Visual studio OBJ文件加载器未正确读取面

我创建了一个用于OpenGL的小OBJ文件加载器，但根本不读取面。在添加face reader之前，程序可以读取所有内容，所以我在这里有点困惑。这是我的密码：

void OBJLoader::LoadObjFile(std::string f,std::vector<float>& v,std::vector<float>& n,std::vector<float>& u)
{
std::ifstream file;
file.open(f);

OutputDebugStringA("OPENING FILE-\n");
OutputDebugStringA(f.c_str());
std::string vertex,normal,uv,face;

std::string data;
std::string data2;
std::string data3 = "";

uv = "vt";
normal = "vn";
vertex = "v";
face = "f";

std::size_t var1;
int i = 1;
int j = 1;
int k = 1;
bool loop = true;
int loopcount = 1;

std::vector<float> tV,tU,tN;

if(file.is_open())
{
    while(std::getline(file,data) && file.good())
    {

        var1 = data.find(vertex);
        if(var1 != std::string::npos && var1 < data.size() && data[1] == 0x20)
        {
            data3.append(data,2,std::string::npos);

            double v1,v2,v3;
            std::istringstream ss(data3);
            if(ss >> v1 >> v2 >> v3){ v.push_back((float)v1); v.push_back((float)v2); v.push_back((float)v3); i++;}
            else
            {
                OutputDebugStringA("Error reading vertex data.\n");
                std::stringstream ssc;
                ssc << loopcount;
                std::string str = ssc.str();
                OutputDebugStringA((char*)str.c_str());
                OutputDebugStringA("\n");

            }
            data3 = "";
            data2 = "";
        }

        var1 = data.find(normal);
        if(var1 != std::string::npos && var1 < data.size())
        {
            data3.append(data,3,std::string::npos);

            float v1,v2,v3;
            std::istringstream ss(data3);
            if(ss >> v1 >> v2 >> v3){ n.push_back((float)v1); n.push_back((float)v2); n.push_back((float)v3); j++;}
            else
            {
                OutputDebugStringA("Error reading normal data.\n");
                std::stringstream ssc;
                ssc << loopcount;
                std::string str = ssc.str();
                OutputDebugStringA((char*)str.c_str());
                OutputDebugStringA("\n");
            }
            data3 = "";
            data2 = "";
        }

        var1 = data.find(uv);
        if(var1 != std::string::npos && var1 < data.size())
        {
            data3.append(data,3,std::string::npos);

            float v1,v2,v3;
            std::istringstream ss(data3);
            if(ss >> v1 >> v2){ u.push_back((float)v1); u.push_back((float)v2); u.push_back((float)v3); k++;}
            else
            {
                OutputDebugStringA("Error reading UV data.\n");
                std::stringstream ssc;
                ssc << loopcount;
                std::string str = ssc.str();
                OutputDebugStringA((char*)str.c_str());
                OutputDebugStringA("\n");

            }
            data3 = "";
            data2 = "";

        }

        var1 = data.find(face);
        if(var1 != std::string::npos && var1 < data.size())
        {   
            data3.append(data,2,std::string::npos);
            std::istringstream ss(data3);

                for(int l = 0;l < data3.size();l++)
                {
                    if(data3[l] == '/') data3[l] = ' ';
                }

            std::istringstream ss(data3);
            unsigned int verts[9];
            char slashes[6];

                //if(ss >> verts[0] >> slashes[0] >> verts[1] >> slashes[1] >> verts[2] >> verts[3] >> slashes[2] >> verts[4] >> slashes[3] >> verts[5] >> verts[6] >> slashes[4] >> verts[7] >> slashes[5] >> verts[8])
            if (ss >> verts[0] >> verts[1] >> verts[2] >> verts[3] >> verts[4] >> verts[5] >> verts[6] >> verts[7] >> verts[8])
                else
                {
                    try
                    {
                    tV.push_back(v.at(verts[0]));
                    tV.push_back(v.at(verts[0]+1));
                    tV.push_back(v.at(verts[0]+2));

                    tU.push_back(u.at(verts[1]));
                    tU.push_back(u.at(verts[1]+1));
                    tU.push_back(u.at(verts[1]+2));

                    tN.push_back(n.at(verts[2]));
                    tN.push_back(n.at(verts[2]+1));
                    tN.push_back(n.at(verts[2]+2));
                    //
                    tV.push_back(v.at(verts[3]));
                    tV.push_back(v.at(verts[3]+1));
                    tV.push_back(v.at(verts[3]+2));

                    tU.push_back(u.at(verts[4]));
                    tU.push_back(u.at(verts[4]+1));
                    tU.push_back(u.at(verts[4]+2));

                    tN.push_back(n.at(verts[5]));
                    tN.push_back(n.at(verts[5]+1));
                    tN.push_back(n.at(verts[5]+2));
                    //
                    tV.push_back(v.at(verts[6]));
                    tV.push_back(v.at(verts[6]+1));
                    tV.push_back(v.at(verts[6]+2));

