Parse ior and transmittance of material parameter.

Add .obj sticher example.

examples/obj_sticher/obj_sticher.cc

@@ -0,0 +1,82 @@
+//
+// Stiches multiple .obj files into one .obj. 
+//
+#include "../../tiny_obj_loader.h"
+#include "obj_writer.h"
+
+#include <cassert>
+#include <iostream>
+
+typedef std::vector<tinyobj::shape_t> Shape;
+
+void
+StichObjs(
+  std::vector<tinyobj::shape_t>& out,
+  const std::vector<Shape>& shapes)
+{
+  int numShapes = 0;
+  for (size_t i = 0; i < shapes.size(); i++) {
+    numShapes += (int)shapes[i].size();
+  }
+
+  printf("Total # of shapes = %d\n", numShapes);
+
+  size_t face_offset = 0;
+  for (size_t i = 0; i < shapes.size(); i++) {
+    for (size_t k = 0; k < shapes[i].size(); k++) {
+
+      std::string new_name = shapes[i][k].name;
+      // Add suffix
+      char buf[1024];
+      sprintf(buf, "_%04d", (int)i);
+      new_name += std::string(buf);
+
+      printf("shape[%ld][%ld].name = %s\n", i, k, shapes[i][k].name.c_str());
+      assert((shapes[i][k].mesh.indices.size() % 3) == 0);
+      assert((shapes[i][k].mesh.positions.size() % 3) == 0);
+
+      tinyobj::shape_t new_shape = shapes[i][k];
+      new_shape.name = new_name;
+      printf("shape[%ld][%ld].new_name = %s\n", i, k, new_shape.name.c_str());
+
+      out.push_back(new_shape);
+    }
+  }
+}
+
+int
+main(
+  int argc,
+  char **argv)
+{
+  if (argc < 3) {
+    printf("Usage: obj_sticher input0.obj input1.obj ... output.obj\n");
+    exit(1);
+  }
+
+  int num_objfiles = argc - 2;
+  std::string out_filename = std::string(argv[argc-1]); // last element
+
+  std::vector<Shape> shapes;
+  shapes.resize(num_objfiles);
+
+  for (int i = 0; i < num_objfiles; i++) {
+    std::cout << "Loading " << argv[i+1] << " ... " << std::flush;
+    
+    std::string err = tinyobj::LoadObj(shapes[i], argv[i+1]);
+    if (!err.empty()) {
+      std::cerr << err << std::endl;
+      exit(1);
+    }
+
+    std::cout << "DONE." << std::endl;
+  }
+
+  std::vector<tinyobj::shape_t> out;
+  StichObjs(out, shapes);
+
+  bool ret = WriteObj(out_filename, out);
+  assert(ret);
+
+  return 0;
+}

