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polyvox/PolyVoxCore/source/SurfaceExtractorsDecimated.cpp

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#include "SurfaceExtractorsDecimated.h"
#include "BlockVolume.h"
#include "GradientEstimators.h"
#include "IndexedSurfacePatch.h"
#include "MarchingCubesTables.h"
#include "Region.h"
#include "RegionGeometry.h"
#include "VolumeChangeTracker.h"
#include "BlockVolumeIterator.h"
#include <algorithm>
using namespace std;
namespace PolyVox
{
uint32 getDecimatedIndex(uint32 x, uint32 y)
{
return x + (y * (POLYVOX_REGION_SIDE_LENGTH+1));
}
void generateDecimatedMeshDataForRegion(BlockVolume<uint8>* volumeData, uint8 uLevel, Region region, IndexedSurfacePatch* singleMaterialPatch)
{
singleMaterialPatch->m_vecVertices.clear();
singleMaterialPatch->m_vecTriangleIndices.clear();
//For edge indices
int32* vertexIndicesX0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
int32* vertexIndicesY0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
int32* vertexIndicesZ0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
int32* vertexIndicesX1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
int32* vertexIndicesY1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
int32* vertexIndicesZ1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
//Cell bitmasks
uint8* bitmask0 = new uint8[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
uint8* bitmask1 = new uint8[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
const uint8 uStepSize = uLevel == 0 ? 1 : 1 << uLevel;
//When generating the mesh for a region we actually look outside it in the
// back, bottom, right direction. Protect against access violations by cropping region here
Region regVolume = volumeData->getEnclosingRegion();
regVolume.setUpperCorner(regVolume.getUpperCorner() - Vector3DInt32(2*uStepSize-1,2*uStepSize-1,2*uStepSize-1));
region.cropTo(regVolume);
//Offset from volume corner
const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
//Create a region corresponding to the first slice
Region regSlice0(region);
Vector3DInt32 v3dUpperCorner = regSlice0.getUpperCorner();
v3dUpperCorner.setZ(regSlice0.getLowerCorner().getZ()); //Set the upper z to the lower z to make it one slice thick.
regSlice0.setUpperCorner(v3dUpperCorner);
//Iterator to access the volume data
BlockVolumeIterator<uint8> volIter(*volumeData);
//Compute bitmask for initial slice
uint32 uNoOfNonEmptyCellsForSlice0 = computeInitialDecimatedBitmaskForSlice(volIter, uLevel, regSlice0, offset, bitmask0);
if(uNoOfNonEmptyCellsForSlice0 != 0)
{
//If there were some non-empty cells then generate initial slice vertices for them
generateDecimatedVerticesForSlice(volIter, uLevel, regSlice0, offset, bitmask0, singleMaterialPatch, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0);
}
for(uint32 uSlice = 1; ((uSlice <= POLYVOX_REGION_SIDE_LENGTH) && (uSlice + offset.getZ() <= regVolume.getUpperCorner().getZ())); uSlice += uStepSize)
{
Region regSlice1(regSlice0);
regSlice1.shift(Vector3DInt32(0,0,uStepSize));
uint32 uNoOfNonEmptyCellsForSlice1 = computeDecimatedBitmaskForSliceFromPrevious(volIter, uLevel, regSlice1, offset, bitmask1, bitmask0);
if(uNoOfNonEmptyCellsForSlice1 != 0)
{
generateDecimatedVerticesForSlice(volIter, uLevel, regSlice1, offset, bitmask1, singleMaterialPatch, vertexIndicesX1, vertexIndicesY1, vertexIndicesZ1);
}
if((uNoOfNonEmptyCellsForSlice0 != 0) || (uNoOfNonEmptyCellsForSlice1 != 0))
{
generateDecimatedIndicesForSlice(volIter, uLevel, regSlice0, singleMaterialPatch, offset, bitmask0, bitmask1, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0, vertexIndicesX1, vertexIndicesY1, vertexIndicesZ1);
}
std::swap(uNoOfNonEmptyCellsForSlice0, uNoOfNonEmptyCellsForSlice1);