                    tU.push_back(u.at(verts[7]));
                    tU.push_back(u.at(verts[7]+1));
                    tU.push_back(u.at(verts[7]+2));

                    tN.push_back(n.at(verts[8]));
                    tN.push_back(n.at(verts[8]+1));
                    tN.push_back(n.at(verts[8]+2));
                    }
                    catch(std::out_of_range e)
                    {
                        OutputDebugStringA("Out of Range!\n");
                    }
                }
            }
            else
            {
                OutputDebugStringA("Invalid face data! Generic     Error!\n");
                std::stringstream ssc;
                std::stringstream ssc2;

                ssc << loopcount;
                std::string str = ssc.str();
                OutputDebugStringA((char*)str.c_str());
                OutputDebugStringA("\n");
            }

            data3 = "";
            data2 = "";
        }
        loopcount++;

    }

}
else
{

}
}

好的，我修复了斜杠问题，但现在这段代码导致std:：out_of_range异常：

                tV.push_back(v.at(verts[0]));
                tV.push_back(v.at(verts[0]+1));
                tV.push_back(v.at(verts[0]+2));

                tU.push_back(u.at(verts[1]));
                tU.push_back(u.at(verts[1]+1));
                tU.push_back(u.at(verts[1]+2));

                tN.push_back(n.at(verts[2]));
                tN.push_back(n.at(verts[2]+1));
                tN.push_back(n.at(verts[2]+2));
                //
                tV.push_back(v.at(verts[3]));
                tV.push_back(v.at(verts[3]+1));
                tV.push_back(v.at(verts[3]+2));

                tU.push_back(u.at(verts[4]));
                tU.push_back(u.at(verts[4]+1));
                tU.push_back(u.at(verts[4]+2));

                tN.push_back(n.at(verts[5]));
                tN.push_back(n.at(verts[5]+1));
                tN.push_back(n.at(verts[5]+2));
                //
                tV.push_back(v.at(verts[6]));
                tV.push_back(v.at(verts[6]+1));
                tV.push_back(v.at(verts[6]+2));

                tU.push_back(u.at(verts[7]));
                tU.push_back(u.at(verts[7]+1));
                tU.push_back(u.at(verts[7]+2));

                tN.push_back(n.at(verts[8]));
                tN.push_back(n.at(verts[8]+1));
                tN.push_back(n.at(verts[8]+2));

---

似乎使用

>

从istream进行解析并不像您所期望的那样有效。您是否注意到它在解析顶点、法线和UV时自动跳过空白？然而，对于人脸，您尝试解析每个字符。您还需要非空白斜杠作为分隔符

---

这种方法怎么样？一个答案建议告诉流将逗号（在您的例子中是斜杠）视为空白，这样您就可以像解析顶点一样轻松地解析面。另一个答案是建议使用字符串标记器，如StrTk或Boost。

请告诉我们问题出在哪里？你说的“脸根本没有被读取”是什么意思？如果我说得不清楚，很抱歉，包含ss>>verts[0]>>slash[0]的if语句失败了。与之关联的else语句打印出“无效的面部数据！”。您必须使用自己编写的解析器吗？我最近使用了一个非常好的解析器，我建议您看看它@TheMateurProgrammer感谢您的链接！我只是觉得这将是一个很好的练习，只是写自己，也许学习一两件事。好的，我接受了你的建议，但我没有使用任何这些链接。我搜索了包含当前行的字符串，并将斜杠变成了空格“/”到“”。现在我得到了*std:：out_of_range异常。@NickEllas这是因为OBJ文件中面的u/v和法线参照超出了范围。例如，法线10，但仅定义了一个法线。我猜这些索引指的是行号或第n个元素。法线是OBJ文件中的第十个元素。

                tV.push_back(v.at(verts[0]));
                tV.push_back(v.at(verts[0]+1));
                tV.push_back(v.at(verts[0]+2));

                tU.push_back(u.at(verts[1]));
                tU.push_back(u.at(verts[1]+1));
                tU.push_back(u.at(verts[1]+2));

                tN.push_back(n.at(verts[2]));
                tN.push_back(n.at(verts[2]+1));
                tN.push_back(n.at(verts[2]+2));
                //
                tV.push_back(v.at(verts[3]));
                tV.push_back(v.at(verts[3]+1));
                tV.push_back(v.at(verts[3]+2));

                tU.push_back(u.at(verts[4]));
                tU.push_back(u.at(verts[4]+1));
                tU.push_back(u.at(verts[4]+2));

                tN.push_back(n.at(verts[5]));
                tN.push_back(n.at(verts[5]+1));
                tN.push_back(n.at(verts[5]+2));
                //
                tV.push_back(v.at(verts[6]));
                tV.push_back(v.at(verts[6]+1));
                tV.push_back(v.at(verts[6]+2));

                tU.push_back(u.at(verts[7]));
                tU.push_back(u.at(verts[7]+1));
                tU.push_back(u.at(verts[7]+2));

                tN.push_back(n.at(verts[8]));
                tN.push_back(n.at(verts[8]+1));
                tN.push_back(n.at(verts[8]+2));