543 lines
19 KiB
C++
543 lines
19 KiB
C++
#pragma region License
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/******************************************************************************
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This file is part of the PolyVox library
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Copyright (C) 2006 David Williams
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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******************************************************************************/
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#pragma endregion
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#include "PolyVoxCore/PolyVoxImpl/FastSurfaceExtractor.h"
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#include "PolyVoxCore/VolumeIterator.h"
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#include "PolyVoxCore/IndexedSurfacePatch.h"
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#include "PolyVoxCore/MarchingCubesTables.h"
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#include "PolyVoxCore/SurfaceVertex.h"
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namespace PolyVox
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{
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void extractFastSurfaceImpl(Volume<uint8>* volumeData, Region region, IndexedSurfacePatch* singleMaterialPatch)
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{
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singleMaterialPatch->clear();
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//For edge indices
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int32* vertexIndicesX0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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int32* vertexIndicesY0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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int32* vertexIndicesZ0 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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int32* vertexIndicesX1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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int32* vertexIndicesY1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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int32* vertexIndicesZ1 = new int32[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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//Cell bitmasks
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uint8* bitmask0 = new uint8[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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uint8* bitmask1 = new uint8[(POLYVOX_REGION_SIDE_LENGTH+1) * (POLYVOX_REGION_SIDE_LENGTH+1)];
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//When generating the mesh for a region we actually look one voxel outside it in the
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// back, bottom, right direction. Protect against access violations by cropping region here
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Region regVolume = volumeData->getEnclosingRegion();
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regVolume.setUpperCorner(regVolume.getUpperCorner() - Vector3DInt32(1,1,1));
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region.cropTo(regVolume);
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//Offset from volume corner
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const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
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//Create a region corresponding to the first slice
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Region regSlice0(region);
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regSlice0.setUpperCorner(Vector3DInt32(regSlice0.getUpperCorner().getX(),regSlice0.getUpperCorner().getY(),regSlice0.getLowerCorner().getZ()));
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//Iterator to access the volume data
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VolumeIterator<uint8> volIter(*volumeData);
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//Compute bitmask for initial slice
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uint32 uNoOfNonEmptyCellsForSlice0 = computeInitialRoughBitmaskForSlice(volIter, regSlice0, offset, bitmask0);
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if(uNoOfNonEmptyCellsForSlice0 != 0)
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{
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//If there were some non-empty cells then generate initial slice vertices for them
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generateRoughVerticesForSlice(volIter,regSlice0, offset, bitmask0, singleMaterialPatch, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0);
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}
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for(uint32 uSlice = 0; ((uSlice <= POLYVOX_REGION_SIDE_LENGTH-1) && (uSlice + offset.getZ() < region.getUpperCorner().getZ())); ++uSlice)
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{
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Region regSlice1(regSlice0);
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regSlice1.shift(Vector3DInt32(0,0,1));
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uint32 uNoOfNonEmptyCellsForSlice1 = computeRoughBitmaskForSliceFromPrevious(volIter, regSlice1, offset, bitmask1, bitmask0);
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if(uNoOfNonEmptyCellsForSlice1 != 0)
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{
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generateRoughVerticesForSlice(volIter,regSlice1, offset, bitmask1, singleMaterialPatch, vertexIndicesX1, vertexIndicesY1, vertexIndicesZ1);
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}
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if((uNoOfNonEmptyCellsForSlice0 != 0) || (uNoOfNonEmptyCellsForSlice1 != 0))
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{
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generateRoughIndicesForSlice(volIter, regSlice0, singleMaterialPatch, offset, bitmask0, bitmask1, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0, vertexIndicesX1, vertexIndicesY1, vertexIndicesZ1);
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}
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std::swap(uNoOfNonEmptyCellsForSlice0, uNoOfNonEmptyCellsForSlice1);
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std::swap(bitmask0, bitmask1);
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std::swap(vertexIndicesX0, vertexIndicesX1);
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std::swap(vertexIndicesY0, vertexIndicesY1);
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std::swap(vertexIndicesZ0, vertexIndicesZ1);
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regSlice0 = regSlice1;
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}
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delete[] bitmask0;
