一.四元数&欧拉角

import bpy
import mathutils

quat = mathutils.Quaternion((0.7071068, 0.0, 0.7071068, 0.0))
euler = quat.to_euler('XYZ'))
quat = euler.to_quaternion()

二.四元数&旋转矩阵

import bpy
import mathutils

quat = mathutils.Quaternion((0.7071068, 0.0, 0.7071068, 0.0))
matrix = quat.to_matrix()
quat = matrix.to_quaternion()

三.旋转矩阵变换

a = mathutils.Matrix.Identity(4)
b = mathutils.Matrix.Identity(4)

c = a @ b