Added a function to write an obj with texture coordinates & material.

Expects an isomap to exist with the filename <imagename>.isomap.png.

include/eos/render/Mesh.hpp

@@ -55,6 +55,15 @@ public:
  */
 void write_obj(Mesh mesh, std::string filename);
 
+/**
+ * Writes an obj file of the given Mesh that can be read by e.g. Meshlab.
+ * Saves texture coordinates and texture information as well.
+ *
+ * @param[in] mesh The mesh to save as obj.
+ * @param[in] filename Output filename.
+ */
+void write_textured_obj(Mesh mesh, std::string filename);
+
 	} /* namespace render */
 } /* namespace eos */
 

src/eos/render/Mesh.cpp

@@ -19,6 +19,12 @@
  */
 #include "eos/render/Mesh.hpp"
 
+#ifdef WIN32
+	#define BOOST_ALL_DYN_LINK	// Link against the dynamic boost lib. Seems to be necessary because we use /MD, i.e. link to the dynamic CRT.
+	#define BOOST_ALL_NO_LIB	// Don't use the automatic library linking by boost with VS2010 (#pragma ...). Instead, we specify everything in cmake.
+#endif
+#include "boost/filesystem/path.hpp"
+
 #include <cassert>
 #include <fstream>
 
@@ -43,5 +49,43 @@ void write_obj(Mesh mesh, std::string filename)
 	return;
 }
 
+void write_textured_obj(Mesh mesh, std::string filename)
+{
+	assert(mesh.vertices.size() == mesh.colors.size() && !mesh.texcoords.empty());
+
+	std::ofstream obj_file(filename);
+	
+	boost::filesystem::path mtl_filename(filename);
+	mtl_filename.replace_extension(".mtl");
+
+	obj_file << "mtllib " << mtl_filename.string() << std::endl; // first line of the obj file
+
+	for (std::size_t i = 0; i < mesh.vertices.size(); ++i) { //  same as in write_obj()
+		obj_file << "v " << mesh.vertices[i][0] << " " << mesh.vertices[i][1] << " " << mesh.vertices[i][2] << " " << mesh.colors[i][0] << " " << mesh.colors[i][1] << " " << mesh.colors[i][2] << " " << std::endl;
+	}
+
+	for (std::size_t i = 0; i < mesh.texcoords.size(); ++i) {
+		obj_file << "vt " << mesh.texcoords[i][0] << " " << 1.0f - mesh.texcoords[i][1] << std::endl;
+		// We invert y because Meshlab's uv origin (0, 0) is on the bottom-left
+	}
+
+	obj_file << "usemtl FaceTexture" << std::endl; // the name of our texture (material) will be 'FaceTexture'
+
+	for (auto&& v : mesh.tvi) {
+		// This assumes mesh.texcoords.size() == mesh.vertices.size(). The texture indices could theoretically be different (for example in the cube-mapped 3D scan)
+		// Add one because obj starts counting triangle indices at 1
+		obj_file << "f " << v[0] + 1 << "/" << v[0] + 1 << " " << v[1] + 1 << "/" << v[1] + 1 << " " << v[2] + 1 << "/" << v[2] + 1 << std::endl;
+	}
+
+	std::ofstream mtl_file(mtl_filename.string());
+	boost::filesystem::path texture_filename(filename);
+	texture_filename.replace_extension(".isomap.png");
+
+	mtl_file << "newmtl FaceTexture" << std::endl;
+	mtl_file << "map_Kd " << texture_filename.string() << std::endl;
+
+	return;
+}
+
 	} /* namespace render */
 } /* namespace eos */