialVertexMetadata[uSrc].normal.dot(m_vecInitialVertexMetadata[v1].normal) < 0.999f)
{
return false;
}*/
if(m_vecInitialVertexMetadata[v0].hasDuplicate)
{
bool canMerge = false;
/*if(m_vecInitialVertexMetadata[v1].hasDuplicate)
{
if(isSubsetCubic(m_vecInitialVertexMetadata[v0].m_bNormalFlags, m_vecInitialVertexMetadata[v1].m_bNormalFlags))
{
canMerge = true;
}
}*/
return canMerge;
return true;
}
Vector3DFloat offset = static_cast<Vector3DFloat>(m_pInputMesh->m_Region.getLowerCorner());
bool v0Inside = m_pInputMesh->m_Region.containsPoint(m_pInputMesh->m_vecVertices[v0].getPosition() + offset);
bool v1Inside = m_pInputMesh->m_Region.containsPoint(m_pInputMesh->m_vecVertices[v1].getPosition() + offset);
if(v0Inside == false)
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseRegionEdge(uint32_t uSrc, uint32_t uDst)
{
return false;
}
template <typename VertexType>
bool MeshDecimator<VertexType>::canCollapseMaterialEdge(uint32_t uSrc, uint32_t uDst)
{
return false;
}
////////////////////////////////////////////////////////////////////////////////
//The last test is whether we will flip any of the faces
template <typename VertexType>
bool MeshDecimator<VertexType>::collapseCausesFaceFlip(uint32_t uSrc, uint32_t uDst)
{
bool faceFlipped = false;
//list<uint32_t> triangles = trianglesUsingVertexCurrently[v0];
list<uint32_t> triangles = m_vecCurrentVertexMetadata[v0].trianglesUsingVertex;
list<uint32_t> triangles = m_vecCurrentVertexMetadata[uSrc].trianglesUsingVertex;
/*set<uint32_t> triangles;
std::set_union(trianglesUsingVertex[v0].begin(), trianglesUsingVertex[v0].end(),
trianglesUsingVertex[v1].begin(), trianglesUsingVertex[v1].end(),
@ -651,12 +583,12 @@ namespace PolyVox
uint32_t v1New = v1Old;
uint32_t v2New = v2Old;
if(v0New == v0)
v0New = v1;
if(v1New == v0)
v1New = v1;
if(v2New == v0)
v2New = v1;
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))
@ -703,85 +635,6 @@ namespace PolyVox
}
}
if(faceFlipped == true)
{
return false;
}
/*if(m_vecInitialVertexMetadata[v0].trianglesUsingVertex.size() != m_vecInitialVertexMetadata[v1].trianglesUsingVertex.size())
{
return false;
}*/
/*if(m_vecInitialVertexMetadata[v0].noOfDifferentNormals == 3)
{
return false;
}*/
/*if(m_vecInitialVertexMetadata[v1].noOfDifferentNormals == 3)
{
return false;
}*/
/*if(m_vecInitialVertexMetadata[v0].noOfDifferentNormals > m_vecInitialVertexMetadata[v1].noOfDifferentNormals)
{
return false;
}*/
/*if(m_vecInitialVertexMetadata[v0].materialKey != m_vecInitialVertexMetadata[v1].materialKey)
{
return false;
}*/
/*if((hasDuplicate[v0]) || (hasDuplicate[v1]))
{
return false;
}*/
/*if(m_vecInitialVertexMetadata[v0].hasDuplicate)
{
//if(!hasDuplicate[v1])
{
return false;
}
}*/
return true;
}
template <typename VertexType>
int MeshDecimator<VertexType>::countZeros(void)
{
int total = 0;
for(int ct = 0; ct < m_pInputMesh->m_vecTriangleIndices.size(); ct++)
{
if(m_pInputMesh->m_vecTriangleIndices[ct] == 0)
{
total++;
return faceFlipped;
}
}
return total;
}
}
#ifdef BLAH
Vector3DFloat offset = static_cast<Vector3DFloat>(m_pInputMesh->m_Region.getLowerCorner());
bool v0Inside = m_pInputMesh->m_Region.containsPoint(m_pInputMesh->m_vecVertices[v0].getPosition() + offset);
bool v1Inside = m_pInputMesh->m_Region.containsPoint(m_pInputMesh->m_vecVertices[v1].getPosition() + offset);
if(v0Inside == false)
{
/*if(v1Inside == false)
{
//if(noOfDifferentNormals[v0] > 1)
if(trianglesUsingVertex[v0].size() != trianglesUsingVertex[v1].size())
//if(materialKey[v0] != materialKey[v1])
{
return false;
}
}
else*/
{
return false;
}
}
#endif