As a cv beignner, I read the Data Generation of PIFu code, however, I get troubled in the code segment of sampleSphericalDirections, here is the code:
def sampleSphericalDirections(n):
xv = np.random.rand(n,n)
yv = np.random.rand(n,n)
theta = np.arccos(1-2 * xv)
phi = 2.0 * math.pi * yv
phi = phi.reshape(-1)
theta = theta.reshape(-1)
vx = -np.sin(theta) * np.cos(phi)
vy = -np.sin(theta) * np.sin(phi)
vz = np.cos(theta)
return np.stack([vx, vy, vz], 1), phi, theta
could you help do some explanation for me, thank you (I am Japanese, my English is pool.)
