Question

我是一个使用带有GLM库的现代OpenGL的初学者，我尝试用相机的运动（WSAD代表前进后退左右）和Q＆E（顺时针和逆时针）运动来创建键盘运动。

当我尝试在Y轴上旋转一整圈时，似乎旋转了一半，然后跳回到起点（想想是180度圆弧）。旋转会带来问题，但前进方向会带来问题，它会发生变化，而不是向前直线前进，而是在改变旋转角度时向前或向左或向右偏移。

    glm::vec3 eyepos = glm::vec3(-0.6f, -0.4f, 31.1f);
    glm::vec3 frontvector = glm::vec3(0.0f, 0.0f, -1.0f);//looking         pointing vector
    glm::vec3 lookvector = glm::vec3(0.0f, 0.0f, -1.0f);
    glm::vec3 flatupvec = glm::vec3(0.0f, 1.0f, 0.0f);
    glm::vec3 upvec = glm::vec3(0.0f, 1.0f, 0.0f);

    glm::mat4 viewmatrix;
    glm::mat4 projectionmatrix;//camera lens, projection matrix, need an                 aspect ratio function here /3D FOV

    GLfloat movespeed = 0.1f;
    GLfloat turnspeed = 1.0f;

    //********************MOVEMENT_TRANSFORMS***********************************
        if (kb.w == true) { eyepos += frontvector *  movespeed;         }   //move up
        if (kb.s == true) { eyepos -= frontvector *  movespeed; }   //move down
        if (kb.q == true) { glm::quat q =         glm::angleAxis(glm::radians(turnspeed),
            glm::vec3(0, 1, 0)); frontvector = (frontvector * q);         }//turn left (yaw)
        if (kb.e == true) { glm::quat q =         glm::angleAxis(glm::radians(-turnspeed), 
            glm::vec3(0, 1, 0)); frontvector = (frontvector * q);         }//turn right (yaw)
        if (kb.a == true) { eyepos -=         glm::normalize(glm::cross(frontvector, flatupvec)) * movespeed; }         //strafe left
        if (kb.d == true) { eyepos +=         glm::normalize(glm::cross(frontvector, flatupvec)) * movespeed; }         //strafe right
        if (kb.r == true) { eyepos += flatupvec * movespeed; }  //move         up
        if (kb.f == true) { eyepos -= flatupvec * movespeed; }  //move         down
                //********************ROTATIONS_EYEPOINT************************************
        if (kb.t == true) { glm::quat q = glm::angleAxis(turnspeed,         glm::vec3(1, 0, 0)); lookvector = q * lookvector; } //pitch up
        if (kb.g == true) { glm::quat q = glm::angleAxis(-turnspeed,         glm::vec3(1, 0, 0)); lookvector = q * lookvector; }//pitch down
        if (kb.z == true) { glm::quat q = glm::angleAxis(-turnspeed,         glm::vec3(0, 0, 1)); upvec = q * upvec; }  //roll left
        if (kb.x == true) { glm::quat q = glm::angleAxis(turnspeed,         glm::vec3(0, 0, 1)); upvec = q * upvec; }   //roll right
        if (kb.c == true) { glm::quat q = glm::angleAxis(turnspeed,         glm::vec3(0, 1, 0)); lookvector = q * lookvector; } //yaw left
        if (kb.v == true) { glm::quat q = glm::angleAxis(-turnspeed,         glm::vec3(0, 1, 0)); lookvector = q * lookvector; }//yaw right

        viewmatrix = glm::lookAt( eyepos, eyepos + frontvector + lookvector, upvec);
        projectionmatrix = glm::perspective(45.0f, 1.8f, 0.0001f, 500.0f);

Answer 1

问题是您的外观向量。您的函数通过说您在说（10,0,10）而工作，并且您正在看等于的（（10,0,10）+（0,0，-1）+（0,0，-1））（10,0,8）或直接向前。假设您看起来正确（（10,0,10）+（0.9,0，-0.1）+（0,0，-1））等于（10.9,0,8.9），而且一切大致还不错。但是假设您将其几乎变成等于（10.1,0,9.9）的最大值（（10,0,10）+（0.1,0,0.9）+（0,0，-1）），则比较为（10.1,0 ，9.9）和（10,0,8）到（10,0,10）仍然是相同的矢量（这可以解释180度圆弧）和（10,0,10）视点以及（10,0,10） lookat会模棱两可，因此您的问题是“ viewmatrix = glm :: lookAt（eyepos，eyepos + frontvector + lookvector，upvec）;”调用，并同时使用该程序同时包含frontvector和lookvector，您可能希望删除该调用的frontvector部分，但是要保留一些代码；）

在OpenGL4中旋转相机的问题

1 个答案: