制作一个IK定位骨骼模块

之前研究过这个问题，这是当时我计算极向量位置的解决方案

def computePolePos(ik_joints, **kwargs):
    offset_factor = kwargs.pop("offset", 5.0)
    coordinates = []
    for joint in ik_joints:
        joint_pos = pm.xform(joint, q=True, ws=True, t=True)
        coordinates.append(joint_pos)

    point_A = om.MPoint(coordinates[0][0], coordinates[0][1], coordinates[0][2], 1)
    point_B = om.MPoint(coordinates[1][0], coordinates[1][1], coordinates[1][2], 1)
    point_C = om.MPoint(coordinates[2][0], coordinates[2][1], coordinates[2][2], 1)

    vec_AC = om.MVector(point_C - point_A)
    vec_AB = om.MVector(point_B - point_A)

    cos = (vec_AC * vec_AB) / (vec_AC.length() * vec_AB.length())
    len_AD = vec_AB.length() * cos
    factor = len_AD / vec_AC.length()

    vec_AD = factor * vec_AC
    vec_DB = vec_AB - vec_AD

    loc = pm.spaceLocator()
    loc.visibility.set(False)
    pm.matchTransform(loc, ik_joints[1], pos=True)
    loc_pos = loc.getTranslation(space='world')
    loc.setTranslation(loc_pos + (offset_factor * dt.Vector(*vec_DB)), space='world')

    return loc