我將角軸表示轉換爲歐拉角。我決定檢查並確保從轉換中得到的歐拉角度會回到原來的軸角度。我打印出這些值,但它們不匹配!我已閱讀http://forum.onlineconversion.com/showthread.php?t=5408和http://en.wikipedia.org/wiki/Conversion_between_quaternions_and_Euler_angles以及本網站上的類似轉換問題。將四元數轉換爲歐拉角和返回的不正確
在下面的代碼中,我從角度'angle'和軸(rx,ry,rz)開始,然後將其轉換爲四元數(q0,q1,q2,q3)。我將四元數轉換成歐拉角(滾動,俯仰,偏航)。然後檢查它,我將(滾動,俯仰,偏航)轉換回軸角爲cAngle和(cRx,cRy,cRz)。然後我做一些邊界檢查(滾動,俯仰,偏航)以保持-pi和pi之間的數字,然後將它們打印出來。應該是cAngle =角度和(cRx,cRy,cRz)=(rx,ry,rz),但這些都是錯誤的。
我相信旋轉的順序是Z * Y * X。我的數學有什麼問題嗎?我打算最終在pitch爲0或PI爲http://www.euclideanspace.com/maths/geometry/rotations/conversions/quaternionToEuler/時添加特殊情況,但現在我認爲問題是分開的。
//input is angle 'angle' and axis '(rx,ry,rz)'
//convert rx,ry,rz, angle, into roll, pitch, yaw
double q0 = Math.Cos(angle/2);
double q1 = Math.Sin(angle/2) *Math.Cos(rx);
double q2 = Math.Sin(angle/2) * Math.Cos(ry);
double q3 = Math.Sin(angle/2) * Math.Cos(rz);
double roll = Math.Atan2(2 * (q0 * q1 + q2 * q3), 1 - 2 * (q1 * q1 + q2 * q2));
double pitch = Math.Asin(2 * (q0 * q2 - q3 * q1));
double yaw = Math.Atan2(2 * (q0 * q3 + q1 * q2), 1 - 2 * (q2 * q2 + q3 * q3));
//convert back to angle axis
double cAngle = 2 * Math.Cos(Math.Cos(roll/2) * Math.Cos(pitch/2) * Math.Cos(yaw/2) + Math.Sin(roll/2) * Math.Sin(pitch/2) * Math.Sin(yaw/2));
double cRx = Math.Acos((Math.Sin(roll/2) * Math.Cos(pitch/2) * Math.Cos(yaw/2) - Math.Cos(roll/2) * Math.Sin(pitch/2) * Math.Sin(yaw/2))/Math.Sin(cAngle/2));
double cRy = Math.Acos((Math.Cos(roll/2) * Math.Sin(pitch/2) * Math.Cos(yaw/2) + Math.Sin(roll/2) * Math.Cos(pitch/2) * Math.Sin(yaw/2))/Math.Sin(cAngle/2));
double cRz = Math.Acos((Math.Cos(roll/2) * Math.Cos(pitch/2) * Math.Sin(yaw/2) - Math.Sin(roll/2) * Math.Sin(pitch/2) * Math.Cos(yaw/2))/Math.Sin(cAngle/2));
//stay within +/- PI of 0 to keep the number small
if (roll > 3.1416) roll = -Math.PI + (roll - Math.PI);
if (roll < -3.1416) roll = Math.PI + (roll - (-1) * Math.PI);
if (pitch > 3.1416) pitch = -Math.PI + (pitch - Math.PI);
if (pitch < -3.1416) pitch = Math.PI + (pitch - (-1) * 3.1416F);
if (yaw > 3.1416) yaw = -Math.PI + (yaw - Math.PI);
if (yaw < -3.1416) yaw = Math.PI + (yaw - (-1) * Math.PI);
Console.WriteLine("original angle, axis " + angle + ": " + rx + ", " + ry + ", " + rz);
Console.WriteLine("converted angle, axis " + cAngle + ": " + cRx + ", " + cRy + ", " + cRz);
Console.WriteLine("quats " + q0 + ", " + q1 + ", " + q2 + ", " + q3);
Console.WriteLine("roll,pitch,yaw: " + roll + ", " + pitch + ", " + yaw);
+1。我終於知道四元數是什麼。更多信息在一分鐘內比谷歌天。希望你得到你的答案。 – Kaliber64 2013-02-24 00:55:43