std::swap(bitmask0, bitmask1);
std::swap(vertexIndicesX0, vertexIndicesX1);
std::swap(vertexIndicesY0, vertexIndicesY1);
std::swap(vertexIndicesZ0, vertexIndicesZ1);
regSlice0 = regSlice1;
}
delete[] bitmask0;
delete[] bitmask1;
delete[] vertexIndicesX0;
delete[] vertexIndicesX1;
delete[] vertexIndicesY0;
delete[] vertexIndicesY1;
delete[] vertexIndicesZ0;
delete[] vertexIndicesZ1;
/*std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin();
while(iterSurfaceVertex != singleMaterialPatch->getVertices().end())
{
Vector3DFloat tempNormal = computeDecimatedNormal(volumeData, static_cast<Vector3DFloat>(iterSurfaceVertex->getPosition() + offset), CENTRAL_DIFFERENCE);
const_cast<SurfaceVertex&>(*iterSurfaceVertex).setNormal(tempNormal);
++iterSurfaceVertex;
}*/
}
uint32 computeInitialDecimatedBitmaskForSlice(BlockVolumeIterator<uint8>& volIter, uint8 uLevel, const Region& regSlice, const Vector3DFloat& offset, uint8* bitmask)
{
const uint8 uStepSize = uLevel == 0 ? 1 : 1 << uLevel;
uint32 uNoOfNonEmptyCells = 0;
//Iterate over each cell in the region
for(uint16 y = regSlice.getLowerCorner().getY(); y <= regSlice.getUpperCorner().getY(); y += uStepSize)
{
for(uint16 x = regSlice.getLowerCorner().getX(); x <= regSlice.getUpperCorner().getX(); x += uStepSize)
{
//Current position
volIter.setPosition(x,y,regSlice.getLowerCorner().getZ());
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8 iCubeIndex = 0;
if((x==regSlice.getLowerCorner().getX()) && (y==regSlice.getLowerCorner().getY()))
{
volIter.setPosition(x,y,regSlice.getLowerCorner().getZ());
const uint8 v000 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ());
const uint8 v100 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v010 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v110 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v001 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v101 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v011 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
if (v000 == 0) iCubeIndex |= 1;
if (v100 == 0) iCubeIndex |= 2;
if (v110 == 0) iCubeIndex |= 4;
if (v010 == 0) iCubeIndex |= 8;
if (v001 == 0) iCubeIndex |= 16;
if (v101 == 0) iCubeIndex |= 32;
if (v111 == 0) iCubeIndex |= 64;
if (v011 == 0) iCubeIndex |= 128;
}
else if((x>regSlice.getLowerCorner().getX()) && y==regSlice.getLowerCorner().getY())
{
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ());
const uint8 v100 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v110 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v101 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//x
uint8 iPreviousCubeIndexX = bitmask[getDecimatedIndex(x- offset.getX()-uStepSize,y- offset.getY())];
uint8 srcBit6 = iPreviousCubeIndexX & 64;
uint8 destBit7 = srcBit6 << 1;
uint8 srcBit5 = iPreviousCubeIndexX & 32;
uint8 destBit4 = srcBit5 >> 1;
uint8 srcBit2 = iPreviousCubeIndexX & 4;
uint8 destBit3 = srcBit2 << 1;
uint8 srcBit1 = iPreviousCubeIndexX & 2;
uint8 destBit0 = srcBit1 >> 1;
iCubeIndex |= destBit0;
if (v100 == 0) iCubeIndex |= 2;
if (v110 == 0) iCubeIndex |= 4;
iCubeIndex |= destBit3;
iCubeIndex |= destBit4;
if (v101 == 0) iCubeIndex |= 32;
if (v111 == 0) iCubeIndex |= 64;
iCubeIndex |= destBit7;
}
else if((x==regSlice.getLowerCorner().getX()) && (y>regSlice.getLowerCorner().getY()))
{
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v010 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v110 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v011 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//y
uint8 iPreviousCubeIndexY = bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY()-uStepSize)];
uint8 srcBit7 = iPreviousCubeIndexY & 128;
uint8 destBit4 = srcBit7 >> 3;
