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Merge pull request #79 from Vazquinhos/master

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Flat normals calculation of obj without normals
This commit is contained in:
Syoyo Fujita
2016-05-13 19:46:47 +09:00
parent 9c81fcb4cc 9aee576b99
commit 1ab0d147cb
2 changed files with 116 additions and 15 deletions
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7
test.cc
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@@ -124,7 +124,7 @@ static bool
TestLoadObj(
const char* filename,
const char* basepath = NULL,
bool triangulate = true)
unsigned int flags = 1 )
{
std::cout << "Loading " << filename << std::endl;
@@ -132,7 +132,7 @@ TestLoadObj(
std::vector<tinyobj::material_t> materials;
std::string err;
bool ret = tinyobj::LoadObj(shapes, materials, err, filename, basepath, triangulate);
bool ret = tinyobj::LoadObj(shapes, materials, err, filename, basepath, flags);
if (!err.empty()) {
std::cerr << err << std::endl;
@@ -143,7 +143,8 @@ TestLoadObj(
return false;
}
PrintInfo(shapes, materials, triangulate);
bool triangulate( ( flags & tinyobj::triangulation ) == tinyobj::triangulation );
PrintInfo(shapes, materials, triangulate );
return true;
}

124
tiny_obj_loader.h
View File

@@ -44,6 +44,7 @@
#include <string>
#include <vector>
#include <map>
#include <cmath>
namespace tinyobj {
@@ -97,6 +98,69 @@ typedef struct {
mesh_t mesh;
} shape_t;
typedef enum
{
triangulation = 1, // used whether triangulate polygon face in .obj
calculate_normals = 2, // used whether calculate the normals if the .obj normals are empty
// Some nice stuff here
} load_flags_t;
class float3
{
public:
float3()
: x( 0.0f )
, y( 0.0f )
, z( 0.0f )
{
}
float3(float coord_x, float coord_y, float coord_z)
: x( coord_x )
, y( coord_y )
, z( coord_z )
{
}
float3(const float3& from, const float3& to)
{
coord[0] = to.coord[0] - from.coord[0];
coord[1] = to.coord[1] - from.coord[1];
coord[2] = to.coord[2] - from.coord[2];
}
float3 crossproduct ( const float3 & vec )
{
float a = y * vec.z - z * vec.y ;
float b = z * vec.x - x * vec.z ;
float c = x * vec.y - y * vec.x ;
return float3( a , b , c );
}
void normalize()
{
const float length = std::sqrt( ( coord[0] * coord[0] ) +
( coord[1] * coord[1] ) +
( coord[2] * coord[2] ) );
if( length != 1 )
{
coord[0] = (coord[0] / length);
coord[1] = (coord[1] / length);
coord[2] = (coord[2] / length);
}
}
private:
union
{
float coord[3];
struct
{
float x,y,z;
};
};
};
class MaterialReader {
public:
MaterialReader() {}
@@ -127,13 +191,12 @@ private:
/// Returns true when loading .obj become success.
/// Returns warning and error message into `err`
/// 'mtl_basepath' is optional, and used for base path for .mtl file.
/// 'triangulate' is optional, and used whether triangulate polygon face in .obj
/// or not.
/// 'optional flags
bool LoadObj(std::vector<shape_t> &shapes, // [output]
std::vector<material_t> &materials, // [output]
std::string &err, // [output]
const char *filename, const char *mtl_basepath = NULL,
bool triangulate = true);
unsigned int flags = 1 );
/// Loads object from a std::istream, uses GetMtlIStreamFn to retrieve
/// std::istream for materials.
@@ -143,7 +206,7 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
std::vector<material_t> &materials, // [output]
std::string &err, // [output]
std::istream &inStream, MaterialReader &readMatFn,
bool triangulate = true);
unsigned int flags = 1);
/// Loads materials into std::map
void LoadMtl(std::map<std::string, int> &material_map, // [output]
@@ -516,11 +579,14 @@ static bool exportFaceGroupToShape(
const std::vector<float> &in_texcoords,
const std::vector<std::vector<vertex_index> > &faceGroup,
std::vector<tag_t> &tags, const int material_id, const std::string &name,
bool clearCache, bool triangulate) {
bool clearCache, unsigned int flags, std::string& err ) {