examples/obj_sticher/obj_writer.cc

@@ -0,0 +1,139 @@
+//
+// Simple wavefront .obj writer
+//
+#include "obj_writer.h"
+
+static std::string GetFileBasename(const std::string& FileName)
+{
+    if(FileName.find_last_of(".") != std::string::npos)
+        return FileName.substr(0, FileName.find_last_of("."));
+    return "";
+}
+
+bool WriteMat(const std::string& filename, std::vector<tinyobj::shape_t> shapes) {
+  FILE* fp = fopen(filename.c_str(), "w");
+  if (!fp) {
+    fprintf(stderr, "Failed to open file [ %s ] for write.\n", filename.c_str());
+    return false;
+  }
+
+  std::map<std::string, tinyobj::material_t> mtl_table;
+
+  for (size_t i = 0; i < shapes.size(); i++) {
+    mtl_table[shapes[i].material.name] = shapes[i].material;
+  }
+
+  for (std::map<std::string, tinyobj::material_t>::iterator it = mtl_table.begin(); it != mtl_table.end(); it++) {
+
+    tinyobj::material_t mat = it->second;
+
+    fprintf(fp, "newmtl %s\n", mat.name.c_str());
+    fprintf(fp, "Ka %f %f %f\n", mat.ambient[0], mat.ambient[1], mat.ambient[2]);
+    fprintf(fp, "Kd %f %f %f\n", mat.diffuse[0], mat.diffuse[1], mat.diffuse[2]);
+    fprintf(fp, "Ks %f %f %f\n", mat.specular[0], mat.specular[1], mat.specular[2]);
+    fprintf(fp, "Kt %f %f %f\n", mat.transmittance[0], mat.specular[1], mat.specular[2]);
+    fprintf(fp, "Ke %f %f %f\n", mat.emission[0], mat.emission[1], mat.emission[2]);
+    fprintf(fp, "Ns %f\n", mat.shininess);
+    fprintf(fp, "Ni %f\n", mat.ior);
+    // @todo { texture }
+  }
+  
+  fclose(fp);
+
+  return true;
+}
+
+bool WriteObj(const std::string& filename, std::vector<tinyobj::shape_t> shapes) {
+  FILE* fp = fopen(filename.c_str(), "w");
+  if (!fp) {
+    fprintf(stderr, "Failed to open file [ %s ] for write.\n", filename.c_str());
+    return false;
+  }
+
+  std::string basename = GetFileBasename(filename);
+  std::string material_filename = basename + ".mtl";
+
+  int v_offset = 0;
+  int vn_offset = 0;
+  int vt_offset = 0;
+
+  fprintf(fp, "mtllib %s\n", material_filename.c_str());
+
+  for (size_t i = 0; i < shapes.size(); i++) {
+
+    bool has_vn = false;
+    bool has_vt = false;
+
+    if (shapes[i].name.empty()) {
+      fprintf(fp, "g Unknown\n");
+    } else {
+      fprintf(fp, "g %s\n", shapes[i].name.c_str());
+    }
+
+    if (!shapes[i].material.name.empty()) {
+      fprintf(fp, "usemtl %s\n", shapes[i].material.name.c_str());
+    }
+
+    // vtx
+    for (size_t k = 0; k < shapes[i].mesh.positions.size() / 3; k++) {
+      fprintf(fp, "v %f %f %f\n",
+        shapes[i].mesh.positions[3*k+0],
+        shapes[i].mesh.positions[3*k+1],
+        shapes[i].mesh.positions[3*k+2]);
+    }
+
+    // normal
+    for (size_t k = 0; k < shapes[i].mesh.normals.size() / 3; k++) {
+      fprintf(fp, "vn %f %f %f\n",
+        shapes[i].mesh.normals[3*k+0],
+        shapes[i].mesh.normals[3*k+1],
+        shapes[i].mesh.normals[3*k+2]);
+    }
+    if (shapes[i].mesh.normals.size() > 0) has_vn = true;
+
+    // texcoord
+    for (size_t k = 0; k < shapes[i].mesh.texcoords.size() / 2; k++) {
+      fprintf(fp, "vt %f %f\n",
+        shapes[i].mesh.texcoords[2*k+0],
+        shapes[i].mesh.texcoords[2*k+1]);
+    }
+    if (shapes[i].mesh.texcoords.size() > 0) has_vt = true;
+
+    // face
+    for (size_t k = 0; k < shapes[i].mesh.indices.size() / 3; k++) {
+  
+      // Face index is 1-base.
+      int v0 = shapes[i].mesh.indices[3*k+0] + 1 + v_offset;
+      int v1 = shapes[i].mesh.indices[3*k+1] + 1 + v_offset;
+      int v2 = shapes[i].mesh.indices[3*k+2] + 1 + v_offset;
+
+      if (has_vn && has_vt) {
+        fprintf(fp, "f %d/%d/%d %d/%d/%d %d/%d/%d\n",
+          v0, v0, v0, v1, v1, v1, v2, v2, v2);
+      } else if (has_vn && !has_vt) {
+        fprintf(fp, "f %d//%d %d//%d %d//%d\n", v0, v0, v1, v1, v2, v2);
+      } else if (!has_vn && has_vt) {
+        fprintf(fp, "f %d/%d %d/%d %d/%d\n", v0, v0, v1, v1, v2, v2);
+      } else {
+        fprintf(fp, "f %d %d %d\n", v0, v1, v2);
+      }
+      
+    }
+
+    v_offset  += shapes[i].mesh.positions.size() / 3;
+    vn_offset += shapes[i].mesh.normals.size() / 3;
+    vt_offset += shapes[i].mesh.texcoords.size() / 2;
+
+  }
+
+  fclose(fp);
+
+  //
+  // Write material file
+  //
+  bool ret = WriteMat(material_filename, shapes);
+
+  return ret;
+}
+
+