uint8 srcBit6 = iPreviousCubeIndexY & 64;
uint8 destBit5 = srcBit6 >> 1;
uint8 srcBit3 = iPreviousCubeIndexY & 8;
uint8 destBit0 = srcBit3 >> 3;
uint8 srcBit2 = iPreviousCubeIndexY & 4;
uint8 destBit1 = srcBit2 >> 1;
iCubeIndex |= destBit0;
iCubeIndex |= destBit1;
if (v110 == 0) iCubeIndex |= 4;
if (v010 == 0) iCubeIndex |= 8;
iCubeIndex |= destBit4;
iCubeIndex |= destBit5;
if (v111 == 0) iCubeIndex |= 64;
if (v011 == 0) iCubeIndex |= 128;
}
else
{
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ());
const uint8 v110 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//y
uint8 iPreviousCubeIndexY = bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY()-uStepSize)];
uint8 srcBit7 = iPreviousCubeIndexY & 128;
uint8 destBit4 = srcBit7 >> 3;
uint8 srcBit6 = iPreviousCubeIndexY & 64;
uint8 destBit5 = srcBit6 >> 1;
uint8 srcBit3 = iPreviousCubeIndexY & 8;
uint8 destBit0 = srcBit3 >> 3;
uint8 srcBit2 = iPreviousCubeIndexY & 4;
uint8 destBit1 = srcBit2 >> 1;
//x
uint8 iPreviousCubeIndexX = bitmask[getDecimatedIndex(x- offset.getX()-uStepSize,y- offset.getY())];
srcBit6 = iPreviousCubeIndexX & 64;
uint8 destBit7 = srcBit6 << 1;
srcBit2 = iPreviousCubeIndexX & 4;
uint8 destBit3 = srcBit2 << 1;
iCubeIndex |= destBit0;
iCubeIndex |= destBit1;
if (v110 == 0) iCubeIndex |= 4;
iCubeIndex |= destBit3;
iCubeIndex |= destBit4;
iCubeIndex |= destBit5;
if (v111 == 0) iCubeIndex |= 64;
iCubeIndex |= destBit7;
}
//Save the bitmask
bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())] = iCubeIndex;
if(edgeTable[iCubeIndex] != 0)
{
++uNoOfNonEmptyCells;
}
}
}
return uNoOfNonEmptyCells;
}
uint32 computeDecimatedBitmaskForSliceFromPrevious(BlockVolumeIterator<uint8>& volIter, uint8 uLevel, const Region& regSlice, const Vector3DFloat& offset, uint8* bitmask, uint8* previousBitmask)
{
const uint8 uStepSize = uLevel == 0 ? 1 : 1 << uLevel;
uint32 uNoOfNonEmptyCells = 0;
//Iterate over each cell in the region
for(uint16 y = regSlice.getLowerCorner().getY(); y <= regSlice.getUpperCorner().getY(); y += uStepSize)
{
for(uint16 x = regSlice.getLowerCorner().getX(); x <= regSlice.getUpperCorner().getX(); x += uStepSize)
{
//Current position
volIter.setPosition(x,y,regSlice.getLowerCorner().getZ());
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8 iCubeIndex = 0;
if((x==regSlice.getLowerCorner().getX()) && (y==regSlice.getLowerCorner().getY()))
{
volIter.setPosition(x,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v001 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v101 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v011 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//z
uint8 iPreviousCubeIndexZ = previousBitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())];
iCubeIndex = iPreviousCubeIndexZ >> 4;
if (v001 == 0) iCubeIndex |= 16;
if (v101 == 0) iCubeIndex |= 32;
if (v111 == 0) iCubeIndex |= 64;
if (v011 == 0) iCubeIndex |= 128;
}
else if((x>regSlice.getLowerCorner().getX()) && y==regSlice.getLowerCorner().getY())
{
volIter.setPosition(x+uStepSize,y,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v101 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//z
uint8 iPreviousCubeIndexZ = previousBitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())];
iCubeIndex = iPreviousCubeIndexZ >> 4;
//x
uint8 iPreviousCubeIndexX = bitmask[getDecimatedIndex(x- offset.getX()-uStepSize,y- offset.getY())];
uint8 srcBit6 = iPreviousCubeIndexX & 64;
uint8 destBit7 = srcBit6 << 1;
uint8 srcBit5 = iPreviousCubeIndexX & 32;
uint8 destBit4 = srcBit5 >> 1;
iCubeIndex |= destBit4;
if (v101 == 0) iCubeIndex |= 32;
if (v111 == 0) iCubeIndex |= 64;
iCubeIndex |= destBit7;
}
else if((x==regSlice.getLowerCorner().getX()) && (y>regSlice.getLowerCorner().getY()))
{
