AnotherFoxGuy/polyvox
1
0
Fork 0
Code Issues Pull Requests Activity
polyvox/source/SurfaceExtractors.cpp

1070 lines
41 KiB
C++
Raw Blame History

#include "SurfaceExtractors.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"
using namespace boost;
namespace PolyVox
{
std::list<RegionGeometry> getChangedRegionGeometry(VolumeChangeTracker& volume)
{
std::list<Region> listChangedRegions;
volume.getChangedRegions(listChangedRegions);
std::list<RegionGeometry> listChangedRegionGeometry;
for(std::list<Region>::const_iterator iterChangedRegions = listChangedRegions.begin(); iterChangedRegions != listChangedRegions.end(); ++iterChangedRegions)
{
//Generate the surface
RegionGeometry regionGeometry;
regionGeometry.m_patchSingleMaterial = new IndexedSurfacePatch(false);
regionGeometry.m_v3dRegionPosition = iterChangedRegions->getLowerCorner();
generateExperimentalMeshDataForRegion(volume.getVolumeData(), *iterChangedRegions, regionGeometry.m_patchSingleMaterial);
//genMultiFromSingle(regionGeometry.m_patchSingleMaterial, regionGeometry.m_patchMultiMaterial);
regionGeometry.m_bContainsSingleMaterialPatch = regionGeometry.m_patchSingleMaterial->getVertices().size() > 0;
regionGeometry.m_bIsEmpty = (regionGeometry.m_patchSingleMaterial->getVertices().size() == 0);
listChangedRegionGeometry.push_back(regionGeometry);
}
return listChangedRegionGeometry;
}
void generateExperimentalMeshDataForRegion(BlockVolume<uint8_t>* volumeData, Region region, IndexedSurfacePatch* singleMaterialPatch)
{
singleMaterialPatch->m_vecVertices.clear();
singleMaterialPatch->m_vecTriangleIndices.clear();
//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);
//Offset from region corner
const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
//Cell bitmasks
boost::uint8_t bitmask0[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::uint8_t bitmask1[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
memset(bitmask0, 0x00, sizeof(bitmask0));
memset(bitmask1, 0x00, sizeof(bitmask1));
Region regFirstSlice(region);
regFirstSlice.setUpperCorner(Vector3DInt32(regFirstSlice.getUpperCorner().getX(),regFirstSlice.getUpperCorner().getY(),regFirstSlice.getLowerCorner().getZ()));
BlockVolumeIterator<boost::uint8_t> volIter(*volumeData);
computeBitmaskForSlice(volIter, regFirstSlice, offset, bitmask0);
for(boost::uint32_t uSlice = 0; ((uSlice <= 15) && (uSlice + offset.getZ() < region.getUpperCorner().getZ())); ++uSlice)
{
Vector3DInt32 lowerCorner = Vector3DInt32(region.getLowerCorner().getX(), region.getLowerCorner().getY(), region.getLowerCorner().getZ() + uSlice);
Vector3DInt32 upperCorner = Vector3DInt32(region.getUpperCorner().getX(), region.getUpperCorner().getY(), region.getLowerCorner().getZ() + uSlice + 1);
Region regTwoSlice(lowerCorner, upperCorner);
Region regSecondSlice(regTwoSlice);
regSecondSlice.setLowerCorner(regSecondSlice.getLowerCorner() + Vector3DInt32(0,0,1));
computeBitmaskForSlice(volIter, regSecondSlice, offset, bitmask1);
generateExperimentalMeshDataForRegionSlice(volIter, regTwoSlice, singleMaterialPatch, offset, bitmask0, bitmask1);
memcpy(bitmask0, bitmask1, sizeof(bitmask0));
memset(bitmask1, 0, sizeof(bitmask1));
}
std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin();
while(iterSurfaceVertex != singleMaterialPatch->getVertices().end())
{
Vector3DFloat tempNormal = computeNormal(volumeData, static_cast<Vector3DFloat>(iterSurfaceVertex->getPosition() + offset), CENTRAL_DIFFERENCE);
const_cast<SurfaceVertex&>(*iterSurfaceVertex).setNormal(tempNormal);
++iterSurfaceVertex;
}
}
void generateExperimentalMeshDataForRegionSlice(BlockVolumeIterator<uint8_t>& volIter, Region regTwoSlice, IndexedSurfacePatch* singleMaterialPatch, const Vector3DFloat& offset, uint8_t bitmask0[][POLYVOX_REGION_SIDE_LENGTH+1], uint8_t bitmask1[][POLYVOX_REGION_SIDE_LENGTH+1])
{
//For edge indices
boost::int32_t vertexIndicesX0[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::int32_t vertexIndicesY0[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::int32_t vertexIndicesZ0[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::int32_t vertexIndicesX1[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::int32_t vertexIndicesY1[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
boost::int32_t vertexIndicesZ1[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
memset(vertexIndicesX0,0xFF,sizeof(vertexIndicesX0)); //0xFF is -1 as two's complement - this may not be portable...