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delete[] bitmask1;
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delete[] vertexIndicesX0;
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delete[] vertexIndicesX1;
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delete[] vertexIndicesY0;
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delete[] vertexIndicesY1;
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delete[] vertexIndicesZ0;
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delete[] vertexIndicesZ1;
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}
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uint32 getIndex(uint32 x, uint32 y)
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{
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return x + (y * (POLYVOX_REGION_SIDE_LENGTH+1));
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}
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uint32 computeInitialRoughBitmaskForSlice(VolumeIterator<uint8>& volIter, const Region& regSlice, const Vector3DFloat& offset, uint8* bitmask)
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{
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uint32 uNoOfNonEmptyCells = 0;
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//Iterate over each cell in the region
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volIter.setPosition(regSlice.getLowerCorner().getX(),regSlice.getLowerCorner().getY(), regSlice.getLowerCorner().getZ());
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volIter.setValidRegion(regSlice);
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do
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{
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//Current position
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const uint16 x = volIter.getPosX() - offset.getX();
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const uint16 y = volIter.getPosY() - offset.getY();
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//Determine the index into the edge table which tells us which vertices are inside of the surface
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uint8 iCubeIndex = 0;
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if((x==0) && (y==0))
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{
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const uint8 v000 = volIter.getVoxel();
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const uint8 v100 = volIter.peekVoxel1px0py0pz();
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const uint8 v010 = volIter.peekVoxel0px1py0pz();
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const uint8 v110 = volIter.peekVoxel1px1py0pz();
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const uint8 v001 = volIter.peekVoxel0px0py1pz();
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const uint8 v101 = volIter.peekVoxel1px0py1pz();
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const uint8 v011 = volIter.peekVoxel0px1py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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if (v000 == 0) iCubeIndex |= 1;
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if (v100 == 0) iCubeIndex |= 2;
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if (v110 == 0) iCubeIndex |= 4;
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if (v010 == 0) iCubeIndex |= 8;
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if (v001 == 0) iCubeIndex |= 16;
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if (v101 == 0) iCubeIndex |= 32;
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if (v111 == 0) iCubeIndex |= 64;
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if (v011 == 0) iCubeIndex |= 128;
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}
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else if((x>0) && y==0)
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{
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const uint8 v100 = volIter.peekVoxel1px0py0pz();
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const uint8 v110 = volIter.peekVoxel1px1py0pz();
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const uint8 v101 = volIter.peekVoxel1px0py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//x
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uint8 iPreviousCubeIndexX = bitmask[getIndex(x-1,y)];
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uint8 srcBit6 = iPreviousCubeIndexX & 64;
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uint8 destBit7 = srcBit6 << 1;
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uint8 srcBit5 = iPreviousCubeIndexX & 32;
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uint8 destBit4 = srcBit5 >> 1;
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uint8 srcBit2 = iPreviousCubeIndexX & 4;
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uint8 destBit3 = srcBit2 << 1;
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uint8 srcBit1 = iPreviousCubeIndexX & 2;
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uint8 destBit0 = srcBit1 >> 1;
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iCubeIndex |= destBit0;
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if (v100 == 0) iCubeIndex |= 2;
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if (v110 == 0) iCubeIndex |= 4;
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iCubeIndex |= destBit3;
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iCubeIndex |= destBit4;
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if (v101 == 0) iCubeIndex |= 32;
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if (v111 == 0) iCubeIndex |= 64;
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iCubeIndex |= destBit7;
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}
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else if((x==0) && (y>0))
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{
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const uint8 v010 = volIter.peekVoxel0px1py0pz();
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const uint8 v110 = volIter.peekVoxel1px1py0pz();
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const uint8 v011 = volIter.peekVoxel0px1py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//y
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uint8 iPreviousCubeIndexY = bitmask[getIndex(x,y-1)];
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uint8 srcBit7 = iPreviousCubeIndexY & 128;
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uint8 destBit4 = srcBit7 >> 3;
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uint8 srcBit6 = iPreviousCubeIndexY & 64;
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uint8 destBit5 = srcBit6 >> 1;
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uint8 srcBit3 = iPreviousCubeIndexY & 8;
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uint8 destBit0 = srcBit3 >> 3;
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uint8 srcBit2 = iPreviousCubeIndexY & 4;