volIter.setPosition(x,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v011 = volIter.getSubSampledVoxel(uLevel);
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//z
uint8 iPreviousCubeIndexZ = previousBitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())];
iCubeIndex = iPreviousCubeIndexZ >> 4;
//y
uint8 iPreviousCubeIndexY = bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY()-uStepSize)];
uint8 srcBit7 = iPreviousCubeIndexY & 128;
uint8 destBit4 = srcBit7 >> 3;
uint8 srcBit6 = iPreviousCubeIndexY & 64;
uint8 destBit5 = srcBit6 >> 1;
iCubeIndex |= destBit4;
iCubeIndex |= destBit5;
if (v111 == 0) iCubeIndex |= 64;
if (v011 == 0) iCubeIndex |= 128;
}
else
{
volIter.setPosition(x+uStepSize,y+uStepSize,regSlice.getLowerCorner().getZ()+uStepSize);
const uint8 v111 = volIter.getSubSampledVoxel(uLevel);
//z
uint8 iPreviousCubeIndexZ = previousBitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())];
iCubeIndex = iPreviousCubeIndexZ >> 4;
//y
uint8 iPreviousCubeIndexY = bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY()-uStepSize)];
uint8 srcBit7 = iPreviousCubeIndexY & 128;
uint8 destBit4 = srcBit7 >> 3;
uint8 srcBit6 = iPreviousCubeIndexY & 64;
uint8 destBit5 = srcBit6 >> 1;
//x
uint8 iPreviousCubeIndexX = bitmask[getDecimatedIndex(x- offset.getX()-uStepSize,y- offset.getY())];
srcBit6 = iPreviousCubeIndexX & 64;
uint8 destBit7 = srcBit6 << 1;
iCubeIndex |= destBit4;
iCubeIndex |= destBit5;
if (v111 == 0) iCubeIndex |= 64;
iCubeIndex |= destBit7;
}
//Save the bitmask
bitmask[getDecimatedIndex(x- offset.getX(),y- offset.getY())] = iCubeIndex;
if(edgeTable[iCubeIndex] != 0)
{
++uNoOfNonEmptyCells;
}
}//For each cell
}
return uNoOfNonEmptyCells;
}
void generateDecimatedVerticesForSlice(BlockVolumeIterator<uint8>& volIter, uint8 uLevel, Region& regSlice, const Vector3DFloat& offset, uint8* bitmask, IndexedSurfacePatch* singleMaterialPatch,int32 vertexIndicesX[],int32 vertexIndicesY[],int32 vertexIndicesZ[])
{
const uint8 uStepSize = uLevel == 0 ? 1 : 1 << uLevel;
//Iterate over each cell in the region
for(uint16 y = regSlice.getLowerCorner().getY(); y <= regSlice.getUpperCorner().getY(); y += uStepSize)
{
for(uint16 x = regSlice.getLowerCorner().getX(); x <= regSlice.getUpperCorner().getX(); x += uStepSize)
{
//Current position
const uint16 z = regSlice.getLowerCorner().getZ();
volIter.setPosition(x,y,z);
const uint8 v000 = volIter.getSubSampledVoxel(uLevel);
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8 iCubeIndex = bitmask[getDecimatedIndex(x - offset.getX(),y - offset.getY())];
/* Cube is entirely in/out of the surface */
if (edgeTable[iCubeIndex] == 0)
{
continue;
}
/* Find the vertices where the surface intersects the cube */
if (edgeTable[iCubeIndex] & 1)
{
if(x != regSlice.getUpperCorner().getX())
{
volIter.setPosition(x + uStepSize,y,z);
const uint8 v100 = volIter.getSubSampledVoxel(uLevel);
const Vector3DFloat v3dPosition(x - offset.getX() + 0.5f * uStepSize, y - offset.getY(), z - offset.getZ());
const Vector3DFloat v3dNormal(v000 > v100 ? 1.0f : -1.0f,0.0,0.0);
const uint8 uMaterial = v000 | v100; //Because one of these is 0, the or operation takes the max.
SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesX[getDecimatedIndex(x - offset.getX(),y - offset.getY())] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 8)
{
if(y != regSlice.getUpperCorner().getY())
{
volIter.setPosition(x,y + uStepSize,z);
const uint8 v010 = volIter.getSubSampledVoxel(uLevel);
const Vector3DFloat v3dPosition(x - offset.getX(), y - offset.getY() + 0.5f * uStepSize, z - offset.getZ());
const Vector3DFloat v3dNormal(0.0,v000 > v010 ? 1.0f : -1.0f,0.0);
const uint8 uMaterial = v000 | v010; //Because one of these is 0, the or operation takes the max.
SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesY[getDecimatedIndex(x - offset.getX(),y - offset.getY())] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 256)
{
//if(z != regSlice.getUpperCorner.getZ())
{
volIter.setPosition(x,y,z + uStepSize);
const uint8 v001 = volIter.getSubSampledVoxel(uLevel);
const Vector3DFloat v3dPosition(x - offset.getX(), y - offset.getY(), z - offset.getZ() + 0.5f * uStepSize);
const Vector3DFloat v3dNormal(0.0,0.0,v000 > v001 ? 1.0f : -1.0f);
const uint8 uMaterial = v000 | v001; //Because one of these is 0, the or operation takes the max.
const SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesZ[getDecimatedIndex(x - offset.getX(),y - offset.getY())] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
}//For each cell
}
}
void generateDecimatedIndicesForSlice(BlockVolumeIterator<uint8>& volIter, uint8 uLevel, const Region& regSlice, IndexedSurfacePatch* singleMaterialPatch, const Vector3DFloat& offset, uint8* bitmask0, uint8* bitmask1, int32 vertexIndicesX0[],int32 vertexIndicesY0[],int32 vertexIndicesZ0[], int32 vertexIndicesX1[],int32 vertexIndicesY1[],int32 vertexIndicesZ1[])
{
const uint8 uStepSize = uLevel == 0 ? 1 : 1 << uLevel;
uint32 indlist[12];
for(uint16 y = regSlice.getLowerCorner().getY() - offset.getY(); y < regSlice.getUpperCorner().getY() - offset.getY(); y += uStepSize)
{
for(uint16 x = regSlice.getLowerCorner().getX() - offset.getX(); x < regSlice.getUpperCorner().getX() - offset.getX(); x += uStepSize)
{
//Current position
const uint16 z = regSlice.getLowerCorner().getZ() - offset.getZ();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8 iCubeIndex = bitmask0[getDecimatedIndex(x,y)];
/* Cube is entirely in/out of the surface */
if (edgeTable[iCubeIndex] == 0)
{
continue;
}
/* Find the vertices where the surface intersects the cube */
if (edgeTable[iCubeIndex] & 1)
{
indlist[0] = vertexIndicesX0[getDecimatedIndex(x,y)];
assert(indlist[0] != -1);
}
if (edgeTable[iCubeIndex] & 2)
{
indlist[1] = vertexIndicesY0[getDecimatedIndex(x+uStepSize,y)];
assert(indlist[1] != -1);
}
if (edgeTable[iCubeIndex] & 4)
{
indlist[2] = vertexIndicesX0[getDecimatedIndex(x,y+uStepSize)];
assert(indlist[2] != -1);
}
if (edgeTable[iCubeIndex] & 8)
{
indlist[3] = vertexIndicesY0[getDecimatedIndex(x,y)];
assert(indlist[3] != -1);
}
if (edgeTable[iCubeIndex] & 16)
{
indlist[4] = vertexIndicesX1[getDecimatedIndex(x,y)];
assert(indlist[4] != -1);
}
if (edgeTable[iCubeIndex] & 32)
{
indlist[5] = vertexIndicesY1[getDecimatedIndex(x+uStepSize,y)];
assert(indlist[5] != -1);
}
if (edgeTable[iCubeIndex] & 64)
{
indlist[6] = vertexIndicesX1[getDecimatedIndex(x,y+uStepSize)];
assert(indlist[6] != -1);
}
if (edgeTable[iCubeIndex] & 128)
{
indlist[7] = vertexIndicesY1[getDecimatedIndex(x,y)];
assert(indlist[7] != -1);
}
if (edgeTable[iCubeIndex] & 256)
{
indlist[8] = vertexIndicesZ0[getDecimatedIndex(x,y)];
assert(indlist[8] != -1);
}
if (edgeTable[iCubeIndex] & 512)
{
indlist[9] = vertexIndicesZ0[getDecimatedIndex(x+uStepSize,y)];
assert(indlist[9] != -1);
}
if (edgeTable[iCubeIndex] & 1024)
{
indlist[10] = vertexIndicesZ0[getDecimatedIndex(x+uStepSize,y+uStepSize)];
assert(indlist[10] != -1);
}
if (edgeTable[iCubeIndex] & 2048)
{
indlist[11] = vertexIndicesZ0[getDecimatedIndex(x,y+uStepSize)];
