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Fix: Enhance OBJ parser to support variable face formats (v//vn, v/vt) #163

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Fix: Enhance OBJ parser to support variable face formats (v//vn, v/vt) #163

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71 changes: 38 additions & 33 deletions model.cpp
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
#include "model.h"
#include <fstream>
#include <sstream>
#include "model.h"

Model::Model(const std::string filename) {
std::ifstream in;
Expand All @@ -13,70 +13,75 @@ Model::Model(const std::string filename) {
char trash;
if (!line.compare(0, 2, "v ")) {
iss >> trash;
vec4 v = {0,0,0,1};
for (int i : {0,1,2}) iss >> v[i];
vec4 v = { 0, 0, 0, 1 };
for (int i : { 0, 1, 2 }) iss >> v[i];
verts.push_back(v);
} else if (!line.compare(0, 3, "vn ")) {
iss >> trash >> trash;
vec4 n;
for (int i : {0,1,2}) iss >> n[i];
for (int i : { 0, 1, 2 }) iss >> n[i];
norms.push_back(normalized(n));
} else if (!line.compare(0, 3, "vt ")) {
iss >> trash >> trash;
vec2 uv;
for (int i : {0,1}) iss >> uv[i];
tex.push_back({uv.x, 1-uv.y});
for (int i : { 0, 1 }) iss >> uv[i];
tex.push_back({ uv.x, 1 - uv.y });
} else if (!line.compare(0, 2, "f ")) {
int f,t,n, cnt = 0;
iss >> trash;
while (iss >> f >> trash >> t >> trash >> n) {
std::string token;
int f, t, n;
int cnt = 0;

while (iss >> token) {
f = 1;
t = 1;
n = 1;

if (sscanf(token.c_str(), "%d/%d/%d", &f, &t, &n) == 3) {
} else if (sscanf(token.c_str(), "%d//%d", &f, &n) == 2) {
} else if (sscanf(token.c_str(), "%d/%d", &f, &t) == 2) {
} else {
sscanf(token.c_str(), "%d", &f);
}
facet_vrt.push_back(--f);
facet_tex.push_back(--t);
facet_nrm.push_back(--n);
cnt++;
}
if (3!=cnt) {
if (3 != cnt) {
std::cerr << "Error: the obj file is supposed to be triangulated" << std::endl;
return;
}
}
}
std::cerr << "# v# " << nverts() << " f# " << nfaces() << std::endl;
std::cerr << "# v# " << nverts() << " f# " << nfaces() << std::endl;
auto load_texture = [&filename](const std::string suffix, TGAImage &img) {
size_t dot = filename.find_last_of(".");
if (dot==std::string::npos) return;
std::string texfile = filename.substr(0,dot) + suffix;
std::cerr << "texture file " << texfile << " loading " << (img.read_tga_file(texfile.c_str()) ? "ok" : "failed") << std::endl;
if (dot == std::string::npos) return;
std::string texfile = filename.substr(0, dot) + suffix;
std::cerr << "texture file " << texfile << " loading " << (img.read_tga_file(texfile.c_str()) ? "ok" : "failed")
<< std::endl;
};
load_texture("_diffuse.tga", diffusemap );
load_texture("_diffuse.tga", diffusemap);
load_texture("_nm_tangent.tga", normalmap);
load_texture("_spec.tga", specularmap);
load_texture("_spec.tga", specularmap);
}

int Model::nverts() const { return verts.size(); }
int Model::nfaces() const { return facet_vrt.size()/3; }
int Model::nfaces() const { return facet_vrt.size() / 3; }

vec4 Model::vert(const int i) const {
return verts[i];
}
vec4 Model::vert(const int i) const { return verts[i]; }

vec4 Model::vert(const int iface, const int nthvert) const {
return verts[facet_vrt[iface*3+nthvert]];
}
vec4 Model::vert(const int iface, const int nthvert) const { return verts[facet_vrt[iface * 3 + nthvert]]; }

vec4 Model::normal(const int iface, const int nthvert) const {
return norms[facet_nrm[iface*3+nthvert]];
}
vec4 Model::normal(const int iface, const int nthvert) const { return norms[facet_nrm[iface * 3 + nthvert]]; }

vec4 Model::normal(const vec2 &uv) const {
TGAColor c = normalmap.get(uv[0]*normalmap.width(), uv[1]*normalmap.height());
return normalized(vec4{(double)c[2],(double)c[1],(double)c[0],0}*2./255. - vec4{1,1,1,0});
}

vec2 Model::uv(const int iface, const int nthvert) const {
return tex[facet_tex[iface*3+nthvert]];
TGAColor c = normalmap.get(uv[0] * normalmap.width(), uv[1] * normalmap.height());
return normalized(vec4 { (double)c[2], (double)c[1], (double)c[0], 0 } * 2. / 255. - vec4 { 1, 1, 1, 0 });
}

const TGAImage& Model::diffuse() const { return diffusemap; }
const TGAImage& Model::specular() const { return specularmap; }
vec2 Model::uv(const int iface, const int nthvert) const { return tex[facet_tex[iface * 3 + nthvert]]; }

const TGAImage &Model::diffuse() const { return diffusemap; }
const TGAImage &Model::specular() const { return specularmap; }