if (faceGroup.empty()) {
return false;
}
bool triangulate( ( flags & triangulation ) == triangulation );
bool normals_calculation( ( flags & calculate_normals ) == calculate_normals );
// Flatten vertices and indices
for (size_t i = 0; i < faceGroup.size(); i++) {
const std::vector<vertex_index> &face = faceGroup[i];
@@ -569,6 +635,38 @@ static bool exportFaceGroupToShape(
shape.mesh.num_vertices.push_back(static_cast<unsigned char>(npolys));
shape.mesh.material_ids.push_back(material_id); // per face
}
if( normals_calculation && shape.mesh.normals.empty() )
{
const unsigned int nIndexs = shape.mesh.indices.size();
shape.mesh.normals.resize(shape.mesh.positions.size());
if( nIndexs % 3 == 0 )
{
for ( register unsigned int iIndices = 0; iIndices < nIndexs; iIndices+=3 )
{
float3 v1, v2, v3;
memcpy(&v1, &shape.mesh.positions[shape.mesh.indices[iIndices] * 3], sizeof(float3));
memcpy(&v2, &shape.mesh.positions[shape.mesh.indices[iIndices + 1] * 3], sizeof(float3));
memcpy(&v3, &shape.mesh.positions[shape.mesh.indices[iIndices + 2] * 3], sizeof(float3));
float3 v12( v1,v2 );
float3 v13( v1,v3 );
float3 normal = v12.crossproduct(v13);
normal.normalize();
memcpy(&shape.mesh.normals[shape.mesh.indices[iIndices] * 3], &normal, sizeof(float3));
memcpy(&shape.mesh.normals[shape.mesh.indices[iIndices + 1] * 3], &normal, sizeof(float3));
memcpy(&shape.mesh.normals[shape.mesh.indices[iIndices + 2] * 3], &normal, sizeof(float3));
}
}
else
{
std::stringstream ss;
ss << "WARN: The shape " << name << " does not have a topology of triangles, therfore the normals calculation could not be performed. Select the tinyobj::triangulation flag for this object." << std::endl;
err += ss.str();
}
}
}
shape.name = name;
@@ -834,7 +932,7 @@ bool MaterialFileReader::operator()(const std::string &matId,
bool LoadObj(std::vector<shape_t> &shapes, // [output]
std::vector<material_t> &materials, // [output]
std::string &err, const char *filename, const char *mtl_basepath,
bool trianglulate) {
unsigned int flags) {
shapes.clear();
@@ -853,13 +951,14 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
}
MaterialFileReader matFileReader(basePath);
return LoadObj(shapes, materials, err, ifs, matFileReader, trianglulate);
return LoadObj(shapes, materials, err, ifs, matFileReader, flags);
}
bool LoadObj(std::vector<shape_t> &shapes, // [output]
std::vector<material_t> &materials, // [output]
std::string &err, std::istream &inStream,
MaterialReader &readMatFn, bool triangulate) {
MaterialReader &readMatFn, unsigned int flags) {
std::stringstream errss;
std::vector<float> v;
@@ -986,7 +1085,7 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
if (newMaterialId != material) {
// Create per-face material
exportFaceGroupToShape(shape, vertexCache, v, vn, vt, faceGroup, tags,
material, name, true, triangulate);
material, name, true, flags, err );
faceGroup.clear();
material = newMaterialId;
}
@@ -1022,7 +1121,7 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
// flush previous face group.
bool ret =
exportFaceGroupToShape(shape, vertexCache, v, vn, vt, faceGroup, tags,
material, name, true, triangulate);
material, name, true, flags, err );
if (ret) {
shapes.push_back(shape);
}
@@ -1059,7 +1158,7 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
// flush previous face group.
bool ret =
exportFaceGroupToShape(shape, vertexCache, v, vn, vt, faceGroup, tags,
material, name, true, triangulate);
material, name, true, flags, err );
if (ret) {
shapes.push_back(shape);
}
@@ -1130,13 +1229,14 @@ bool LoadObj(std::vector<shape_t> &shapes, // [output]
}
bool ret = exportFaceGroupToShape(shape, vertexCache, v, vn, vt, faceGroup,
tags, material, name, true, triangulate);
tags, material, name, true, flags, err );
if (ret) {
shapes.push_back(shape);
}
faceGroup.clear(); // for safety
err += errss.str();
return true;
}