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More work on experimental marching cubes implementation.

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This commit is contained in:
David Williams 2008-06-04 21:22:02 +00:00
parent c0afd9d77f
commit 1c23f2d1dd
1 changed files with 119 additions and 30 deletions
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149
source/SurfaceExtractors.cpp
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@ -56,23 +56,6 @@ namespace PolyVox
BlockVolumeIterator<boost::uint8_t> volIter(*volumeData); BlockVolumeIterator<boost::uint8_t> volIter(*volumeData);
//std::vector<boost::uint32_t> vecTriangleIndices;
//std::vector<SurfaceVertex> vecVertices;
/*Region regTwoSlice(region);
Vector3DInt32 upperCorner = regTwoSlice.getUpperCorner();
upperCorner.setZ(regTwoSlice.getLowerCorner().getZ() + 1);
regTwoSlice.setUpperCorner(upperCorner);
generateExperimentalMeshDataForRegionSlice(volIter, regTwoSlice, singleMaterialPatch, offset);
regTwoSlice.setLowerCorner(regTwoSlice.getLowerCorner() + Vector3DInt32(0,0,1));
regTwoSlice.setUpperCorner(regTwoSlice.getUpperCorner() + Vector3DInt32(0,0,1));
generateExperimentalMeshDataForRegionSlice(volIter, regTwoSlice, singleMaterialPatch, offset);*/
for(boost::uint32_t uSlice = 0; ((uSlice <= 15) && (uSlice + offset.getZ() < region.getUpperCorner().getZ())); ++uSlice) 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 lowerCorner = Vector3DInt32(region.getLowerCorner().getX(), region.getLowerCorner().getY(), region.getLowerCorner().getZ() + uSlice);
@ -81,11 +64,6 @@ namespace PolyVox
generateExperimentalMeshDataForRegionSlice(volIter, regTwoSlice, singleMaterialPatch, offset); generateExperimentalMeshDataForRegionSlice(volIter, regTwoSlice, singleMaterialPatch, offset);
} }
//FIXME - can it happen that we have no vertices or triangles? Should exit early?
//singleMaterialPatch->m_vecVertices = vecVertices;
//singleMaterialPatch->m_vecTriangleIndices = vecTriangleIndices;
std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin(); std::vector<SurfaceVertex>::iterator iterSurfaceVertex = singleMaterialPatch->getVertices().begin();
while(iterSurfaceVertex != singleMaterialPatch->getVertices().end()) while(iterSurfaceVertex != singleMaterialPatch->getVertices().end())
@ -107,16 +85,21 @@ namespace PolyVox
memset(vertexIndicesZ,0xFF,sizeof(vertexIndicesZ)); memset(vertexIndicesZ,0xFF,sizeof(vertexIndicesZ));
//Cell bitmasks //Cell bitmasks
boost::uint8_t bitmask[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1]; boost::uint8_t bitmask[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][2];
memset(bitmask, 0x00, sizeof(bitmask)); memset(bitmask, 0x00, sizeof(bitmask));
Region regFirstSlice(regTwoSlice);
regFirstSlice.setUpperCorner(regFirstSlice.getUpperCorner() - Vector3DInt32(0,0,1));
Region regSecondSlice(regTwoSlice);
regSecondSlice.setLowerCorner(regSecondSlice.getLowerCorner() + Vector3DInt32(0,0,1));
////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////
// Compute bitmasks // Compute bitmasks
////////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////////
//Iterate over each cell in the region //Iterate over each cell in the region
volIter.setPosition(regTwoSlice.getLowerCorner().getX(),regTwoSlice.getLowerCorner().getY(), regTwoSlice.getLowerCorner().getZ()); volIter.setPosition(regFirstSlice.getLowerCorner().getX(),regFirstSlice.getLowerCorner().getY(), regFirstSlice.getLowerCorner().getZ());
volIter.setValidRegion(regTwoSlice); volIter.setValidRegion(regFirstSlice);
do do
//while(volIter.moveForwardInRegionXYZ()) //while(volIter.moveForwardInRegionXYZ())
{ {
@ -148,7 +131,45 @@ namespace PolyVox
if (v011 == 0) iCubeIndex |= 128; if (v011 == 0) iCubeIndex |= 128;
//Save the bitmask //Save the bitmask
bitmask[x][y][z] = iCubeIndex; bitmask[x][y][0] = iCubeIndex;
}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);
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][1] = iCubeIndex;
}while(volIter.moveForwardInRegionXYZ());//For each cell }while(volIter.moveForwardInRegionXYZ());//For each cell
@ -160,8 +181,8 @@ namespace PolyVox
uint8_t vertMaterials[12]; uint8_t vertMaterials[12];
//Iterate over each cell in the region //Iterate over each cell in the region
volIter.setPosition(regTwoSlice.getLowerCorner().getX(),regTwoSlice.getLowerCorner().getY(), regTwoSlice.getLowerCorner().getZ()); volIter.setPosition(regFirstSlice.getLowerCorner().getX(),regFirstSlice.getLowerCorner().getY(), regFirstSlice.getLowerCorner().getZ());
volIter.setValidRegion(regTwoSlice); volIter.setValidRegion(regFirstSlice);
//while(volIter.moveForwardInRegionXYZ()) //while(volIter.moveForwardInRegionXYZ())
do do
{ {
@ -173,7 +194,7 @@ namespace PolyVox
const uint8_t v000 = volIter.getVoxel(); const uint8_t v000 = volIter.getVoxel();
//Determine the index into the edge table which tells us which vertices are inside of the surface //Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask[x][y][z]; uint8_t iCubeIndex = bitmask[x][y][0];
/* Cube is entirely in/out of the surface */ /* Cube is entirely in/out of the surface */
if (edgeTable[iCubeIndex] == 0) if (edgeTable[iCubeIndex] == 0)
@ -223,6 +244,74 @@ namespace PolyVox
} }
}while(volIter.moveForwardInRegionXYZ());//For each cell }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 = bitmask[x][y][1];
/* 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);
vertexIndicesX[x][y][z] = 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);
vertexIndicesY[x][y][z] = 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);
vertexIndicesZ[x][y][z] = singleMaterialPatch->m_vecVertices.size()-1;
}
}
}while(volIter.moveForwardInRegionXYZ());//For each cell
//////////////////////////////////////////////////////////////
// Set the indices
//////////////////////////////////////////////////////////////
boost::uint32_t indlist[12]; boost::uint32_t indlist[12];
//Iterate over each cell in the region //Iterate over each cell in the region
regTwoSlice.setUpperCorner(regTwoSlice.getUpperCorner() - Vector3DInt32(1,1,1)); regTwoSlice.setUpperCorner(regTwoSlice.getUpperCorner() - Vector3DInt32(1,1,1));
@ -237,7 +326,7 @@ namespace PolyVox
const uint16_t z = volIter.getPosZ() - offset.getZ(); 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 //Determine the index into the edge table which tells us which vertices are inside of the surface
uint8_t iCubeIndex = bitmask[x][y][z]; uint8_t iCubeIndex = bitmask[x][y][0];
/* Cube is entirely in/out of the surface */ /* Cube is entirely in/out of the surface */
if (edgeTable[iCubeIndex] == 0) if (edgeTable[iCubeIndex] == 0)