memset(vertexIndicesY0,0xFF,sizeof(vertexIndicesY0));
memset(vertexIndicesZ0,0xFF,sizeof(vertexIndicesZ0));
memset(vertexIndicesX1,0xFF,sizeof(vertexIndicesX1)); //0xFF is -1 as two's complement - this may not be portable...
memset(vertexIndicesY1,0xFF,sizeof(vertexIndicesY1));
memset(vertexIndicesZ1,0xFF,sizeof(vertexIndicesZ1));
Region regFirstSlice(regTwoSlice);
regFirstSlice.setUpperCorner(regFirstSlice.getUpperCorner() - Vector3DInt32(0,0,1));
Region regSecondSlice(regTwoSlice);
regSecondSlice.setLowerCorner(regSecondSlice.getLowerCorner() + Vector3DInt32(0,0,1));
//////////////////////////////////////////////////////////////////////////
//Generate vertices
//////////////////////////////////////////////////////////////////////////
Vector3DFloat vertlist[12];
uint8_t vertMaterials[12];
generateVerticesForSlice(volIter,regFirstSlice, offset, bitmask0, singleMaterialPatch, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0, regTwoSlice.getUpperCorner(), vertlist, vertMaterials);
generateVerticesForSlice(volIter,regSecondSlice, offset, bitmask1, singleMaterialPatch, vertexIndicesX1, vertexIndicesY1, vertexIndicesZ1, regTwoSlice.getUpperCorner(), vertlist, vertMaterials);
#ifdef BLAH
//Iterate over each cell in the region
volIter.setPosition(regFirstSlice.getLowerCorner().getX(),regFirstSlice.getLowerCorner().getY(), regFirstSlice.getLowerCorner().getZ());
volIter.setValidRegion(regFirstSlice);
//while(volIter.moveForwardInRegionXYZ())
do
{
//Current position
const uint16_t x = volIter.getPosX() - offset.getX();
const uint16_t y = volIter.getPosY() - offset.getY();
const uint16_t z = volIter.getPosZ() - offset.getZ();
const uint8_t v000 = volIter.getVoxel();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask0[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)
{
if((x + offset.getX()) != regTwoSlice.getUpperCorner().getX())
{
vertlist[0].setX(x + 0.5f);
vertlist[0].setY(y);
vertlist[0].setZ(z);
vertMaterials[0] = v000 | volIter.peekVoxel1px0py0pz(); //Because one of these is 0, the or operation takes the max.
