LBPM/analysis/dcel.cpp
2023-10-23 04:18:20 -04:00

470 lines
16 KiB
C++

/*
Copyright 2013--2018 James E. McClure, Virginia Polytechnic & State University
Copyright Equnior ASA
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#include "analysis/dcel.h"
DCEL::DCEL() {}
DCEL::~DCEL() {
TriangleCount = 0;
VertexCount = 0;
}
int DCEL::Face(int index) { return FaceData[index]; }
void DCEL::Write() {
int e1, e2, e3;
FILE *TRIANGLES;
TRIANGLES = fopen("triangles.stl", "w");
fprintf(TRIANGLES, "solid \n");
for (int idx = 0; idx < TriangleCount; idx++) {
e1 = Face(idx);
e2 = halfedge.next(e1);
e3 = halfedge.next(e2);
auto P1 = vertex.coords(halfedge.v1(e1));
auto P2 = vertex.coords(halfedge.v1(e2));
auto P3 = vertex.coords(halfedge.v1(e3));
fprintf(TRIANGLES, "vertex %f %f %f\n", P1.x, P1.y, P1.z);
fprintf(TRIANGLES, "vertex %f %f %f\n", P2.x, P2.y, P2.z);
fprintf(TRIANGLES, "vertex %f %f %f\n", P3.x, P3.y, P3.z);
}
fclose(TRIANGLES);
}
void DCEL::LocalIsosurface(const DoubleArray &A, double value, const int i,
const int j, const int k) {
Point P, Q;
Point PlaceHolder;
Point C0, C1, C2, C3, C4, C5, C6, C7;
Point VertexList[12];
Point NewVertexList[12];
int LocalRemap[12];
Point cellvertices[20];
std::array<std::array<int, 3>, 20> Triangles;
// Values from array 'A' at the cube corners
double CubeValues[8];
// Points corresponding to cube corners
C0.x = 0.0;
C0.y = 0.0;
C0.z = 0.0;
C1.x = 1.0;
C1.y = 0.0;
C1.z = 0.0;
C2.x = 1.0;
C2.y = 1.0;
C2.z = 0.0;
C3.x = 0.0;
C3.y = 1.0;
C3.z = 0.0;
C4.x = 0.0;
C4.y = 0.0;
C4.z = 1.0;
C5.x = 1.0;
C5.y = 0.0;
C5.z = 1.0;
C6.x = 1.0;
C6.y = 1.0;
C6.z = 1.0;
C7.x = 0.0;
C7.y = 1.0;
C7.z = 1.0;
CubeValues[0] = A(i, j, k) - value;
CubeValues[1] = A(i + 1, j, k) - value;
CubeValues[2] = A(i + 1, j + 1, k) - value;
CubeValues[3] = A(i, j + 1, k) - value;
CubeValues[4] = A(i, j, k + 1) - value;
CubeValues[5] = A(i + 1, j, k + 1) - value;
CubeValues[6] = A(i + 1, j + 1, k + 1) - value;
CubeValues[7] = A(i, j + 1, k + 1) - value;
//printf("Set cube values: %i, %i, %i \n",i,j,k);
//Determine the index into the edge table which
//tells us which vertices are inside of the surface
int CubeIndex = 0;
if (CubeValues[0] < 0.0f)
CubeIndex |= 1;
if (CubeValues[1] < 0.0f)
CubeIndex |= 2;
if (CubeValues[2] < 0.0f)
CubeIndex |= 4;
if (CubeValues[3] < 0.0f)
CubeIndex |= 8;
if (CubeValues[4] < 0.0f)
CubeIndex |= 16;
if (CubeValues[5] < 0.0f)
CubeIndex |= 32;
if (CubeValues[6] < 0.0f)
CubeIndex |= 64;
if (CubeValues[7] < 0.0f)
CubeIndex |= 128;
//Find the vertices where the surface intersects the cube
if (edgeTable[CubeIndex] & 1) {
P = VertexInterp(C0, C1, CubeValues[0], CubeValues[1]);
VertexList[0] = P;
Q = C0;
}
if (edgeTable[CubeIndex] & 2) {
P = VertexInterp(C1, C2, CubeValues[1], CubeValues[2]);
VertexList[1] = P;
Q = C1;
}
if (edgeTable[CubeIndex] & 4) {
P = VertexInterp(C2, C3, CubeValues[2], CubeValues[3]);
VertexList[2] = P;
Q = C2;
}
if (edgeTable[CubeIndex] & 8) {
P = VertexInterp(C3, C0, CubeValues[3], CubeValues[0]);
VertexList[3] = P;
Q = C3;
}
if (edgeTable[CubeIndex] & 16) {
