[Python知识库]3维人脸重建(二)

组织架构

face3d 是一个基于python的3DMM工具包, 用matlab运行后generate.m, 生成三个东西,

具体里面是这样的:

• model
  

• model_info
  

• UV
  

代码分析

1. pipeline.py

• 代码是将3d model变为2d图片
  讲解一下其中的求取3d到2d图片的旋转矩阵的计算代码, 它实现了从3个输入角度计算出旋转矩阵R

def angle2matrix(angles):
    ''' get rotation matrix from three rotation angles(degree). right-handed.
    Args:
        angles: [3,]. x, y, z angles
        x: pitch. positive for looking down.
        y: yaw. positive for looking left. 
        z: roll. positive for tilting head right. 
    Returns:
        R: [3, 3]. rotation matrix.
    '''
    x, y, z = np.deg2rad(angles[0]), np.deg2rad(angles[1]), np.deg2rad(angles[2])
    # x
    # np.deg2rad返回一个数组, 就是角度转弧度 45转Π这种
    Rx=np.array([[1,      0,       0],
                 [0, cos(x),  -sin(x)],
                 [0, sin(x),   cos(x)]])
    # y
    Ry=np.array([[ cos(y), 0, sin(y)],
                 [      0, 1,      0],
                 [-sin(y), 0, cos(y)]])
    # z
    Rz=np.array([[cos(z), -sin(z), 0],
                 [sin(z),  cos(z), 0],
                 [     0,       0, 1]])
    
    R=Rz.dot(Ry.dot(Rx))
    return R.astype(np.float32)