assert(indlist[11] != -1);
}
for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
{
uint32 ind0 = indlist[triTable[iCubeIndex][i ]];
uint32 ind1 = indlist[triTable[iCubeIndex][i+1]];
uint32 ind2 = indlist[triTable[iCubeIndex][i+2]];
singleMaterialPatch->m_vecTriangleIndices.push_back(ind0);
singleMaterialPatch->m_vecTriangleIndices.push_back(ind1);
singleMaterialPatch->m_vecTriangleIndices.push_back(ind2);
}//For each triangle
}//For each cell
}
}
void generateDecimatedMeshDataForRegionSlow(BlockVolume<uint8>* volumeData, Region region, IndexedSurfacePatch* singleMaterialPatch)
{
//When generating the mesh for a region we actually look one voxel outside it in the
// back, bottom, right direction. Protect against access violations by cropping region here
Region regVolume = volumeData->getEnclosingRegion();
//regVolume.setUpperCorner(regVolume.getUpperCorner() - Vector3DInt32(1,1,1));
region.cropTo(regVolume);
region.setUpperCorner(region.getUpperCorner() - Vector3DInt32(1,1,1));
//Offset from lower block corner
const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
Vector3DFloat vertlist[12];
Vector3DFloat normlist[12];
uint8 vertMaterials[12];
BlockVolumeIterator<uint8> volIter(*volumeData);
volIter.setValidRegion(region);
//////////////////////////////////////////////////////////////////////////
//Get mesh data
//////////////////////////////////////////////////////////////////////////
//Iterate over each cell in the region
//volIter.setPosition(region.getLowerCorner().getX(),region.getLowerCorner().getY(), region.getLowerCorner().getZ());
for(uint16 z = region.getLowerCorner().getZ(); z <= region.getUpperCorner().getZ(); z += 2)
{
for(uint16 y = region.getLowerCorner().getY(); y <= region.getUpperCorner().getY(); y += 2)
{
for(uint16 x = region.getLowerCorner().getX(); x <= region.getUpperCorner().getX(); x += 2)
{
//while(volIter.moveForwardInRegionXYZ())
//{
volIter.setPosition(x,y,z);
const uint8 v000 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x+2,y,z);
const uint8 v100 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x,y+2,z);
const uint8 v010 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x+2,y+2,z);
const uint8 v110 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x,y,z+2);
const uint8 v001 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x+2,y,z+2);
const uint8 v101 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x,y+2,z+2);
const uint8 v011 = volIter.getSubSampledVoxel(1);
volIter.setPosition(x+2,y+2,z+2);
const uint8 v111 = volIter.getSubSampledVoxel(1);
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8 iCubeIndex = 0;
if (v000 == 0) iCubeIndex |= 1;
if (v100 == 0) iCubeIndex |= 2;
if (v110 == 0) iCubeIndex |= 4;
if (v010 == 0) iCubeIndex |= 8;
if (v001 == 0) iCubeIndex |= 16;
if (v101 == 0) iCubeIndex |= 32;
if (v111 == 0) iCubeIndex |= 64;
if (v011 == 0) iCubeIndex |= 128;
/* Cube is entirely in/out of the surface */
if (edgeTable[iCubeIndex] == 0)
{
continue;
}
/* Find the vertices where the surface intersects the cube */
if (edgeTable[iCubeIndex] & 1)
{
vertlist[0].setX(x + 0.5f * 2.0f);
vertlist[0].setY(y);
vertlist[0].setZ(z);
normlist[0] = Vector3DFloat(v000 - v100,0.0,0.0);
vertMaterials[0] = v000 | v100; //Because one of these is 0, the or operation takes the max.
