我的 lookAt 和透视调用有什么不同 VS gluPerspective 和 glLookat(立方体拉伸)

Question

旁注:嘿大家，如果你觉得我的问题/答案有帮助，请不要忘记投票。

所以我对矩阵[投影和模型]的实现似乎有些不同(除了我为了调试目的而注释掉的东西)。下面是我在绘制立方体时看到的bug的截图。请记住，我确实保持视口和矩阵与窗口大小和计算屏幕比例的最新与float而不是int，所以不要麻烦问，我已经检查了通常的怀疑.....

屏幕截图

文件(linux版本，参见./build中的自述文件)
旁注:在调试时，我改变了立方体的距离。要重现屏幕截图，请在workspace.cpp的第76行将mDistance设置为大约90，并将窗口框架拉伸到窗口右下角所示的尺寸。

请记住屏幕截图和调试文本输出是单独的事件，因为我不断调试这个问题并获得新的数字。

代码:

#define _AP_MAA 0
#define _AP_MAB 1
#define _AP_MAC 2
#define _AP_MAD 3
#define _AP_MBA 4
#define _AP_MBB 5
#define _AP_MBC 6
#define _AP_MBD 7
#define _AP_MCA 8
#define _AP_MCB 9
#define _AP_MCC 10
#define _AP_MCD 11
#define _AP_MDA 12
#define _AP_MDB 13
#define _AP_MDC 14
#define _AP_MDD 15

设置相机视角:

void APCamera::setPerspective(GMFloat_t fov, GMFloat_t aspect, GMFloat_t near, GMFloat_t far)
{
   GMFloat_t difZ = near - far;
   GMFloat_t *data;
   mProjection->clear(); //set to identity matrix
   data = mProjection->getData();
   GMFloat_t v = 1.0f / tan(fov / 2.0f);
   data[_AP_MAA] = v / aspect;
   data[_AP_MBB] = v;
   data[_AP_MCC] = (far + near) / (difZ);
   data[_AP_MCD] = -1.0f;
   data[_AP_MDD] = 0.0f;
   data[_AP_MDC] = (2.0f * far * near)/ (difZ);
   mRatio = aspect;
   mInvProjOutdated = true;
   mIsPerspective = true;
}

设置摄像机方向:

bool APCamera::lookTo(Coordinate &to, Coordinate &from, Coordinate &up)  
 {
      Coordinate f, unitUp, right;  
      GMFloat_t *data;
      CoordinateOp::diff(&to, &from, &f);
      VectorOp::toUnit(&f, &f);
      VectorOp::toUnit(&up, &unitUp);
      VectorOp::cross(&f, &unitUp, &right);
      if((fabs(right.x) < FLOAT_THRESHOLD) && (fabs(right.y) < FLOAT_THRESHOLD) && (fabs(right.z) < FLOAT_THRESHOLD))
     {
         return false;
     }
     mCamPt = from;
     VectorOp::toUnit(&right, &mRight);
     mForward = f;
     VectorOp::cross(&mRight, &mForward, &mUp);
     mModelView->clear();
     data = mModelView->getData();
     data[_AP_MAA] = mRight.x;
     data[_AP_MBA] = mRight.y;
     data[_AP_MCA] = mRight.z;
     data[_AP_MAB] = mUp.x;
     data[_AP_MBB] = mUp.y;
     data[_AP_MCB] = mUp.z;
     data[_AP_MAC] = -mForward.x;
     data[_AP_MBC] = -mForward.y;
     data[_AP_MCC] = -mForward.z;
     //translation part is commented out to narrow bugs down, "camera" is kept at the center (0,0,0)
     //data[_AP_MDA] = (data[_AP_MAA] * -mCamPt.x) + (data[_AP_MBA] * -mCamPt.y) + (data[_AP_MCA] * -mCamPt.z);
     //data[_AP_MDB] = (data[_AP_MAB] * -mCamPt.x) + (data[_AP_MBB] * -mCamPt.y) + (data[_AP_MCB] * -mCamPt.z);
     //data[_AP_MDC] = (data[_AP_MAC] * -mCamPt.x) + (data[_AP_MBC] * -mCamPt.y) + (data[_AP_MCC] * -mCamPt.z);
  mInvViewOutdated = true;
  return true;
}  

调试输出:

LookTo (): & lt; 0, 0, 0>: & lt; 1, 0, 0>:
000000 - 000000


100万- 100万- 100万

setPerspective() fov:0.785398 ratio:1.185185 near:0.500000 far:100.000000
2.036993 0.000000 0.000000 0.000000
0.000000 2.4142.13 0.000000 0.000000
0.000000 -1.010050 -1.005025

Answer 1

最后，看起来麻烦制造者只是FOV。所以快速的答案是NO，我没有做任何与文档的角度不同的事情，看看函数。对于任何有类似问题的人，2.0f * atan(tan(DEFAULT_FOV_RAD/mRatio) * mRatio)为我做了这项工作。