Ho I'm sorry ... I just see that the code I sent was not the right one ... I
did some testing and suddenly the code had become anything ...
def slerp_quaternion(m_quaternion_1, m_quaternion_2, f_weight):
"""
!@Brief Apply Spherical interpolation between two quaternions.
@type m_quaternion_1: OpenMaya.MQuaternion
@param m_quaternion_1: First Quaternion.
@type m_quaternion_2: OpenMaya.MQuaternion
@param m_quaternion_2: Second Quaternion.
@type f_weight: float
@param f_weight: Value for blending.
"""
# Normalize quaternions
m_quaternion_1 = m_quaternion_1.normal()
m_quaternion_2 = m_quaternion_2.normal()
# If is equial return first quaternion
if m_quaternion_1.isEquivalent(m_quaternion_2):
return m_quaternion_1
# TODO: fixlater
# If the inputs are too close for comfort,
# linearly interpolate and normalize the result.
# if abs(dot) > 0.9995:
# pass
# If the dot product is negative, the quaternions
# have opposite handed-ness and slerp won't take
# the shorter path. Fix by reversing one quaternion.
# dot = dot_product(m_quaternion_1, m_quaternion_2)
dot = dot_product(m_quaternion_1, m_quaternion_2)
if dot < 0.0:
m_quaternion_2.negateIt()
dot *= -1.0
# Weight Blend
f_scale_1 = 1.0 - f_weight
f_scale_2 = f_weight
# Get Quaternion median
dot = max(min(dot, 1.0), -1.0)
f_theta = math.acos(dot)
f_sin_theta = math.sin(f_theta)
f_scale_1 = math.sin(f_scale_1 * f_theta) / f_sin_theta
f_scale_2 = math.sin(f_scale_2 * f_theta) / f_sin_theta
# New Quaternion
a_new_values = []
for i in xrange(4):
a_new_values.append(f_scale_1 * m_quaternion_1[i] + f_scale_2 *
m_quaternion_2[i])
return OpenMaya.MQuaternion(a_new_values[0], a_new_values[1],
a_new_values[2], a_new_values[3])
I do not get a better result. I wanted to use the function slerp of maya
but it is accessible only in c ++ not in python. So I make a slerp function
in python. The current problem is that as I can not know if my dot is
positive or negative. So I have a flip of 180 that is done on my rotation.
I understand better now with your explanation. I use the matrices to
retrieve quaternions. So I would have to retrieve the quaternions since the
euler rotations?
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