}
if (edgeTable[iCubeIndex] & 2)
{
vertlist[1].setX(x + 1.0f * 2.0f);
vertlist[1].setY(y + 0.5f * 2.0f);
vertlist[1].setZ(z);
vertMaterials[1] = v100 | v110;
normlist[1] = Vector3DFloat(0.0,v100 - v110,0.0);
}
if (edgeTable[iCubeIndex] & 4)
{
vertlist[2].setX(x + 0.5f * 2.0f);
vertlist[2].setY(y + 1.0f * 2.0f);
vertlist[2].setZ(z);
vertMaterials[2] = v010 | v110;
normlist[2] = Vector3DFloat(v010 - v110,0.0,0.0);
}
if (edgeTable[iCubeIndex] & 8)
{
vertlist[3].setX(x);
vertlist[3].setY(y + 0.5f * 2.0f);
vertlist[3].setZ(z);
vertMaterials[3] = v000 | v010;
normlist[3] = Vector3DFloat(0.0,v000 - v010,0.0);
}
if (edgeTable[iCubeIndex] & 16)
{
vertlist[4].setX(x + 0.5f * 2.0f);
vertlist[4].setY(y);
vertlist[4].setZ(z + 1.0f * 2.0f);
vertMaterials[4] = v001 | v101;
normlist[4] = Vector3DFloat(v001 - v101,0.0,0.0);
}
if (edgeTable[iCubeIndex] & 32)
{
vertlist[5].setX(x + 1.0f * 2.0f);
vertlist[5].setY(y + 0.5f * 2.0f);
vertlist[5].setZ(z + 1.0f * 2.0f);
vertMaterials[5] = v101 | v111;
normlist[5] = Vector3DFloat(0.0,v101 - v111,0.0);
}
if (edgeTable[iCubeIndex] & 64)
{
vertlist[6].setX(x + 0.5f * 2.0f);
vertlist[6].setY(y + 1.0f * 2.0f);
vertlist[6].setZ(z + 1.0f * 2.0f);
vertMaterials[6] = v011 | v111;
normlist[6] = Vector3DFloat(v011 - v111,0.0,0.0);
}
if (edgeTable[iCubeIndex] & 128)
{
vertlist[7].setX(x);
vertlist[7].setY(y + 0.5f * 2.0f);
vertlist[7].setZ(z + 1.0f * 2.0f);
vertMaterials[7] = v001 | v011;
normlist[7] = Vector3DFloat(0.0,v001 - v011,0.0);
}
if (edgeTable[iCubeIndex] & 256)
{
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + 0.5f * 2.0f);
vertMaterials[8] = v000 | v001;
normlist[8] = Vector3DFloat(0.0,0.0,v000 - v001);
}
if (edgeTable[iCubeIndex] & 512)
{
vertlist[9].setX(x + 1.0f * 2.0f);
vertlist[9].setY(y);
vertlist[9].setZ(z + 0.5f * 2.0f);
vertMaterials[9] = v100 | v101;
normlist[9] = Vector3DFloat(0.0,0.0,v100 - v101);
}
if (edgeTable[iCubeIndex] & 1024)
{
vertlist[10].setX(x + 1.0f * 2.0f);
vertlist[10].setY(y + 1.0f * 2.0f);
vertlist[10].setZ(z + 0.5f * 2.0f);
vertMaterials[10] = v110 | v111;
normlist[10] = Vector3DFloat(0.0,0.0,v110 - v111);
}
if (edgeTable[iCubeIndex] & 2048)
{
vertlist[11].setX(x);
vertlist[11].setY(y + 1.0f * 2.0f);
vertlist[11].setZ(z + 0.5f * 2.0f);
vertMaterials[11] = v010 | v011;
normlist[11] = Vector3DFloat(0.0,0.0,v010 - v011);
}
for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
{
//The three vertices forming a triangle
Vector3DFloat vertex0 = vertlist[triTable[iCubeIndex][i ]] - offset;
Vector3DFloat vertex1 = vertlist[triTable[iCubeIndex][i+1]] - offset;
Vector3DFloat vertex2 = vertlist[triTable[iCubeIndex][i+2]] - offset;
Vector3DFloat normal0 = normlist[triTable[iCubeIndex][i ]];
Vector3DFloat normal1 = normlist[triTable[iCubeIndex][i+1]];
Vector3DFloat normal2 = normlist[triTable[iCubeIndex][i+2]];
normal0.normalise();
normal1.normalise();
normal2.normalise();
vertex0 += (normal0);
vertex1 += (normal1);
vertex2 += (normal2);
//Cast to floats and divide by two.
//const Vector3DFloat vertex0AsFloat = (static_cast<Vector3DFloat>(vertex0) / 2.0f) - offset;
//const Vector3DFloat vertex1AsFloat = (static_cast<Vector3DFloat>(vertex1) / 2.0f) - offset;
//const Vector3DFloat vertex2AsFloat = (static_cast<Vector3DFloat>(vertex2) / 2.0f) - offset;
const uint8 material0 = vertMaterials[triTable[iCubeIndex][i ]];
const uint8 material1 = vertMaterials[triTable[iCubeIndex][i+1]];
const uint8 material2 = vertMaterials[triTable[iCubeIndex][i+2]];
//If all the materials are the same, we just need one triangle for that material with all the alphas set high.
SurfaceVertex surfaceVertex0Alpha1(vertex0,material0 + 0.1f);
surfaceVertex0Alpha1.setNormal(normal0);
SurfaceVertex surfaceVertex1Alpha1(vertex1,material1 + 0.1f);
surfaceVertex1Alpha1.setNormal(normal1);
SurfaceVertex surfaceVertex2Alpha1(vertex2,material2 + 0.1f);
surfaceVertex2Alpha1.setNormal(normal2);
singleMaterialPatch->addTriangle(surfaceVertex0Alpha1, surfaceVertex1Alpha1, surfaceVertex2Alpha1);
}//For each triangle
//}//For each cell
}
}
}
//FIXME - can it happen that we have no vertices or triangles? Should exit early?
//for(std::map<uint8, IndexedSurfacePatch*>::iterator iterPatch = surfacePatchMapResult.begin(); iterPatch != surfacePatchMapResult.end(); ++iterPatch)
{
/*std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin();
while(iterSurfaceVertex != singleMaterialPatch->getVertices().end())
{
Vector3DFloat tempNormal = computeNormal(volumeData, static_cast<Vector3DFloat>(iterSurfaceVertex->getPosition() + offset), SIMPLE);
const_cast<SurfaceVertex&>(*iterSurfaceVertex).setNormal(tempNormal);
++iterSurfaceVertex;
}*/
}
}
Vector3DFloat computeDecimatedNormal(BlockVolume<uint8>* volumeData, const Vector3DFloat& position, NormalGenerationMethod normalGenerationMethod)
{
const float posX = position.getX();
const float posY = position.getY();
const float posZ = position.getZ();
const uint16 floorX = static_cast<uint16>(posX);
const uint16 floorY = static_cast<uint16>(posY);
const uint16 floorZ = static_cast<uint16>(posZ);
//Check all corners are within the volume, allowing a boundary for gradient estimation
bool lowerCornerInside = volumeData->containsPoint(Vector3DInt32(floorX, floorY, floorZ),1);
bool upperCornerInside = volumeData->containsPoint(Vector3DInt32(floorX+1, floorY+1, floorZ+1),1);
if((!lowerCornerInside) || (!upperCornerInside))
{
normalGenerationMethod = SIMPLE;
}
Vector3DFloat result;
BlockVolumeIterator<uint8> volIter(*volumeData); //FIXME - save this somewhere - could be expensive to create?
if(normalGenerationMethod == SOBEL)
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY),static_cast<uint16>(posZ));
const Vector3DFloat gradFloor = computeSobelGradient(volIter);
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX+1.0),static_cast<uint16>(posY),static_cast<uint16>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY+1.0),static_cast<uint16>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY),static_cast<uint16>(posZ+1.0));
}
const Vector3DFloat gradCeil = computeSobelGradient(volIter);
result = ((gradFloor + gradCeil) * -1.0f);
if(result.lengthSquared() < 0.0001)
{
//Operation failed - fall back on simple gradient estimation
normalGenerationMethod = SIMPLE;
}
}
if(normalGenerationMethod == CENTRAL_DIFFERENCE)
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY),static_cast<uint16>(posZ));
const Vector3DFloat gradFloor = computeCentralDifferenceGradient(volIter);
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX+1.0),static_cast<uint16>(posY),static_cast<uint16>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY+1.0),static_cast<uint16>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY),static_cast<uint16>(posZ+1.0));
}
const Vector3DFloat gradCeil = computeCentralDifferenceGradient(volIter);
result = ((gradFloor + gradCeil) * -1.0f);
if(result.lengthSquared() < 0.0001)
{
//Operation failed - fall back on simple gradient estimation
normalGenerationMethod = SIMPLE;
}
}
if(normalGenerationMethod == SIMPLE)
{
volIter.setPosition(static_cast<uint16>(posX),static_cast<uint16>(posY),static_cast<uint16>(posZ));
const uint8 uFloor = volIter.getVoxel() > 0 ? 1 : 0;
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
uint8 uCeil = volIter.peekVoxel1px0py0pz() > 0 ? 1 : 0;
result = Vector3DFloat(static_cast<float>(uFloor - uCeil),0.0,0.0);
}
else if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
uint8 uCeil = volIter.peekVoxel0px1py0pz() > 0 ? 1 : 0;
result = Vector3DFloat(0.0,static_cast<float>(uFloor - uCeil),0.0);
}
else if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
uint8 uCeil = volIter.peekVoxel0px0py1pz() > 0 ? 1 : 0;
result = Vector3DFloat(0.0, 0.0,static_cast<float>(uFloor - uCeil));
}
}
return result;
}
}
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