Controls the preset (startup) grid size and options.
The number of subdivisions between grid lines. The subdivision lines are lighter than the normal grid lines, but you can still snap to them using grid snapping.
For example, if you set the grid spacing to 1.0, and the number of subdivisions to 4, Alias shows grid subdivisions at 0.25, 0.5, 0.75, 1.25, and so on.