model2pbrt.cpp

#include <assimp/Importer.hpp>      // C++ importer interface
#include <assimp/scene.h>           // Output data structure
#include <assimp/postprocess.h>     // Post processing flags

#include <iostream>
#include <string>
#include <fstream>
#include <vector>
using namespace std;

class MaterialInfo
{
public:
	string name;
};

std::ostream &operator<<(std::ostream &os, aiColor3D const &col)
{ 
	return os << col[0] << " " << col[1] << " " << col[2];
}


int main(int argc, char** argv)
{
	if(argc != 3)
	{
		cout << "Usage : model2pbrt <inputModel> <output>" << endl;
		return 0;
	}

	const string outFileName = argv[2];
	const string inFileName = argv[1];
	fstream file;
	file.open(outFileName, ios::out);
	
	if(!file)
	{
		cout << "Error : Cannot open/create file " << outFileName << endl;
		return 1;
	}
	
	Assimp::Importer importer;
	const aiScene* scene = importer.ReadFile( inFileName.c_str(),
		aiProcess_CalcTangentSpace       |
		aiProcess_Triangulate            |
		aiProcess_JoinIdenticalVertices  |
		aiProcess_SortByPType		 |
	 	aiProcess_GenSmoothNormals);
	if(scene == NULL)
	{
		cout << "Faild to load model " << inFileName << "." << endl;
		return 0;
	}
	
	//Output material data
	vector<MaterialInfo> materials;
	for(int i=0 ;i<scene->mNumMaterials;i++)
	{
		const aiMaterial* material = scene->mMaterials[i];
		aiString name;
		aiString texturePath;
		string textureName;
		bool textured = false;
		
		if(material->Get(AI_MATKEY_NAME, name) != AI_SUCCESS)
		{
			cout << "Error : Material must be named" << endl;
			return 0;
		}
		
		if(material->GetTextureCount(aiTextureType_DIFFUSE) > 0)
		{
			if(material->GetTexture(aiTextureType_DIFFUSE, 0
				, &texturePath, NULL, NULL, NULL, NULL, NULL)
				== AI_SUCCESS)
			{
				textured = true;
				textureName = string(name.C_Str())+string("_texture_Kd");
				file << "Texture \"" << textureName << "\" "
					<< "\"color\" \"imagemap\" \"string filename\" "
					<< "\"" << texturePath.C_Str() << "\"" << endl;
			}
		}

		aiColor3D diffuseColor(1,1,1);
		material->Get(AI_MATKEY_COLOR_DIFFUSE, diffuseColor);
		
		file << "MakeNamedMaterial " << "\"" << name.C_Str() << "\" ";
		
		file << "\"string type\" \"matte\" "
			<< "\"rgb Kd\" [" << diffuseColor << "] ";
		
		if(textured)
			file << "\"texture Kd\" " << "\"" << textureName << "\"";
		
		
		MaterialInfo materialInfo;
		materialInfo.name = name.C_Str();
		materials.push_back(materialInfo);
		
		file << endl;
	}
	
	//Output the mesh data
	int meshCount = scene->mNumMeshes;
	for(int i=0;i<meshCount;i++)
	{
		aiMesh* mesh = scene->mMeshes[i];
		int meshFaces = mesh->mNumFaces;
		int verticesNum = mesh->mNumVertices;
		int materialIndex = mesh->mMaterialIndex;
		
		file << "NamedMaterial \"" << materials[materialIndex].name << "\"" << endl;

		file << "Shape \"trianglemesh\" " << endl;
		file << "\t\"point P\" " << "[";
		for(int j=0;j<verticesNum;j++)
		{
			for(int k=0;k<3;k++)
				file << mesh->mVertices[j][k] << " ";

		}
		file << "]" << endl;


		file << "\t\"integer indices\" " << "[";
		for(int j=0;j<meshFaces;j++)
		{
			for(int k=0;k<3;k++)
				file << mesh->mFaces[j].mIndices[k] << " ";
		}
		file << "]" << endl;

		if(mesh->HasNormals() == true)
		{
			file << "\t\"normal N\" " << "[";
			for(int j=0;j<verticesNum;j++)
			{
				for(int k=0;k<3;k++)
					file << mesh->mNormals[j][k] << " ";
			}
			file << "]" << endl;
		}

		if(mesh->HasTextureCoords(0))
		{
			file << "\t\"float uv\" " << "[";
			for(int j=0;j<verticesNum;j++)
			{
				for(int k=0;k<2;k++)
					file << mesh->mTextureCoords[0][j][k] << " ";
			}
			file << "]" << endl;
		}

	}
	file.close();
	return 0;
}