//Get an average (mean) from more then two quaternions (with two, slerp would be used).
//Note: this only works if all the quaternions are relatively close together.
//Usage:
//-Cumulative is an external Vector4 which holds all the added x y z and w components.
//-newRotation is the next rotation to be added to the average pool
//-firstRotation is the first quaternion of the array to be averaged
//-addAmount holds the total amount of quaternions which are currently added
//This function returns the current average quaternion
public static void AverageQuaternion(ref Vector4 cumulative, Quaternion newRotation, Quaternion firstRotation, int addAmount)
{
float w = 0.0f;
float x = 0.0f;
float y = 0.0f;
float z = 0.0f;
//Before we add the new rotation to the average (mean), we have to check whether the quaternion has to be inverted. Because
//q and -q are the same rotation, but cannot be averaged, we have to make sure they are all the same.
if (!Math3d.AreQuaternionsClose(newRotation, firstRotation))
{
newRotation = Math3d.InverseSignQuaternion(newRotation);
}
//Average the values
float addDet = 1f / (float)addAmount;
cumulative.w += newRotation.w;
w = cumulative.w * addDet;
cumulative.x += newRotation.x;
x = cumulative.x * addDet;
cumulative.y += newRotation.y;
y = cumulative.y * addDet;
cumulative.z += newRotation.z;
z = cumulative.z * addDet;
//note: if speed is an issue, you can skip the normalization step
//return NormalizeQuaternion(x, y, z, w);
}
//Get an average (mean) from more then two quaternions (with two, slerp would be used).
//Note: this only works if all the quaternions are relatively close together.
//Usage:
//-Cumulative is an external Vector4 which holds all the added x y z and w components.
//-newRotation is the next rotation to be added to the average pool
//-firstRotation is the first quaternion of the array to be averaged
//-addAmount holds the total amount of quaternions which are currently added
//This function returns the current average quaternion
public static void AverageQuaternion(ref Vector4 cumulative, Quaternion newRotation, Quaternion firstRotation, int addAmount)
{//Before we add the new rotation to the average (mean), we have to check whether the quaternion has to be inverted. Because
//q and -q are the same rotation, but cannot be averaged, we have to make sure they are all the same.
if (!Math3d.AreQuaternionsClose(newRotation, firstRotation))
{
newRotation = Math3d.InverseSignQuaternion(newRotation);
}
//Average the values
cumulative.w += newRotation.w;
cumulative.x += newRotation.x;
cumulative.y += newRotation.y;
cumulative.z += newRotation.z;
}