examples/obj_sticher/obj_writer.h

@@ -0,0 +1,9 @@
+#ifndef __OBJ_WRITER_H__
+#define __OBJ_WRITER_H__
+
+#include "../../tiny_obj_loader.h"
+
+extern bool WriteObj(const std::string& filename, std::vector<tinyobj::shape_t> shapes);
+
+
+#endif // __OBJ_WRITER_H__

examples/obj_sticher/premake4.lua

@@ -0,0 +1,38 @@
+lib_sources = {
+   "../../tiny_obj_loader.cc"
+}
+
+sources = {
+   "obj_sticher.cc",
+   "obj_writer.cc",
+   }
+
+-- premake4.lua
+solution "ObjStickerSolution"
+   configurations { "Release", "Debug" }
+
+   if (os.is("windows")) then
+      platforms { "x32", "x64" }
+   else
+      platforms { "native", "x32", "x64" }
+   end
+
+   includedirs {
+      "../../"
+   }
+
+   -- A project defines one build target
+   project "obj_sticher"
+      kind "ConsoleApp"
+      language "C++"
+      files { lib_sources, sources }
+
+      configuration "Debug"
+         defines { "DEBUG" } -- -DDEBUG
+         flags { "Symbols" }
+         targetname "obj_sticher_debug"
+
+      configuration "Release"
+         -- defines { "NDEBUG" } -- -NDEBUG
+         flags { "Symbols", "Optimize" }
+         targetname "obj_sticher"

test.cc

@@ -46,6 +46,7 @@ TestLoadObj(
     printf("  material.Tr = (%f, %f ,%f)\n", shapes[i].material.transmittance[0], shapes[i].material.transmittance[1], shapes[i].material.transmittance[2]);
     printf("  material.Ke = (%f, %f ,%f)\n", shapes[i].material.emission[0], shapes[i].material.emission[1], shapes[i].material.emission[2]);
     printf("  material.Ns = %f\n", shapes[i].material.shininess);
+    printf("  material.Ni = %f\n", shapes[i].material.ior);
     printf("  material.map_Ka = %s\n", shapes[i].material.ambient_texname.c_str());
     printf("  material.map_Kd = %s\n", shapes[i].material.diffuse_texname.c_str());
     printf("  material.map_Ks = %s\n", shapes[i].material.specular_texname.c_str());

tiny_obj_loader.cc

@@ -5,6 +5,8 @@
 //
 
 //
+// version 0.9.6: Support Ni(index of refraction) mtl parameter.
+//                Parse transmittance material parameter correctly.
 // version 0.9.5: Parse multiple group name.
 //                Add support of specifying the base path to load material file.
 // version 0.9.4: Initial suupport of group tag(g)
@@ -372,14 +374,21 @@ std::string LoadMtl (
       continue;
     }
     
-    // specular
+    // transmittance
     if (token[0] == 'K' && token[1] == 't' && isSpace((token[2]))) {
       token += 2;
       float r, g, b;
       parseFloat3(r, g, b, token);
-      material.specular[0] = r;
-      material.specular[1] = g;
-      material.specular[2] = b;
+      material.transmittance[0] = r;
+      material.transmittance[1] = g;
+      material.transmittance[2] = b;
+      continue;
+    }
+
+    // ior(index of refraction)
+    if (token[0] == 'N' && token[1] == 'i' && isSpace((token[2]))) {
+      token += 2;
+      material.ior = parseFloat(token);
       continue;
     }
 

tiny_obj_loader.h

@@ -22,6 +22,7 @@ typedef struct
     float transmittance[3];
     float emission[3];
     float shininess;
+    float ior;                // index of refraction
 
     std::string ambient_texname;
     std::string diffuse_texname;