Why rot_y multiply by -1 in flipping augumentation?

[nannanmath]

I found the code like:

Paddle3D/paddle3d/transforms/target_generator.py

Lines 278 to 280 in 3259dab

	if flipped:
	locs[0] *= -1
	rot_y *= -1

Why the rot_y multply by -1 after horizontal flipping augumentation?
I feel the rot_y should be:

if rot_y < 0:
  rot_y = -np.pi - rot_y
else:
  rot_y = np.pi - rot_y

Is it correct or I'm missing something?