用於製作在OpenGL

-1

一個加載OBJ模型

我已加載使用這個對象（.OBJ）模型（從這個tutorial）着色器：用於製作在OpenGL

void Model::loadOBJ(const char * path, std::vector <vector3> & out_vertices, std::vector <vector2> & out_uvs, std::vector <vector3> & out_normals){ 
std::vector<unsigned int> vertexIndices, uvIndices, normalIndices; 
std::vector<vector3> temp_vertices; 
std::vector<vector2> temp_uvs; 
std::vector<vector3> temp_normals; 

FILE * file = fopen(path, "r"); 
if (file == NULL) 
    return; 
while (1){ 
    char lineHeader[128]; 
    int res = fscanf(file, "%s", lineHeader); 
    if (res == EOF) 
     break; 
    if (strcmp(lineHeader, "v") == 0){ 
     vector3 vertex; 
     fscanf(file, "%f %f %f\n", &vertex.x, &vertex.y, &vertex.z); 
     temp_vertices.push_back(vertex); 
    }else if (strcmp(lineHeader, "vt") == 0){ 
     vector2 uv; 
     fscanf(file, "%f %f\n", &uv.x, &uv.y); 
     temp_uvs.push_back(uv); 
    }else if (strcmp(lineHeader, "f") == 0){ 
     std::string vertex1, vertex2, vertex3; 
     unsigned int vertexIndex[3], uvIndex[3], normalIndex[3]; 
     int matches = fscanf(file, "%d/%d/%d %d/%d/%d %d/%d/%d\n", &vertexIndex[0], &uvIndex[0], &normalIndex[0], &vertexIndex[1], &uvIndex[1], &normalIndex[1], &vertexIndex[2], &uvIndex[2], &normalIndex[2]); 
     if (matches != 9){ 
      exit(matches); 
      return;} 
     vertexIndices.push_back(vertexIndex[0]); 
     vertexIndices.push_back(vertexIndex[1]); 
     vertexIndices.push_back(vertexIndex[2]); 
     uvIndices.push_back(uvIndex[0]); 
     uvIndices.push_back(uvIndex[1]); 
     uvIndices.push_back(uvIndex[2]); 
     normalIndices.push_back(normalIndex[0]); 
     normalIndices.push_back(normalIndex[1]); 
     normalIndices.push_back(normalIndex[2]); 
    } 
} 
for (unsigned int i = 0; i < vertexIndices.size(); i++){ 
    unsigned int vertexIndex = vertexIndices[i]; 
    vector3 vertex = temp_vertices[vertexIndex - 1]; 
    out_vertices.push_back(vertex); 
} 
for (unsigned int i = 0; i < uvIndices.size(); i++){ 
    unsigned int uvIndex = uvIndices[i]; 
    vector2 uv = temp_uvs[uvIndex - 1]; 
    //vertex.normalise(); 
    out_uvs.push_back(uv); 
} 
}

和我一起繪製

void Model::draw() 
{ 
glEnable(GL_TEXTURE_2D); 
glBindTexture(GL_TEXTURE_2D, texture); 
glBegin(GL_TRIANGLES); 
glPushMatrix(); 
glLoadIdentity(); 
glClearColor(0.0, 0.0, 0.0, 0.0); 
glColor3f(1, 1, 1); 
for (int l_index = 0; l_index < vertices.size(); l_index++) 
{ 
    glTexCoord2f(uvs[l_index].x, uvs[l_index].y); 
    glVertex3f(vertices[l_index].x * 5, vertices[l_index].y * 5, vertices[l_index].z * 5); 
} 
glDisable(GL_TEXTURE_2D); 
glEnd(); 
}

該模型正確加載並保存.obj文件中的法線，uvs和頂點。

我該如何着手製作這個着色器？

來源

2014-10-02 bbdude95

您將需要閱讀關於GLSL基礎知識的一些教程。由於您的模型包含xyz位置，uv紋理座標和xyz法線，因此這些將是您對頂點着色器的輸入。頂點着色器將使用你的世界/視圖/投影矩陣將頂點轉換爲剪輯空間，將紋理座標傳遞給像素着色器，像素着色器將從紋理貼圖中查找顏色。

來源

2014-10-02 01:49:18 megadan

用於製作在OpenGL

回答

相關問題