(mesh.numTriangles()-initialTriangles) + " triangles");
for(int iY = 0; iY < voxels.getNumSamplesY(); iY++)
for(int iZ = 0; iZ < voxels.getNumSamplesZ(); iZ++)
- march(voxels, mesh, threshold,
- iX*scaleX + voxels.getMinX(),
- iY*scaleY + voxels.getMinY(),
- iZ*scaleZ + voxels.getMinZ(),
- scaleX, scaleY, scaleZ);
+ /*marchCubes*/marchTetrahedrons(voxels, mesh, threshold,
+ iX*scaleX + voxels.getMinX(),
+ iY*scaleY + voxels.getMinY(),
+ iZ*scaleZ + voxels.getMinZ(),
+ scaleX, scaleY, scaleZ);
}
System.out.print("\r");
for(int i=0; i<78; i++) System.out.print(' ');
}
/** performs the Marching Cubes algorithm on a single cube */
- static void march(VoxelData voxels, Mesh mesh, double threshold,
- double fX, double fY, double fZ,
- double scaleX, double scaleY, double scaleZ) {
+ static void marchCubes(VoxelData voxels, Mesh mesh, double threshold,
+ double fX, double fY, double fZ,
+ double scaleX, double scaleY, double scaleZ) {
int iCorner, iVertex, iVertexTest, iEdge, iTriangle, iFlagIndex, iEdgeFlags;
double fOffset;
GLvector sColor;
vGetNormal(voxels, asEdgeNorm[iEdge], asEdgeVertex[iEdge].fX, asEdgeVertex[iEdge].fY, asEdgeVertex[iEdge].fZ);
}
+ System.out.println();
+
// Draw the triangles that were found. There can be up to five per cube
for(iTriangle = 0; iTriangle < 5; iTriangle++) {
if(a2iTriangleConnectionTable[iFlagIndex][3*iTriangle] < 0)
points[1].equals(points[2]))
continue;
- mesh.newT(points[0], points[1], points[2], norm.norm().times(-1));
+ System.out.println("creating triangle: " + points[0] + " " + points[1] + " " + points[2]);
+ try {
+ Mesh.T t = mesh.newT(points[0], points[1], points[2], norm.norm().times(-1));
+ System.out.println(" created " + t);
+ } catch (Throwable t) { }
+ }
+ }
+
+ /**
+ * marchTetrahedron performs the Marching Tetrahedrons algorithm
+ * on a single tetrahedron
+ */
+ static void marchTetrahedron(VoxelData voxels, Mesh mesh, double threshold,
+ GLvector[] pasTetrahedronPosition,
+ float[] pafTetrahedronValue,
+ double scaleX, double scaleY, double scaleZ) {
+
+ int iEdge, iVert0, iVert1, iEdgeFlags, iTriangle, iCorner, iVertex, iFlagIndex = 0;
+ double fOffset, fInvOffset, fValue = 0.0;
+ GLvector[] asEdgeVertex = new GLvector[6];
+ GLvector[] asEdgeNorm = new GLvector[6];
+ GLvector sColor = new GLvector();
+ for(int i=0; i<asEdgeVertex.length; i++) asEdgeVertex[i] = new GLvector();
+ for(int i=0; i<asEdgeNorm.length; i++) asEdgeNorm[i] = new GLvector();
+
+ // Find which vertices are inside of the surface and which are outside
+ for(iVertex = 0; iVertex < 4; iVertex++)
+ if(pafTetrahedronValue[iVertex] <= threshold)
+ iFlagIndex |= 1<<iVertex;
+
+ // Find which edges are intersected by the surface
+ iEdgeFlags = aiTetrahedronEdgeFlags[iFlagIndex];
+
+ // If the tetrahedron is entirely inside or outside of the surface, then there will be no intersections
+ if(iEdgeFlags == 0) return;
+
+ // Find the point of intersection of the surface with each edge
+ // Then find the normal to the surface at those points
+ for(iEdge = 0; iEdge < 6; iEdge++) {
+ // if there is an intersection on this edge
+ if( (iEdgeFlags & (1<<iEdge))==0 ) continue;
+
+ iVert0 = a2iTetrahedronEdgeConnection[iEdge][0];
+ iVert1 = a2iTetrahedronEdgeConnection[iEdge][1];
+ fOffset = fGetOffset(pafTetrahedronValue[iVert0], pafTetrahedronValue[iVert1], threshold,
+ Math.min(Math.min(scaleX, scaleY), scaleZ) * 0.1);
+ fInvOffset = 1.0f - fOffset;
