Original Expressions
FQuat RotationQuat;
RotationQuat.W = CR*CP*CY + SR*SP*SY;
RotationQuat.X = CR*SP*SY - SR*CP*CY;
RotationQuat.Y = -CR*SP*CY - SR*CP*SY;
RotationQuat.Z = CR*CP*SY - SR*SP*CY;
It is clearly that
X, Y’s signs have been fliped.