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uint8 destBit1 = srcBit2 >> 1;
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iCubeIndex |= destBit0;
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iCubeIndex |= destBit1;
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if (v110 == 0) iCubeIndex |= 4;
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if (v010 == 0) iCubeIndex |= 8;
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iCubeIndex |= destBit4;
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iCubeIndex |= destBit5;
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if (v111 == 0) iCubeIndex |= 64;
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if (v011 == 0) iCubeIndex |= 128;
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}
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else
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{
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const uint8 v110 = volIter.peekVoxel1px1py0pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//y
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uint8 iPreviousCubeIndexY = bitmask[getIndex(x,y-1)];
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uint8 srcBit7 = iPreviousCubeIndexY & 128;
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uint8 destBit4 = srcBit7 >> 3;
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uint8 srcBit6 = iPreviousCubeIndexY & 64;
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uint8 destBit5 = srcBit6 >> 1;
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uint8 srcBit3 = iPreviousCubeIndexY & 8;
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uint8 destBit0 = srcBit3 >> 3;
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uint8 srcBit2 = iPreviousCubeIndexY & 4;
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uint8 destBit1 = srcBit2 >> 1;
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//x
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uint8 iPreviousCubeIndexX = bitmask[getIndex(x-1,y)];
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srcBit6 = iPreviousCubeIndexX & 64;
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uint8 destBit7 = srcBit6 << 1;
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srcBit2 = iPreviousCubeIndexX & 4;
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uint8 destBit3 = srcBit2 << 1;
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iCubeIndex |= destBit0;
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iCubeIndex |= destBit1;
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if (v110 == 0) iCubeIndex |= 4;
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iCubeIndex |= destBit3;
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iCubeIndex |= destBit4;
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iCubeIndex |= destBit5;
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if (v111 == 0) iCubeIndex |= 64;
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iCubeIndex |= destBit7;
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}
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//Save the bitmask
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bitmask[getIndex(x,y)] = iCubeIndex;
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if(edgeTable[iCubeIndex] != 0)
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{
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++uNoOfNonEmptyCells;
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}
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}while(volIter.moveForwardInRegionXYZ());//For each cell
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return uNoOfNonEmptyCells;
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}
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uint32 computeRoughBitmaskForSliceFromPrevious(VolumeIterator<uint8>& volIter, const Region& regSlice, const Vector3DFloat& offset, uint8* bitmask, uint8* previousBitmask)
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{
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uint32 uNoOfNonEmptyCells = 0;
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//Iterate over each cell in the region
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volIter.setPosition(regSlice.getLowerCorner().getX(),regSlice.getLowerCorner().getY(), regSlice.getLowerCorner().getZ());
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volIter.setValidRegion(regSlice);
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do
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{
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//Current position
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const uint16 x = volIter.getPosX() - offset.getX();
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const uint16 y = volIter.getPosY() - offset.getY();
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//Determine the index into the edge table which tells us which vertices are inside of the surface
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uint8 iCubeIndex = 0;
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if((x==0) && (y==0))
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{
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const uint8 v001 = volIter.peekVoxel0px0py1pz();
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const uint8 v101 = volIter.peekVoxel1px0py1pz();
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const uint8 v011 = volIter.peekVoxel0px1py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//z
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uint8 iPreviousCubeIndexZ = previousBitmask[getIndex(x,y)];
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iCubeIndex = iPreviousCubeIndexZ >> 4;
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if (v001 == 0) iCubeIndex |= 16;
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if (v101 == 0) iCubeIndex |= 32;
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if (v111 == 0) iCubeIndex |= 64;
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if (v011 == 0) iCubeIndex |= 128;
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}
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else if((x>0) && y==0)
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{
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const uint8 v101 = volIter.peekVoxel1px0py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//z
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uint8 iPreviousCubeIndexZ = previousBitmask[getIndex(x,y)];
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iCubeIndex = iPreviousCubeIndexZ >> 4;
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//x
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uint8 iPreviousCubeIndexX = bitmask[getIndex(x-1,y)];
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uint8 srcBit6 = iPreviousCubeIndexX & 64;
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uint8 destBit7 = srcBit6 << 1;
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uint8 srcBit5 = iPreviousCubeIndexX & 32;