SurfaceVertex surfaceVertex(vertlist[0],vertMaterials[0], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesX0[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 8)
{
if((y + offset.getY()) != regTwoSlice.getUpperCorner().getY())
{
vertlist[3].setX(x);
vertlist[3].setY(y + 0.5f);
vertlist[3].setZ(z);
vertMaterials[3] = v000 | volIter.peekVoxel0px1py0pz();
SurfaceVertex surfaceVertex(vertlist[3],vertMaterials[3], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesY0[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 256)
{
if((z + offset.getZ()) != regTwoSlice.getUpperCorner().getZ())
{
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + 0.5f);
vertMaterials[8] = v000 | volIter.peekVoxel0px0py1pz();
SurfaceVertex surfaceVertex(vertlist[8],vertMaterials[8], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesZ0[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
}while(volIter.moveForwardInRegionXYZ());//For each cell
//Iterate over each cell in the region
volIter.setPosition(regSecondSlice.getLowerCorner().getX(),regSecondSlice.getLowerCorner().getY(), regSecondSlice.getLowerCorner().getZ());
volIter.setValidRegion(regSecondSlice);
//while(volIter.moveForwardInRegionXYZ())
do
{
//Current position
const uint16_t x = volIter.getPosX() - offset.getX();
const uint16_t y = volIter.getPosY() - offset.getY();
const uint16_t z = volIter.getPosZ() - offset.getZ();
const uint8_t v000 = volIter.getVoxel();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask1[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)
{
if((x + offset.getX()) != regTwoSlice.getUpperCorner().getX())
{
vertlist[0].setX(x + 0.5f);
vertlist[0].setY(y);
vertlist[0].setZ(z);
vertMaterials[0] = v000 | volIter.peekVoxel1px0py0pz(); //Because one of these is 0, the or operation takes the max.
SurfaceVertex surfaceVertex(vertlist[0],vertMaterials[0], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesX1[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 8)
{
if((y + offset.getY()) != regTwoSlice.getUpperCorner().getY())
{
vertlist[3].setX(x);
vertlist[3].setY(y + 0.5f);
vertlist[3].setZ(z);
vertMaterials[3] = v000 | volIter.peekVoxel0px1py0pz();
SurfaceVertex surfaceVertex(vertlist[3],vertMaterials[3], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesY1[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 256)
{
if((z + offset.getZ()) != regTwoSlice.getUpperCorner().getZ())
{
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + 0.5f);
vertMaterials[8] = v000 | volIter.peekVoxel0px0py1pz();
SurfaceVertex surfaceVertex(vertlist[8],vertMaterials[8], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesZ1[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
}while(volIter.moveForwardInRegionXYZ());//For each cell
#endif
//////////////////////////////////////////////////////////////
// Set the indices
//////////////////////////////////////////////////////////////
boost::uint32_t indlist[12];
//Iterate over each cell in the region
regFirstSlice.setUpperCorner(regFirstSlice.getUpperCorner() - Vector3DInt32(1,1,0));
volIter.setPosition(regFirstSlice.getLowerCorner().getX(),regFirstSlice.getLowerCorner().getY(), regFirstSlice.getLowerCorner().getZ());
volIter.setValidRegion(regFirstSlice);
//while(volIter.moveForwardInRegionXYZ())
do
{
//Current position
const uint16_t x = volIter.getPosX() - offset.getX();
const uint16_t y = volIter.getPosY() - offset.getY();
const uint16_t z = volIter.getPosZ() - offset.getZ();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask0[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[x][y];
assert(indlist[0] != -1);
}
if (edgeTable[iCubeIndex] & 2)
{
indlist[1] = vertexIndicesY0[x+1][y];
assert(indlist[1] != -1);
}
if (edgeTable[iCubeIndex] & 4)
{
indlist[2] = vertexIndicesX0[x][y+1];
