将矢量从 Y 向上翻转到 Z 时的旋转

Question

我有一个旋转问题。

我将相机设置为向上矢量是 Z，-X 是向前，右侧是 Y。我有在另一个坐标系中导出的模型，其中 Y 向上，-Z 向前，X 是正确的。

我的挑战/问题是轮换。在这种情况下如何在不更改我导入的对象的坐标系的情况下进行正确的旋转。规模和转型正在发挥应有的作用。

到目前为止，我已经尝试在旋转矩阵手册中交换 Y 和 Z 轴，分别做旋转矩阵，在我们读取控制文件时进行旋转，翻转 Z 和 Y 旋转轴，将矩阵更改为

| 1 0 0 |

| 0 0 1 |

| 0 1 0 |

等等。

PS。我不想更改我现在导入的对象文件的坐标系，当我在控制文件中写入 rotateY 时，它将在我的 Y 轴而不是对象 Y 轴上旋转对象。

这是我正在尝试转换的代码部分

// control file is where i store transform, rotate and scale in a text file and objects that i want to read. 
for(int i = 0; i< controls.size(); i++) {
        meshStruct tempMesh;

        int isMeshLoaded = loadObjFile((char*)controls[i].path, &tempMesh.objectInfo_, &tempMesh.numObjects_);
        if(isMeshLoaded)
        {
            cout<< "Mesh " << controls[i].path << " loaded sucesfully." << endl;
        } else {
            cout<< "Mesh " << controls[i].path << " loaded failed." << endl;
        }

        tempModelMatrix = mat4(1.0f, 0.0f, 0.0f, 0.0f,
                                0.0f, 1.0f, 0.0f, 0.0f,
                                0.0f, 0.0f, 1.0f, 0.0f,
                                0.0f, 0.0f, 0.0f, 1.0f);

        //mat4 tempModelMatrixFlip = mat4(1.0f, 0.0f, 0.0f, 0.0f,
        //                              0.0f, 0.0f, 1.0f, 0.0f,
        //                              0.0f, 1.0f, 0.0f, 0.0f,
        //                              0.0f, 0.0f, 0.0f, 1.0f);
        //tempModelMatrix *= tempModelMatrixFlip;

        tempModelMatrix = glm::translate(tempModelMatrix, controls[i].translate);

        tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.x), vec3(1.0, 0.0, 0.0));
        // I dont want to flip here Y and Z because some objects are in the correct coordinate system
        tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.y), vec3(0.0, 1.0, 0.0));
        tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.z), vec3(0.0, 0.0, 1.0)); 
        /*
        mat4 r  = mat4(1.0f);
        mat4 rx = mat4(1.0f); 
        mat4 ry = mat4(1.0f);
        mat4 rz = mat4(1.0f);
        rx = rotate(radians(controls[i].rotation.x), vec3(1.0, 0.0, 0.0));
        ry = rotate(radians(controls[i].rotation.y), vec3(0.0, 1.0, 0.0));
        rz = rotate(radians(controls[i].rotation.z), vec3(0.0, 0.0, 1.0));
        r = rx * ry * rz;       

        vec4 temp;

        temp = column(r, 1);
        cout << to_string(temp) << endl;
        r = column(r,1, column(r, 2));
        r = column(r,2, temp);

        temp = row(r,1);
        r = row(r, 1,row(r,2));
        r = row(r, 2, temp);
        //cout << to_string(column(tempModelMatrix, 1)) << endl;

        //tempModelMatrix *= r;
        float tempModelMatrix2[16];// = mat4(1.0f);

        tempModelMatrix2[0] =  controls[i].scale.x * column(r, 0).x;//controls[i].scale.x * controls[i].rotation.x;
        tempModelMatrix2[1] =  controls[i].scale.x * column(r, 0).y;//controls[i].scale.x * controls[i].rotation.x;
        tempModelMatrix2[2] =  controls[i].scale.x * column(r, 0).z;//controls[i].scale.x * controls[i].rotation.x;
        tempModelMatrix2[3] =  0.0f;
        tempModelMatrix2[4] =  controls[i].scale.y * column(r, 2).x;//controls[i].scale.y * controls[i].rotation.y;
        tempModelMatrix2[5] =  controls[i].scale.y * column(r, 2).y;//controls[i].scale.y * controls[i].rotation.y;
        tempModelMatrix2[6] =  controls[i].scale.y * column(r, 2).z;//controls[i].scale.y * controls[i].rotation.y;
        tempModelMatrix2[7] =  0.0f;
        tempModelMatrix2[8] =  controls[i].scale.z * column(r, 1).x;//controls[i].scale.z * controls[i].rotation.z;
        tempModelMatrix2[9] =  controls[i].scale.z * column(r, 1).y;//controls[i].scale.z * controls[i].rotation.z;
        tempModelMatrix2[10] = controls[i].scale.z * column(r, 1).z;//controls[i].scale.z * controls[i].rotation.z;
        tempModelMatrix2[11] = 0.0f;
        tempModelMatrix2[12] = controls[i].translate.x;
        tempModelMatrix2[13] = controls[i].translate.y;
        tempModelMatrix2[14] = controls[i].translate.z;
        tempModelMatrix2[15] = 1.0f;*/

        tempModelMatrix = glm::scale(tempModelMatrix, controls[i].scale);
        //cout << controls[i].path << " controls[i].translate " << to_string(controls[i].translate) << endl;
        //cout << controls[i].path << " controls[i].rotation.X " <<  controls[i].rotation.x << endl;
        //cout << controls[i].path << " controls[i].rotation.y " <<  controls[i].rotation.y << endl;
        //cout << controls[i].path << " controls[i].rotation.Z " <<  controls[i].rotation.z << endl;
        //cout << controls[i].path << " controls[i].scale " << to_string(controls[i].scale) << endl;

        string basedir = dirname(controls[i].path);
        for(int j = 0; j < tempMesh.numObjects_; j++){
            //tempMesh.objectInfo_[j].modelMatrix = controls[i].modelMatrix;
            tempMesh.objectInfo_[j].modelMatrix = tempModelMatrix;
            //tempMesh.objectInfo_[j].modelMatrix = make_mat4(tempModelMatrix2);

Answer 1

由于我无法确定您如何存储对象中的顶点数据，因此我将定义一些简单的东西：

struct Vertex {
    glm::vec3 position;
};

struct Mesh {
    std::vector<Vertex> vertices;
};

现在遍历所有顶点位置并将它们转换为您的世界坐标：

Mesh originalMesh = loadObjectFromFile("object.file");
Mesh convertedMesh = Mesh();

for (Vertex v : originalMesh.vertices) {
    convertedMesh.push_back(glm::vec3(v.y, v.z, v.x));
}

这里要注意的关键是我们正在执行以下映射：

x = v.y
y = v.z
z = v.x

如果您有其他顶点数据（例如法线、texcoords），请确保它们也被转换。

Answer 2

在与教授通过一些电子邮件后修复了计算旋转矩阵时出现小错误的问题。我是用相反的方式做的

tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.x), vec3(1.0, 0.0, 0.0));
tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.y), vec3(0.0, 1.0, 0.0));
tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.z), vec3(0.0, 0.0, 1.0)); 

而不是

tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.z), vec3(0.0, 0.0, 1.0));
tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.y), vec3(0.0, 1.0, 0.0));
tempModelMatrix = glm::rotate(tempModelMatrix, radians(controls[i].rotation.x), vec3(1.0, 0.0, 0.0));

感谢@Exide 的建议