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uint8 destBit4 = srcBit5 >> 1;
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iCubeIndex |= destBit4;
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if (v101 == 0) iCubeIndex |= 32;
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if (v111 == 0) iCubeIndex |= 64;
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iCubeIndex |= destBit7;
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}
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else if((x==0) && (y>0))
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{
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const uint8 v011 = volIter.peekVoxel0px1py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//z
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uint8 iPreviousCubeIndexZ = previousBitmask[getIndex(x,y)];
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iCubeIndex = iPreviousCubeIndexZ >> 4;
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//y
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uint8 iPreviousCubeIndexY = bitmask[getIndex(x,y-1)];
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uint8 srcBit7 = iPreviousCubeIndexY & 128;
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uint8 destBit4 = srcBit7 >> 3;
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uint8 srcBit6 = iPreviousCubeIndexY & 64;
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uint8 destBit5 = srcBit6 >> 1;
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iCubeIndex |= destBit4;
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iCubeIndex |= destBit5;
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if (v111 == 0) iCubeIndex |= 64;
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if (v011 == 0) iCubeIndex |= 128;
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}
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else
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{
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//z
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uint8 iPreviousCubeIndexZ = previousBitmask[getIndex(x,y)];
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iCubeIndex = iPreviousCubeIndexZ >> 4;
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//y
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uint8 iPreviousCubeIndexY = bitmask[getIndex(x,y-1)];
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uint8 srcBit7 = iPreviousCubeIndexY & 128;
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uint8 destBit4 = srcBit7 >> 3;
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uint8 srcBit6 = iPreviousCubeIndexY & 64;
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uint8 destBit5 = srcBit6 >> 1;
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//x
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uint8 iPreviousCubeIndexX = bitmask[getIndex(x-1,y)];
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srcBit6 = iPreviousCubeIndexX & 64;
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uint8 destBit7 = srcBit6 << 1;
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iCubeIndex |= destBit4;
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iCubeIndex |= destBit5;
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if (v111 == 0) iCubeIndex |= 64;
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iCubeIndex |= destBit7;
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}
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//Save the bitmask
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bitmask[getIndex(x,y)] = iCubeIndex;
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if(edgeTable[iCubeIndex] != 0)
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{
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++uNoOfNonEmptyCells;
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}
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}while(volIter.moveForwardInRegionXYZ());//For each cell
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return uNoOfNonEmptyCells;
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}
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void generateRoughVerticesForSlice(VolumeIterator<uint8>& volIter, Region& regSlice, const Vector3DFloat& offset, uint8* bitmask, IndexedSurfacePatch* singleMaterialPatch,int32 vertexIndicesX[],int32 vertexIndicesY[],int32 vertexIndicesZ[])
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{
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//Iterate over each cell in the region
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volIter.setPosition(regSlice.getLowerCorner().getX(),regSlice.getLowerCorner().getY(), regSlice.getLowerCorner().getZ());
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volIter.setValidRegion(regSlice);
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//while(volIter.moveForwardInRegionXYZ())
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do
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{
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//Current position
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const uint16 x = volIter.getPosX() - offset.getX();
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const uint16 y = volIter.getPosY() - offset.getY();
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const uint16 z = volIter.getPosZ() - offset.getZ();
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const uint8 v000 = volIter.getVoxel();
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//Determine the index into the edge table which tells us which vertices are inside of the surface
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uint8 iCubeIndex = bitmask[getIndex(x,y)];
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/* Cube is entirely in/out of the surface */
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if (edgeTable[iCubeIndex] == 0)
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{
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continue;
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}
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/* Find the vertices where the surface intersects the cube */
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if (edgeTable[iCubeIndex] & 1)
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{
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if((x + offset.getX()) != regSlice.getUpperCorner().getX())
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{
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const uint8 v100 = volIter.peekVoxel1px0py0pz();
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const Vector3DFloat v3dPosition(x + 0.5f, y, z);
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const Vector3DFloat v3dNormal(v000 > v100 ? 1.0f : -1.0f, 0.0f, 0.0f);
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const uint8 uMaterial = v000 | v100; //Because one of these is 0, the or operation takes the max.