assert(indlist[2] != -1);
}
if (edgeTable[iCubeIndex] & 8)
{
indlist[3] = vertexIndicesY0[x][y];
assert(indlist[3] != -1);
}
if (edgeTable[iCubeIndex] & 16)
{
indlist[4] = vertexIndicesX1[x][y];
assert(indlist[4] != -1);
}
if (edgeTable[iCubeIndex] & 32)
{
indlist[5] = vertexIndicesY1[x+1][y];
assert(indlist[5] != -1);
}
if (edgeTable[iCubeIndex] & 64)
{
indlist[6] = vertexIndicesX1[x][y+1];
assert(indlist[6] != -1);
}
if (edgeTable[iCubeIndex] & 128)
{
indlist[7] = vertexIndicesY1[x][y];
assert(indlist[7] != -1);
}
if (edgeTable[iCubeIndex] & 256)
{
indlist[8] = vertexIndicesZ0[x][y];
assert(indlist[8] != -1);
}
if (edgeTable[iCubeIndex] & 512)
{
indlist[9] = vertexIndicesZ0[x+1][y];
assert(indlist[9] != -1);
}
if (edgeTable[iCubeIndex] & 1024)
{
indlist[10] = vertexIndicesZ0[x+1][y+1];
assert(indlist[10] != -1);
}
if (edgeTable[iCubeIndex] & 2048)
{
indlist[11] = vertexIndicesZ0[x][y+1];
assert(indlist[11] != -1);
}
for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
{
boost::uint32_t ind0 = indlist[triTable[iCubeIndex][i ]];
boost::uint32_t ind1 = indlist[triTable[iCubeIndex][i+1]];
boost::uint32_t 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
}while(volIter.moveForwardInRegionXYZ());//For each cell
}
void computeBitmaskForSlice(BlockVolumeIterator<uint8_t>& volIter, Region& regSlice, const Vector3DFloat& offset, uint8_t bitmask[][POLYVOX_REGION_SIDE_LENGTH+1])
{
//Iterate over each cell in the region
volIter.setPosition(regSlice.getLowerCorner().getX(),regSlice.getLowerCorner().getY(), regSlice.getLowerCorner().getZ());
volIter.setValidRegion(regSlice);
do
//while(volIter.moveForwardInRegionXYZ())
{
//Current position
const uint16_t x = volIter.getPosX() - offset.getX();
const uint16_t y = volIter.getPosY() - offset.getY();
const uint16_t z = volIter.getPosZ() - offset.getZ();
//Voxels values
const uint8_t v000 = volIter.getVoxel();
const uint8_t v100 = volIter.peekVoxel1px0py0pz();
const uint8_t v010 = volIter.peekVoxel0px1py0pz();
const uint8_t v110 = volIter.peekVoxel1px1py0pz();
const uint8_t v001 = volIter.peekVoxel0px0py1pz();
const uint8_t v101 = volIter.peekVoxel1px0py1pz();
const uint8_t v011 = volIter.peekVoxel0px1py1pz();
const uint8_t v111 = volIter.peekVoxel1px1py1pz();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t 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;
//Save the bitmask
bitmask[x][y] = iCubeIndex;
}while(volIter.moveForwardInRegionXYZ());//For each cell
}
void generateVerticesForSlice(BlockVolumeIterator<uint8_t>& volIter, Region& regSlice, const Vector3DFloat& offset, uint8_t bitmask[][POLYVOX_REGION_SIDE_LENGTH+1], IndexedSurfacePatch* singleMaterialPatch,boost::int32_t vertexIndicesX[][POLYVOX_REGION_SIDE_LENGTH+1],boost::int32_t vertexIndicesY[][POLYVOX_REGION_SIDE_LENGTH+1],boost::int32_t vertexIndicesZ[][POLYVOX_REGION_SIDE_LENGTH+1], const Vector3DInt32& upperCorner, Vector3DFloat vertlist[], uint8_t vertMaterials[])
{
//Vector3DFloat vertlist[12];
//uint8_t vertMaterials[12];
//Iterate over each cell in the region
volIter.setPosition(regSlice.getLowerCorner().getX(),regSlice.getLowerCorner().getY(), regSlice.getLowerCorner().getZ());
volIter.setValidRegion(regSlice);
//while(volIter.moveForwardInRegionXYZ())
do
{
//Current position
const uint16_t x = volIter.getPosX() - offset.getX();
const uint16_t y = volIter.getPosY() - offset.getY();
const uint16_t z = volIter.getPosZ() - offset.getZ();
const uint8_t v000 = volIter.getVoxel();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask[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)
{
if((x + offset.getX()) != upperCorner.getX())
{
vertlist[0].setX(x + 0.5f);
vertlist[0].setY(y);
vertlist[0].setZ(z);
vertMaterials[0] = v000 | volIter.peekVoxel1px0py0pz(); //Because one of these is 0, the or operation takes the max.