P = VertexInterp(C4, C5, CubeValues[4], CubeValues[5]);
VertexList[4] = P;
Q = C4;
}
if (edgeTable[CubeIndex] & 32) {
P = VertexInterp(C5, C6, CubeValues[5], CubeValues[6]);
VertexList[5] = P;
Q = C5;
}
if (edgeTable[CubeIndex] & 64) {
P = VertexInterp(C6, C7, CubeValues[6], CubeValues[7]);
VertexList[6] = P;
Q = C6;
}
if (edgeTable[CubeIndex] & 128) {
P = VertexInterp(C7, C4, CubeValues[7], CubeValues[4]);
VertexList[7] = P;
Q = C7;
}
if (edgeTable[CubeIndex] & 256) {
P = VertexInterp(C0, C4, CubeValues[0], CubeValues[4]);
VertexList[8] = P;
Q = C0;
}
if (edgeTable[CubeIndex] & 512) {
P = VertexInterp(C1, C5, CubeValues[1], CubeValues[5]);
VertexList[9] = P;
Q = C1;
}
if (edgeTable[CubeIndex] & 1024) {
P = VertexInterp(C2, C6, CubeValues[2], CubeValues[6]);
VertexList[10] = P;
Q = C2;
}
if (edgeTable[CubeIndex] & 2048) {
P = VertexInterp(C3, C7, CubeValues[3], CubeValues[7]);
VertexList[11] = P;
Q = C3;
}
VertexCount = 0;
for (int idx = 0; idx < 12; idx++)
LocalRemap[idx] = -1;
for (int idx = 0; triTable[CubeIndex][idx] != -1; idx++) {
if (LocalRemap[triTable[CubeIndex][idx]] == -1) {
NewVertexList[VertexCount] = VertexList[triTable[CubeIndex][idx]];
LocalRemap[triTable[CubeIndex][idx]] = VertexCount;
VertexCount++;
}
}
//printf("Found %i vertices \n",VertexCount);
for (int idx = 0; idx < VertexCount; idx++) {
P = NewVertexList[idx];
//P.x += i;
//P.y += j;
//P.z += k;
cellvertices[idx] = P;
}
TriangleCount = 0;
for (int idx = 0; triTable[CubeIndex][idx] != -1; idx += 3) {
Triangles[TriangleCount][0] = LocalRemap[triTable[CubeIndex][idx + 0]];
Triangles[TriangleCount][1] = LocalRemap[triTable[CubeIndex][idx + 1]];
Triangles[TriangleCount][2] = LocalRemap[triTable[CubeIndex][idx + 2]];
TriangleCount++;
}
int nTris = TriangleCount;
// Now add the local values to the DCEL data structure
if (nTris > 0) {
FaceData.resize(TriangleCount);
//printf("Construct halfedge structure... \n");
//printf(" Construct %i triangles \n",nTris);
halfedge.resize(nTris * 3);
int idx_edge = 0;
for (int idx = 0; idx < TriangleCount; idx++) {
int V1 = Triangles[idx][0];
int V2 = Triangles[idx][1];
int V3 = Triangles[idx][2];
FaceData[idx] = idx_edge;
// first edge: V1->V2
halfedge.data(0, idx_edge) = V1; // first vertex
halfedge.data(1, idx_edge) = V2; // second vertex
halfedge.data(2, idx_edge) = idx; // triangle
halfedge.data(3, idx_edge) = -1; // twin
halfedge.data(4, idx_edge) = idx_edge + 2; // previous edge
halfedge.data(5, idx_edge) = idx_edge + 1; // next edge
idx_edge++;
// second edge: V2->V3
halfedge.data(0, idx_edge) = V2; // first vertex
halfedge.data(1, idx_edge) = V3; // second vertex
halfedge.data(2, idx_edge) = idx; // triangle
halfedge.data(3, idx_edge) = -1; // twin
halfedge.data(4, idx_edge) = idx_edge - 1; // previous edge
halfedge.data(5, idx_edge) = idx_edge + 1; // next edge
idx_edge++;
// third edge: V3->V1
halfedge.data(0, idx_edge) = V3; // first vertex
halfedge.data(1, idx_edge) = V1; // second vertex
halfedge.data(2, idx_edge) = idx; // triangle
halfedge.data(3, idx_edge) = -1; // twin
