Ansys Employee

Hi Gijoys4v,


Let me rephrase it and use the same image in the previous post. You can imagine the distance in the shifting direction as height, thus the origin point in the above figure is like the horizon, and the further away you move towards the negative Y direction, the higher you stand (because in the image negative Y direction is the shifting direction). So as a result, the red face is "higher" than the blue face, and that's why the red face is the high boundary and the blue face is the low boundary. 

Hopefully this makes sense