SurfaceVertex surfaceVertex(vertlist[0],vertMaterials[0], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesX[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 8)
{
if((y + offset.getY()) != upperCorner.getY())
{
vertlist[3].setX(x);
vertlist[3].setY(y + 0.5f);
vertlist[3].setZ(z);
vertMaterials[3] = v000 | volIter.peekVoxel0px1py0pz();
SurfaceVertex surfaceVertex(vertlist[3],vertMaterials[3], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesY[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
if (edgeTable[iCubeIndex] & 256)
{
if((z + offset.getZ()) != upperCorner.getZ())
{
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + 0.5f);
vertMaterials[8] = v000 | volIter.peekVoxel0px0py1pz();
SurfaceVertex surfaceVertex(vertlist[8],vertMaterials[8], 1.0);
singleMaterialPatch->m_vecVertices.push_back(surfaceVertex);
vertexIndicesZ[x][y] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
}while(volIter.moveForwardInRegionXYZ());//For each cell
}
void generateRoughMeshDataForRegion(BlockVolume<uint8_t>* 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];
uint8_t vertMaterials[12];
BlockVolumeIterator<boost::uint8_t> 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());
while(volIter.moveForwardInRegionXYZ())
{
//Current position
const uint16_t x = volIter.getPosX();
const uint16_t y = volIter.getPosY();
const uint16_t z = volIter.getPosZ();
//Voxels values
const uint8_t v000 = volIter.getVoxel();
const uint8_t v100 = volIter.peekVoxel1px0py0pz();
const uint8_t v010 = volIter.peekVoxel0px1py0pz();
const uint8_t v110 = volIter.peekVoxel1px1py0pz();
const uint8_t v001 = volIter.peekVoxel0px0py1pz();
const uint8_t v101 = volIter.peekVoxel1px0py1pz();
const uint8_t v011 = volIter.peekVoxel0px1py1pz();
const uint8_t v111 = volIter.peekVoxel1px1py1pz();
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t 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);
vertlist[0].setY(y);
vertlist[0].setZ(z);
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);
vertlist[1].setY(y + 0.5f);
vertlist[1].setZ(z);
vertMaterials[1] = v100 | v110;
}
if (edgeTable[iCubeIndex] & 4)
{
vertlist[2].setX(x + 0.5f);
vertlist[2].setY(y + 1.0f);
vertlist[2].setZ(z);
vertMaterials[2] = v010 | v110;
}
if (edgeTable[iCubeIndex] & 8)
{
vertlist[3].setX(x);
vertlist[3].setY(y + 0.5f);
vertlist[3].setZ(z);
vertMaterials[3] = v000 | v010;
}
if (edgeTable[iCubeIndex] & 16)
{
vertlist[4].setX(x + 0.5f);
vertlist[4].setY(y);
vertlist[4].setZ(z + 1.0f);
vertMaterials[4] = v001 | v101;
}
if (edgeTable[iCubeIndex] & 32)
{
vertlist[5].setX(x + 1.0f);
vertlist[5].setY(y + 0.5f);
vertlist[5].setZ(z + 1.0f);
vertMaterials[5] = v101 | v111;
}
if (edgeTable[iCubeIndex] & 64)
{
vertlist[6].setX(x + 0.5f);
vertlist[6].setY(y + 1.0f);
vertlist[6].setZ(z + 1.0f);
vertMaterials[6] = v011 | v111;
}
if (edgeTable[iCubeIndex] & 128)
{
vertlist[7].setX(x);
vertlist[7].setY(y + 0.5f);
vertlist[7].setZ(z + 1.0f);
vertMaterials[7] = v001 | v011;
}
if (edgeTable[iCubeIndex] & 256)
{
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + 0.5f);
vertMaterials[8] = v000 | v001;
}
if (edgeTable[iCubeIndex] & 512)
{
vertlist[9].setX(x + 1.0f);
vertlist[9].setY(y);
vertlist[9].setZ(z + 0.5f);
vertMaterials[9] = v100 | v101;
}
if (edgeTable[iCubeIndex] & 1024)
{
vertlist[10].setX(x + 1.0f);
vertlist[10].setY(y + 1.0f);
vertlist[10].setZ(z + 0.5f);
vertMaterials[10] = v110 | v111;
}
if (edgeTable[iCubeIndex] & 2048)
{
vertlist[11].setX(x);
vertlist[11].setY(y + 1.0f);
vertlist[11].setZ(z + 0.5f);
vertMaterials[11] = v010 | v011;
}
for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
{
//The three vertices forming a triangle
const Vector3DFloat vertex0 = vertlist[triTable[iCubeIndex][i ]] - offset;
const Vector3DFloat vertex1 = vertlist[triTable[iCubeIndex][i+1]] - offset;
const Vector3DFloat vertex2 = vertlist[triTable[iCubeIndex][i+2]] - offset;
//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_t material0 = vertMaterials[triTable[iCubeIndex][i ]];
const uint8_t material1 = vertMaterials[triTable[iCubeIndex][i+1]];
const uint8_t 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,1.0f);
SurfaceVertex surfaceVertex1Alpha1(vertex1,material1 + 0.1f,1.0f);
SurfaceVertex surfaceVertex2Alpha1(vertex2,material2 + 0.1f,1.0f);
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_t, 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), CENTRAL_DIFFERENCE);
const_cast<SurfaceVertex&>(*iterSurfaceVertex).setNormal(tempNormal);
++iterSurfaceVertex;
}
}
}
Vector3DFloat computeNormal(BlockVolume<uint8_t>* volumeData, const Vector3DFloat& position, NormalGenerationMethod normalGenerationMethod)
{
const float posX = position.getX();
const float posY = position.getY();
const float posZ = position.getZ();
const uint16_t floorX = static_cast<uint16_t>(posX);
const uint16_t floorY = static_cast<uint16_t>(posY);
const uint16_t floorZ = static_cast<uint16_t>(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<boost::uint8_t> volIter(*volumeData); //FIXME - save this somewhere - could be expensive to create?
if(normalGenerationMethod == SOBEL)
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX+1.0),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY+1.0),static_cast<uint16_t>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX+1.0),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY+1.0),static_cast<uint16_t>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
const uint8_t uFloor = volIter.getVoxel() > 0 ? 1 : 0;
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
uint8_t 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_t 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_t uCeil = volIter.peekVoxel0px0py1pz() > 0 ? 1 : 0;
result = Vector3DFloat(0.0, 0.0,static_cast<float>(uFloor - uCeil));
}
}
return result;
}
void generateSmoothMeshDataForRegion(BlockVolume<uint8_t>* 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);
//Offset from lower block corner
const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
Vector3DFloat vertlist[12];
uint8_t vertMaterials[12];
BlockVolumeIterator<boost::uint8_t> volIter(*volumeData);
volIter.setValidRegion(region);
const float threshold = 0.5f;
//////////////////////////////////////////////////////////////////////////
//Get mesh data
//////////////////////////////////////////////////////////////////////////
//Iterate over each cell in the region
for(volIter.setPosition(region.getLowerCorner().getX(),region.getLowerCorner().getY(), region.getLowerCorner().getZ());volIter.isValidForRegion();volIter.moveForwardInRegionXYZ())
{
//Current position
const uint16_t x = volIter.getPosX();
const uint16_t y = volIter.getPosY();
const uint16_t z = volIter.getPosZ();
//Voxels values
BlockVolumeIterator<boost::uint8_t> tempVolIter(*volumeData);
tempVolIter.setPosition(x,y,z);
const float v000 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x+1,y,z);
const float v100 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x,y+1,z);
const float v010 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x+1,y+1,z);
const float v110 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x,y,z+1);
const float v001 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x+1,y,z+1);
const float v101 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x,y+1,z+1);
const float v011 = tempVolIter.getAveragedVoxel(1);
tempVolIter.setPosition(x+1,y+1,z+1);
const float v111 = tempVolIter.getAveragedVoxel(1);
//Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = 0;
if (v000 < threshold) iCubeIndex |= 1;
if (v100 < threshold) iCubeIndex |= 2;
if (v110 < threshold) iCubeIndex |= 4;
if (v010 < threshold) iCubeIndex |= 8;
if (v001 < threshold) iCubeIndex |= 16;
if (v101 < threshold) iCubeIndex |= 32;
if (v111 < threshold) iCubeIndex |= 64;
if (v011 < threshold) 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)
{
float a = v000;
float b = v100;
float val = (threshold-a)/(b-a);
vertlist[0].setX(x + val);
vertlist[0].setY(y);
vertlist[0].setZ(z);
vertMaterials[0] = 1;//v000 | v100; //Because one of these is 0, the or operation takes the max.
}
if (edgeTable[iCubeIndex] & 2)
{
float a = v100;
float b = v110;
float val = (threshold-a)/(b-a);
vertlist[1].setX(x + 1.0f);
vertlist[1].setY(y + val);
vertlist[1].setZ(z);
vertMaterials[1] = 1;//v100 | v110;
}
if (edgeTable[iCubeIndex] & 4)
{
float a = v010;
float b = v110;
float val = (threshold-a)/(b-a);
vertlist[2].setX(x + val);
vertlist[2].setY(y + 1.0f);
vertlist[2].setZ(z);
vertMaterials[2] = 1;//v010 | v110;
}
if (edgeTable[iCubeIndex] & 8)
{
float a = v000;
float b = v010;
float val = (threshold-a)/(b-a);
vertlist[3].setX(x);
vertlist[3].setY(y + val);
vertlist[3].setZ(z);
vertMaterials[3] = 1;//v000 | v010;
}
if (edgeTable[iCubeIndex] & 16)
{
float a = v001;
float b = v101;
float val = (threshold-a)/(b-a);
vertlist[4].setX(x + val);
vertlist[4].setY(y);
vertlist[4].setZ(z + 1.0f);
vertMaterials[4] = 1;//v001 | v101;
}
if (edgeTable[iCubeIndex] & 32)
{
float a = v101;
float b = v111;
float val = (threshold-a)/(b-a);
vertlist[5].setX(x + 1.0f);
vertlist[5].setY(y + val);
vertlist[5].setZ(z + 1.0f);
vertMaterials[5] = 1;//v101 | v111;
}
if (edgeTable[iCubeIndex] & 64)
{
float a = v011;
float b = v111;
float val = (threshold-a)/(b-a);
vertlist[6].setX(x + val);
vertlist[6].setY(y + 1.0f);
vertlist[6].setZ(z + 1.0f);
vertMaterials[6] = 1;//v011 | v111;
}
if (edgeTable[iCubeIndex] & 128)
{
float a = v001;
float b = v011;
float val = (threshold-a)/(b-a);
vertlist[7].setX(x);
vertlist[7].setY(y + val);
vertlist[7].setZ(z + 1.0f);
vertMaterials[7] = 1;//v001 | v011;
}
if (edgeTable[iCubeIndex] & 256)
{
float a = v000;
float b = v001;
float val = (threshold-a)/(b-a);
vertlist[8].setX(x);
vertlist[8].setY(y);
vertlist[8].setZ(z + val);
vertMaterials[8] = 1;//v000 | v001;
}
if (edgeTable[iCubeIndex] & 512)
{
float a = v100;
float b = v101;
float val = (threshold-a)/(b-a);
vertlist[9].setX(x + 1.0f);
vertlist[9].setY(y);
vertlist[9].setZ(z + val);
vertMaterials[9] = 1;//v100 | v101;
}
if (edgeTable[iCubeIndex] & 1024)
{
float a = v110;
float b = v111;
float val = (threshold-a)/(b-a);
vertlist[10].setX(x + 1.0f);
vertlist[10].setY(y + 1.0f);
vertlist[10].setZ(z + val);
vertMaterials[10] = 1;//v110 | v111;
}
if (edgeTable[iCubeIndex] & 2048)
{
float a = v010;
float b = v011;
float val = (threshold-a)/(b-a);
vertlist[11].setX(x);
vertlist[11].setY(y + 1.0f);
vertlist[11].setZ(z + val);
vertMaterials[11] = 1;//v010 | v011;
}
for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
{
//The three vertices forming a triangle
const Vector3DFloat vertex0 = vertlist[triTable[iCubeIndex][i ]] - offset;
const Vector3DFloat vertex1 = vertlist[triTable[iCubeIndex][i+1]] - offset;
const Vector3DFloat vertex2 = vertlist[triTable[iCubeIndex][i+2]] - offset;
const uint8_t material0 = vertMaterials[triTable[iCubeIndex][i ]];
const uint8_t material1 = vertMaterials[triTable[iCubeIndex][i+1]];