halfedge.data(4, idx_edge) = idx_edge - 1; // previous edge
halfedge.data(5, idx_edge) = idx_edge - 2; // next edge
idx_edge++;
//printf(" ***tri %i ***edge %i *** \n",idx, idx_edge);
}
//printf(" parsing halfedge structure\n");
int EdgeCount = idx_edge;
for (int idx = 0; idx < EdgeCount; idx++) {
int V1 = halfedge.data(0, idx);
int V2 = halfedge.data(1, idx);
// Find all the twins within the cube
for (int jdx = 0; jdx < EdgeCount; jdx++) {
if (halfedge.data(1, jdx) == V1 &&
halfedge.data(0, jdx) == V2) {
// this is the pair
halfedge.data(3, idx) = jdx;
halfedge.data(3, jdx) = idx;
}
if (halfedge.data(1, jdx) == V2 &&
halfedge.data(0, jdx) == V1 && !(idx == jdx)) {
std::printf(
"WARNING: half edges with identical orientation! \n");
}
}
// Use "ghost" twins if edge is on a cube face
P = cellvertices[V1];
Q = cellvertices[V2];
if (P.x == 0.0 && Q.x == 0.0)
halfedge.data(3, idx) = -1; // ghost twin for x=0 face
if (P.x == 1.0 && Q.x == 1.0)
halfedge.data(3, idx) = -4; // ghost twin for x=1 face
if (P.y == 0.0 && Q.y == 0.0)
halfedge.data(3, idx) = -2; // ghost twin for y=0 face
if (P.y == 1.0 && Q.y == 1.0)
halfedge.data(3, idx) = -5; // ghost twin for y=1 face
if (P.z == 0.0 && Q.z == 0.0)
halfedge.data(3, idx) = -3; // ghost twin for z=0 face
if (P.z == 1.0 && Q.z == 1.0)
halfedge.data(3, idx) = -6; // ghost twin for z=1 face
}
}
// Map vertices to global coordinates
for (int idx = 0; idx < VertexCount; idx++) {
P = cellvertices[idx];
P.x += i;
P.y += j;
P.z += k;
vertex.assign(idx, P);
}
}
Point DCEL::TriNormal(int edge) {
Point P, Q, R;
Point U, V, W;
double nx, ny, nz, len;
// at cube faces define outward normal to cube
if (edge == -1) {
W.x = -1.0;
W.y = 0.0;
W.z = 0.0; // x cube face
} else if (edge == -2) {
W.x = 0.0;
W.y = -1.0;
W.z = 0.0; // y cube face
} else if (edge == -3) {
W.x = 0.0;
W.y = 0.0;
W.z = -1.0; // z cube face
} else if (edge == -4) {
W.x = 1.0;
W.y = 0.0;
W.z = 0.0; // x cube face
} else if (edge == -5) {
W.x = 0.0;
W.y = 1.0;
W.z = 0.0; // y cube face
} else if (edge == -6) {
W.x = 0.0;
W.y = 0.0;
W.z = 1.0; // z cube face
} else {
// vertices for triange
int e2 = halfedge.next(edge);
int e3 = halfedge.next(e2);
P = vertex.coords(halfedge.v1(edge));
Q = vertex.coords(halfedge.v1(e2));
R = vertex.coords(halfedge.v1(e3));
// edge vectors
U = Q - P;
V = R - Q;
// normal vector
nx = U.y * V.z - U.z * V.y;
ny = U.z * V.x - U.x * V.z;
nz = U.x * V.y - U.y * V.x;
len = sqrt(nx * nx + ny * ny + nz * nz);
W.x = nx / len;
W.y = ny / len;
W.z = nz / len;
}
return W;
}
double DCEL::EdgeAngle(int edge) {
double angle;
double dotprod;
Point P, Q, R; // triangle vertices
Point U, V, W; // normal vectors
int e2 = halfedge.next(edge);
int e3 = halfedge.next(e2);
P = vertex.coords(halfedge.v1(edge));
Q = vertex.coords(halfedge.v1(e2));
R = vertex.coords(halfedge.v1(e3));
U = TriNormal(edge);
V = TriNormal(halfedge.twin(edge));
if (halfedge.twin(edge) < 0) {
// compute edge normal in plane of cube face
W = P - Q; // edge tangent vector
double length = sqrt(W.x * W.x + W.y * W.y + W.z * W.z);
W.x /= length;