+
+ asEdgeVertex[iEdge].fX = fInvOffset*pasTetrahedronPosition[iVert0].fX + fOffset*pasTetrahedronPosition[iVert1].fX;
+ asEdgeVertex[iEdge].fY = fInvOffset*pasTetrahedronPosition[iVert0].fY + fOffset*pasTetrahedronPosition[iVert1].fY;
+ asEdgeVertex[iEdge].fZ = fInvOffset*pasTetrahedronPosition[iVert0].fZ + fOffset*pasTetrahedronPosition[iVert1].fZ;
+
+ vGetNormal(voxels, asEdgeNorm[iEdge], asEdgeVertex[iEdge].fX, asEdgeVertex[iEdge].fY, asEdgeVertex[iEdge].fZ);
+ }
+
+ // Draw the triangles that were found. There can be up to 2 per tetrahedron
+ for(iTriangle = 0; iTriangle < 2; iTriangle++) {
+ if(a2iTetrahedronTriangles[iFlagIndex][3*iTriangle] < 0) break;
+
+ Point[] points = new Point[3];
+ Vec norm = new Vec(0,0,0);
+ for(iCorner = 0; iCorner < 3; iCorner++) {
+ iVertex = a2iTetrahedronTriangles[iFlagIndex][3*iTriangle+iCorner];
+ points[iCorner] = new Point(asEdgeVertex[iVertex].fX, asEdgeVertex[iVertex].fY, asEdgeVertex[iVertex].fZ);
+ // questionable, but we do it anyways
+ norm = norm.plus(new Vec(asEdgeNorm[iVertex].fX, asEdgeNorm[iVertex].fY, asEdgeNorm[iVertex].fZ));
+ }
+ // Eliminate triangles with "length-zero" sides.
+ // Unfortunately this puts holes in the mesh.
+ if (points[0].equals(points[1]) ||
+ points[0].equals(points[2]) ||
+ points[1].equals(points[2]))
+ continue;
+ System.out.println("creating triangle: " + points[0] + " " + points[1] + " " + points[2]);
+ Mesh.T t = mesh.newT(points[0], points[1], points[2], norm.norm().times(-1));
+ System.out.println(" created " + t);
+ }
+ }
+
+ /**
+ * marchTetrahedrons performs the Marching Tetrahedrons algorithm on a
+ * single cube by making six calls to marchTetrahedron
+ */
+ static void marchTetrahedrons(VoxelData voxels, Mesh mesh, double threshold,
+ double fX, double fY, double fZ,
+ double scaleX, double scaleY, double scaleZ) {
+ int iVertex, iTetrahedron, iVertexInACube;
+ GLvector[] asCubePosition = new GLvector[8];
+ float[] afCubeValue = new float[8];
+ GLvector[] asTetrahedronPosition = new GLvector[8];
+ float[] afTetrahedronValue = new float[4];
+
+ for(int i=0; i<asCubePosition.length; i++) asCubePosition[i] = new GLvector();
+ for(int i=0; i<asTetrahedronPosition.length; i++) asTetrahedronPosition[i] = new GLvector();
+
+ // Make a local copy of the cube's corner positions
+ for(iVertex = 0; iVertex < 8; iVertex++) {
+ asCubePosition[iVertex].fX = fX + a2fVertexOffset[iVertex][0]*scaleX;
+ asCubePosition[iVertex].fY = fY + a2fVertexOffset[iVertex][1]*scaleY;
+ asCubePosition[iVertex].fZ = fZ + a2fVertexOffset[iVertex][2]*scaleZ;
+ }
+
+ // Make a local copy of the cube's corner values
+ for(iVertex = 0; iVertex < 8; iVertex++)
+ afCubeValue[iVertex] =
+ voxels.getSample(new Point(asCubePosition[iVertex].fX,
+ asCubePosition[iVertex].fY,
+ asCubePosition[iVertex].fZ));
+
+ for(iTetrahedron = 0; iTetrahedron < 6; iTetrahedron++) {
+ for(iVertex = 0; iVertex < 4; iVertex++) {
+ iVertexInACube = a2iTetrahedronsInACube[iTetrahedron][iVertex];
+ asTetrahedronPosition[iVertex].fX = asCubePosition[iVertexInACube].fX;
+ asTetrahedronPosition[iVertex].fY = asCubePosition[iVertexInACube].fY;
+ asTetrahedronPosition[iVertex].fZ = asCubePosition[iVertexInACube].fZ;
+ afTetrahedronValue[iVertex] = afCubeValue[iVertexInACube];
+ }
+ marchTetrahedron(voxels, mesh, threshold, asTetrahedronPosition, afTetrahedronValue, scaleX, scaleY, scaleZ);
}
}
projects / anneal.git / commitdiff