Question about scene flow sign

[Hyeonjoong-Jang]

Hi, I reviewed the code and got one question.

In models/scene_flow_motion_field.py L256 and L257,

            flow_data_input['sflow_1_2'] = sf_1_2.permute(0, 2, 3, 1)[..., None, :]  # .fill_(0)
            flow_data_input['sflow_2_1'] = sf_1_2.permute(0, 2, 3, 1)[..., None, :]

is it supposed to be like this with a minus sign?

            flow_data_input['sflow_1_2'] = sf_1_2.permute(0, 2, 3, 1)[..., None, :]  # .fill_(0)
            flow_data_input['sflow_2_1'] = (-)sf_1_2.permute(0, 2, 3, 1)[..., None, :]

It is hard to understand without a minus sign because they are used in losses/scene_flow_projection.py L244 ~ L246.

        p1_camera_2 = torch.matmul(global_p1 + sflow_1_2 - t_2, R_2_T)
        p1_camera_2_static = torch.matmul(global_p1 - t_2, R_2_T)
        p2_camera_1 = torch.matmul(global_p2 + sflow_2_1 - t_1, R_1_T)

Maybe I missed something when I review your code.
What do you think?