const uint8_t material2 = vertMaterials[triTable[iCubeIndex][i+2]];
SurfaceVertex surfaceVertex0Alpha1(vertex0,material0 + 0.1f,1.0f);
SurfaceVertex surfaceVertex1Alpha1(vertex1,material1 + 0.1f,1.0f);
SurfaceVertex surfaceVertex2Alpha1(vertex2,material2 + 0.1f,1.0f);
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_t, IndexedSurfacePatch*>::iterator iterPatch = surfacePatchMapResult.begin(); iterPatch != surfacePatchMapResult.end(); ++iterPatch)
{
std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin();
while(iterSurfaceVertex != singleMaterialPatch->getVertices().end())
{
Vector3DFloat tempNormal = computeSmoothNormal(volumeData, static_cast<Vector3DFloat>(iterSurfaceVertex->getPosition() + offset), CENTRAL_DIFFERENCE);
const_cast<SurfaceVertex&>(*iterSurfaceVertex).setNormal(tempNormal);
++iterSurfaceVertex;
}
}
}
Vector3DFloat computeSmoothNormal(BlockVolume<uint8_t>* volumeData, const Vector3DFloat& position, NormalGenerationMethod normalGenerationMethod)
{
const float posX = position.getX();
const float posY = position.getY();
const float posZ = position.getZ();
const uint16_t floorX = static_cast<uint16_t>(posX);
const uint16_t floorY = static_cast<uint16_t>(posY);
const uint16_t floorZ = static_cast<uint16_t>(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<boost::uint8_t> volIter(*volumeData); //FIXME - save this somewhere - could be expensive to create?
if(normalGenerationMethod == SOBEL)
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX+1.0),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY+1.0),static_cast<uint16_t>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(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_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
const Vector3DFloat gradFloor = computeSmoothCentralDifferenceGradient(volIter);
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX+1.0),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
}
if((posY - floorY) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY+1.0),static_cast<uint16_t>(posZ));
}
if((posZ - floorZ) > 0.25) //The result should be 0.0 or 0.5
{
volIter.setPosition(static_cast<uint16_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ+1.0));
}
const Vector3DFloat gradCeil = computeSmoothCentralDifferenceGradient(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_t>(posX),static_cast<uint16_t>(posY),static_cast<uint16_t>(posZ));
const uint8_t uFloor = volIter.getVoxel() > 0 ? 1 : 0;
if((posX - floorX) > 0.25) //The result should be 0.0 or 0.5
{
uint8_t 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_t 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_t uCeil = volIter.peekVoxel0px0py1pz() > 0 ? 1 : 0;
result = Vector3DFloat(0.0, 0.0,static_cast<float>(uFloor - uCeil));
}
}
return result;
}
}
Reference in New Issue View Git Blame Copy Permalink