Calculating angle of 2D vector

[gmchoe]

Hi, Thank you for providing the optical flow plugin, I am now using it. But in velocitymaterial blueprint, 'calculating angle of 2D vector part', -2pi is multiplied by clamped sign and added to arctangent. I understand this part, but isn't -pi more correct instead of using -2pi? I just would like to discuss with you on this.

Thank you.

Chris.