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const SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
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uint32 uLastVertexIndex = singleMaterialPatch->addVertex(surfaceVertex);
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vertexIndicesX[getIndex(x,y)] = uLastVertexIndex;
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}
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}
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if (edgeTable[iCubeIndex] & 8)
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{
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if((y + offset.getY()) != regSlice.getUpperCorner().getY())
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{
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const uint8 v010 = volIter.peekVoxel0px1py0pz();
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const Vector3DFloat v3dPosition(x, y + 0.5f, z);
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const Vector3DFloat v3dNormal(0.0f, v000 > v010 ? 1.0f : -1.0f, 0.0f);
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const uint8 uMaterial = v000 | v010;
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SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
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uint32 uLastVertexIndex = singleMaterialPatch->addVertex(surfaceVertex);
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vertexIndicesY[getIndex(x,y)] = uLastVertexIndex;
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}
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}
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if (edgeTable[iCubeIndex] & 256)
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{
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//if((z + offset.getZ()) != upperCorner.getZ())
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{
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const uint8 v001 = volIter.peekVoxel0px0py1pz();
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const Vector3DFloat v3dPosition(x, y, z + 0.5f);
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const Vector3DFloat v3dNormal(0.0f, 0.0f, v000 > v001 ? 1.0f : -1.0f);
|
|
const uint8 uMaterial = v000 | v001;
|
|
SurfaceVertex surfaceVertex(v3dPosition, v3dNormal, uMaterial);
|
|
uint32 uLastVertexIndex = singleMaterialPatch->addVertex(surfaceVertex);
|
|
vertexIndicesZ[getIndex(x,y)] = uLastVertexIndex;
|
|
}
|
|
}
|
|
}while(volIter.moveForwardInRegionXYZ());//For each cell
|
|
}
|
|
|
|
void generateRoughIndicesForSlice(VolumeIterator<uint8>& volIter, const Region& regSlice, IndexedSurfacePatch* singleMaterialPatch, const Vector3DFloat& offset, uint8* bitmask0, uint8* bitmask1, int32 vertexIndicesX0[],int32 vertexIndicesY0[],int32 vertexIndicesZ0[], int32 vertexIndicesX1[],int32 vertexIndicesY1[],int32 vertexIndicesZ1[])
|
|
{
|
|
uint32 indlist[12];
|
|
|
|
Region regCroppedSlice(regSlice);
|
|
regCroppedSlice.setUpperCorner(regCroppedSlice.getUpperCorner() - Vector3DInt32(1,1,0));
|
|
|
|
volIter.setPosition(regCroppedSlice.getLowerCorner().getX(),regCroppedSlice.getLowerCorner().getY(), regCroppedSlice.getLowerCorner().getZ());
|
|
volIter.setValidRegion(regCroppedSlice);
|
|
do
|
|
{
|
|
//Current position
|
|
const uint16 x = volIter.getPosX() - offset.getX();
|
|
const uint16 y = volIter.getPosY() - offset.getY();
|
|
const uint16 z = volIter.getPosZ() - offset.getZ();
|
|
|
|
//Determine the index into the edge table which tells us which vertices are inside of the surface
|
|
uint8 iCubeIndex = bitmask0[getIndex(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[getIndex(x,y)];
|
|
assert(indlist[0] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 2)
|
|
{
|
|
indlist[1] = vertexIndicesY0[getIndex(x+1,y)];
|
|
assert(indlist[1] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 4)
|
|
{
|
|
indlist[2] = vertexIndicesX0[getIndex(x,y+1)];
|
|
assert(indlist[2] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 8)
|
|
{
|
|
indlist[3] = vertexIndicesY0[getIndex(x,y)];
|
|
assert(indlist[3] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 16)
|
|
{
|
|
indlist[4] = vertexIndicesX1[getIndex(x,y)];
|
|
assert(indlist[4] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 32)
|
|
{
|
|
indlist[5] = vertexIndicesY1[getIndex(x+1,y)];
|
|
assert(indlist[5] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 64)
|
|
{
|
|
indlist[6] = vertexIndicesX1[getIndex(x,y+1)];
|
|
assert(indlist[6] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 128)
|
|
{
|
|
indlist[7] = vertexIndicesY1[getIndex(x,y)];
|
|
assert(indlist[7] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 256)
|
|
{
|
|
indlist[8] = vertexIndicesZ0[getIndex(x,y)];
|
|
assert(indlist[8] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 512)
|
|
{
|
|
indlist[9] = vertexIndicesZ0[getIndex(x+1,y)];
|
|
assert(indlist[9] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 1024)
|
|
{
|
|
indlist[10] = vertexIndicesZ0[getIndex(x+1,y+1)];
|
|
assert(indlist[10] != -1);
|
|
}
|
|
if (edgeTable[iCubeIndex] & 2048)
|
|
{
|
|
indlist[11] = vertexIndicesZ0[getIndex(x,y+1)];
|
|
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->addTriangle(ind0, ind1, ind2);
|
|
}//For each triangle
|
|
}while(volIter.moveForwardInRegionXYZ());//For each cell
|
|
}
|
|
} |