W.y /= length;
W.z /= length;
// edge normal within the plane of the cube face
double nx = W.y * V.z - W.z * V.y;
double ny = W.z * V.x - W.x * V.z;
double nz = W.x * V.y - W.y * V.x;
length = sqrt(nx * nx + ny * ny + nz * nz);
// new value for V is this normal vector
V.x = nx / length;
V.y = ny / length;
V.z = nz / length;
dotprod = U.x * V.x + U.y * V.y + U.z * V.z;
if (dotprod < 0.f) {
//printf("negative dot product on face\n");
dotprod = -dotprod;
V.x = -V.x;
V.y = -V.y;
V.z = -V.z;
}
if (dotprod > 1.f)
dotprod = 1.f;
if (dotprod < -1.f)
dotprod = -1.f;
angle = acos(dotprod);
/* project onto plane of cube face also works
W = U - dotprod*V;
length = sqrt(W.x*W.x+W.y*W.y+W.z*W.z); // for normalization
dotprod = (U.x*W.x + U.y*W.y + U.z*W.z)/length;
if (dotprod > 1.f) dotprod=1.f;
if (dotprod < -1.f) dotprod=-1.f;
angle = acos(dotprod);
*/
} else {
dotprod = U.x * V.x + U.y * V.y + U.z * V.z;
if (dotprod > 1.f)
dotprod = 1.f;
if (dotprod < -1.f)
dotprod = -1.f;
angle = 0.5 * acos(dotprod);
}
// determine if angle is concave or convex based on edge normal
W.x = (P.y - Q.y) * U.z - (P.z - Q.z) * U.y;
W.y = (P.z - Q.z) * U.x - (P.x - Q.x) * U.z;
W.z = (P.x - Q.x) * U.y - (P.y - Q.y) * U.x;
//length = sqrt(nx*nx+ny*ny+nz*nz);
Point w = 0.5 * (P + Q) - R;
if (W.x * w.x + W.y * w.y + W.z * w.z < 0.f) {
//printf("flip edge normal \n");
W.x = -W.x;
W.y = -W.y;
W.z = -W.z;
}
if (W.x * V.x + W.y * V.y + W.z * V.z > 0.f) {
// concave
angle = -angle;
}
if (angle != angle)
angle = 0.0;
//printf("angle=%f,dot=%f (Edge=%i, twin=%i): P={%f, %f, %f}, Q={%f, %f, %f} U={%f, %f, %f}, V={%f, %f, %f}\n",angle,dotprod,edge,halfedge.twin(edge),P.x,P.y,P.z,Q.x,Q.y,Q.z,U.x,U.y,U.z,V.x,V.y,V.z);
return angle;
}
void iso_surface(const Array<double> &Field, const double isovalue) {
DCEL object;
int e1, e2, e3;
FILE *TRIANGLES;
TRIANGLES = fopen("isosurface.stl", "w");
fprintf(TRIANGLES, "solid isosurface\n");
int Nx = Field.size(0);
int Ny = Field.size(1);
int Nz = Field.size(2);
for (int k = 1; k < Nz - 1; k++) {
for (int j = 1; j < Ny - 1; j++) {
for (int i = 1; i < Nx - 1; i++) {
object.LocalIsosurface(Field, isovalue, i, j, k);
for (int idx = 0; idx < object.TriangleCount; idx++) {
e1 = object.Face(idx);
e2 = object.halfedge.next(e1);
e3 = object.halfedge.next(e2);
auto P1 = object.vertex.coords(object.halfedge.v1(e1));
auto P2 = object.vertex.coords(object.halfedge.v1(e2));
auto P3 = object.vertex.coords(object.halfedge.v1(e3));
auto Normal = object.TriNormal(e1);
// P1.x += 1.0*i; P1.y += 1.0*j; P1.z +=1.0*k;
//P2.x += 1.0*i; P2.y += 1.0*j; P2.z +=1.0*k;
//P3.x += 1.0*i; P3.y += 1.0*j; P3.z +=1.0*k;
fprintf(TRIANGLES, "facet normal %f %f %f\n", Normal.x,
Normal.y, Normal.z);
fprintf(TRIANGLES, " outer loop\n");
fprintf(TRIANGLES, " vertex %f %f %f\n", P1.x, P1.y,
P1.z);
fprintf(TRIANGLES, " vertex %f %f %f\n", P2.x, P2.y,
P2.z);
fprintf(TRIANGLES, " vertex %f %f %f\n", P3.x, P3.y,
P3.z);
fprintf(TRIANGLES, " endloop\n");
fprintf(TRIANGLES, "endfacet\n");
}
}
}
}
fprintf(TRIANGLES, "endsolid isosurface\n");
fclose(TRIANGLES);
}