The Grid Justification tool defines the origin of the grids on the surface. Both U and V grids are centered in a surface by default, but each can be repositioned to the left and right, as well as top and bottom, resulting in the following 9 possible locations for grid justification.
Top Left |
Top Center |
Top Right |
Left Center |
Center |
Right Center |
Bottom Left |
Bottom Center |
Bottom Right |
The Grid Justification tool will snap to any of these locations on a surface. In the following illustration, notice how the positioning of the Grid Justification tool adjusts the location of the UV grids.