1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
//SDFGen - A simple grid-based signed distance field (level set) generator for triangle meshes.
//Written by Christopher Batty (christopherbatty@yahoo.com, www.cs.columbia.edu/~batty)
//...primarily using code from Robert Bridson's website (www.cs.ubc.ca/~rbridson)
//This code is public domain. Feel free to mess with it, let me know if you like it.
#include "makelevelset3.h"
#include "config.h"
#ifdef HAVE_VTK
#include <vtkImageData.h>
#include <vtkFloatArray.h>
#include <vtkXMLImageDataWriter.h>
#include <vtkPointData.h>
#include <vtkSmartPointer.h>
#endif
#include <fstream>
#include <iostream>
#include <sstream>
#include <limits>
int main(int argc, char* argv[]) {
if(argc != 4) {
std::cout << "SDFGen - A utility for converting closed oriented triangle meshes into grid-based signed distance fields.\n";
std::cout << "\nThe output file format is:";
std::cout << "<ni> <nj> <nk>\n";
std::cout << "<origin_x> <origin_y> <origin_z>\n";
std::cout << "<dx>\n";
std::cout << "<value_1> <value_2> <value_3> [...]\n\n";
std::cout << "(ni,nj,nk) are the integer dimensions of the resulting distance field.\n";
std::cout << "(origin_x,origin_y,origin_z) is the 3D position of the grid origin.\n";
std::cout << "<dx> is the grid spacing.\n\n";
std::cout << "<value_n> are the signed distance data values, in ascending order of i, then j, then k.\n";
std::cout << "The output filename will match that of the input, with the OBJ suffix replaced with SDF.\n\n";
std::cout << "Usage: SDFGen <filename> <dx> <padding>\n\n";
std::cout << "Where:\n";
std::cout << "\t<filename> specifies a Wavefront OBJ (text) file representing a *triangle* mesh (no quad or poly meshes allowed). File must use the suffix \".obj\".\n";
std::cout << "\t<dx> specifies the length of grid cell in the resulting distance field.\n";
std::cout << "\t<padding> specifies the number of cells worth of padding between the object bound box and the boundary of the distance field grid. Minimum is 1.\n\n";
exit(-1);
}
std::string filename(argv[1]);
if(filename.size() < 5 || filename.substr(filename.size()-4) != std::string(".obj")) {
std::cerr << "Error: Expected OBJ file with filename of the form <name>.obj.\n";
exit(-1);
}
std::stringstream arg2(argv[2]);
float dx;
arg2 >> dx;
std::stringstream arg3(argv[3]);
int padding;
arg3 >> padding;
if(padding < 1) padding = 1;
//start with a massive inside out bound box.
Vec3f min_box(std::numeric_limits<float>::max(),std::numeric_limits<float>::max(),std::numeric_limits<float>::max()),
max_box(-std::numeric_limits<float>::max(),-std::numeric_limits<float>::max(),-std::numeric_limits<float>::max());
std::cout << "Reading data.\n";
std::ifstream infile(argv[1]);
if(!infile) {
std::cerr << "Failed to open. Terminating.\n";
exit(-1);
}
int ignored_lines = 0;
std::string line;
std::vector<Vec3f> vertList;
std::vector<Vec3ui> faceList;
while(!infile.eof()) {
std::getline(infile, line);
//.obj files sometimes contain vertex normals indicated by "vn"
if(line.substr(0,1) == std::string("v") && line.substr(0,2) != std::string("vn")){
std::stringstream data(line);
char c;
Vec3f point;
data >> c >> point[0] >> point[1] >> point[2];
vertList.push_back(point);
update_minmax(point, min_box, max_box);
}
else if(line.substr(0,1) == std::string("f")) {
std::stringstream data(line);
char c;
int v0,v1,v2;
data >> c >> v0 >> v1 >> v2;
faceList.push_back(Vec3ui(v0-1,v1-1,v2-1));
}
else if( line.substr(0,2) == std::string("vn") ){
std::cerr << "Obj-loader is not able to parse vertex normals, please strip them from the input file. \n";
exit(-2);
}
else {
++ignored_lines;
}
}
infile.close();
if(ignored_lines > 0)
std::cout << "Warning: " << ignored_lines << " lines were ignored since they did not contain faces or vertices.\n";
std::cout << "Read in " << vertList.size() << " vertices and " << faceList.size() << " faces." << std::endl;
//Add padding around the box.
Vec3f unit(1,1,1);
min_box -= padding*dx*unit;
max_box += padding*dx*unit;
Vec3ui sizes = Vec3ui((max_box - min_box)/dx);
std::cout << "Bound box size: (" << min_box << ") to (" << max_box << ") with dimensions " << sizes << "." << std::endl;
std::cout << "Computing signed distance field.\n";
Array3f phi_grid;
make_level_set3(faceList, vertList, min_box, dx, sizes[0], sizes[1], sizes[2], phi_grid);
std::string outname;
#ifdef HAVE_VTK
// If compiled with VTK, we can directly output a volumetric image format instead
//Very hackily strip off file suffix.
outname = filename.substr(0, filename.size()-4) + std::string(".vti");
std::cout << "Writing results to: " << outname << "\n";
vtkSmartPointer<vtkImageData> output_volume = vtkSmartPointer<vtkImageData>::New();
output_volume->SetDimensions(phi_grid.ni ,phi_grid.nj ,phi_grid.nk);
output_volume->SetOrigin( phi_grid.ni*dx/2, phi_grid.nj*dx/2,phi_grid.nk*dx/2);
output_volume->SetSpacing(dx,dx,dx);
vtkSmartPointer<vtkFloatArray> distance = vtkSmartPointer<vtkFloatArray>::New();
distance->SetNumberOfTuples(phi_grid.a.size());
output_volume->GetPointData()->AddArray(distance);
distance->SetName("Distance");
for(unsigned int i = 0; i < phi_grid.a.size(); ++i) {
distance->SetValue(i, phi_grid.a[i]);
}
vtkSmartPointer<vtkXMLImageDataWriter> writer =
vtkSmartPointer<vtkXMLImageDataWriter>::New();
writer->SetFileName(outname.c_str());
#if VTK_MAJOR_VERSION <= 5
writer->SetInput(output_volume);
#else
writer->SetInputData(output_volume);
#endif
writer->Write();
#else
// if VTK support is missing, default back to the original ascii file-dump.
//Very hackily strip off file suffix.
outname = filename.substr(0, filename.size()-4) + std::string(".sdf");
std::cout << "Writing results to: " << outname << "\n";
std::ofstream outfile( outname.c_str());
outfile << phi_grid.ni << " " << phi_grid.nj << " " << phi_grid.nk << std::endl;
outfile << min_box[0] << " " << min_box[1] << " " << min_box[2] << std::endl;
outfile << dx << std::endl;
for(unsigned int i = 0; i < phi_grid.a.size(); ++i) {
outfile << phi_grid.a[i] << std::endl;
}
outfile.close();
#endif
std::cout << "Processing complete.\n";
return 0;
}
|
