A part that can contain other parts, such as a Window part, has a grid associated with it. You can use this grid to align and space the child parts evenly within the parent part.
To toggle between showing and hiding the grid, select the part, and then
select the Toggle Grid tool
from the toolbar or select Toggle Grid from the parts pop-up
menu.
To specify the grid spacing of a part, select Set Grid Spacing from the part's pop-up menu. In the Set Grid Spacing window, specify the horizontal and vertical distance between the lines of the grid.
You can automatically position a part to the nearest grid coordinate when it is added to the free-form surface or moved by selecting Snap On Drop from the Options menu.
To position the top-left corner of child parts to the nearest grid coordinate of the parent part: