Using the Grid

When working in MicroStation, you have the option of turning on the grid in any view. The grid consists of evenly-spaced points in the design plane. It is a visual measurement and alignment aid at certain magnifications.

Defined spacing between grid points and between grid references (highlighted grid points — every 12th point, for example) are collectively known as grid units. Grid unit settings are specific to each model in a DGN file. The appropriateness of grid unit settings for a design task is related to the size of the design, working units, and the required precision.

When used in conjunction with Grid Lock, the grid can assist in accurate “by eye” placement of elements (see Using Grid Lock). However, the grid can be an impediment to efficiently using AccuDraw.

Grid Orientation

You can define the orientation of the grid to suit the task at hand. Once you define a grid, Grid Lock works as expected and input points are constrained to the grid points. The Grid Orientation is controlled from the Grid section of the DGN File Settings dialog (select Settings > Design File). Options are:

• View — Grid always aligns to the view and passes through the global origin.

• ACS — Grid aligns to the active ACS.

• Top — Grid aligns to a “Top” view. It extends along the X and Y axes from the global origin.

• Right — (3D only) Grid aligns to a “Right” view. It extends along the Y and Z axes from the global origin.

• Front — (3D only) Grid aligns to a “Front” view. It extends along the X and Z axes from the global origin.

For 2D DGN files, only View, ACS, and Top are applicable. When Grid Orientation is set to anything other than View, then any view rotation will cause the grid to rotate as well.

A further option is a key-in that lets you rotate the grid about (its) Z-Axis. This key-in, ACTIVE GRIDANGLE <value> is included specifically to provide compatibility with AutoCAD, which supports only a grid in the XY plane, but can include a rotation angle.

To set up grid units

1. From the Settings menu, choose Design File.
   The DGN File Settings dialog box opens.


2. In the Category list box, select Grid.
   Controls for adjusting grid unit settings are displayed.

   DGN File Settings dialog box (Grid category). Grid Master means the number of grid points per master unit. Grid Reference means the number of grid points between grid references.



3. In the Grid Master field, enter the distance (in Working units) between points in the grid.


4. In the Grid Reference field, enter the number of grid points between grid references.


5. From the Grid Configuration option menu, choose one of these:

   Configuration	For grid points laid out as follows
   Orthogonal	Along lines perpendicular to design plane x-axis and y-axis
   Isometric	Along lines at 30° from design plane x-axis and y-axis
   Offset	Rows offset by half the distance between horizontal grid points



6. In the Grid Aspect field, key in the ratio of the distance between the grid points along the design x-axis and the distance between grid points along the y-axis.
   In the Isometric configuration, this ratio is fixed.


7. From the Orientation option menu, choose ACS, Top, or View (plus, in 3D, Front and Right).


8. Click the OK button.

To turn on or off the display of the grid in a view

1. From the Settings menu, choose View Attributes (or press <CTRL-B>).
   or
   From any view window's control menu, choose View Attributes.
   The View Attributes dialog box opens.

   View Attributes dialog box



2. From the View Number option menu, choose the number of the desired view.


3. Turn Grid on or off.


4. Click Apply.

To turn on or off the display of the grid in all views

1. From the Settings menu, choose View Attributes (or press <CTRL-B>).
   or
   From any view window's control menu, choose View Attributes.
   The View Attributes dialog box opens.


2. Turn Grid on or off.


3. Click All.

Using Grid Lock

When Grid Lock is on, all data points and tentative points are forced to fall precisely on a point in the grid.

To set Grid Lock

1. From the Settings menu's Locks submenu (or the pop-up Locks menu in the status bar) choose Full.
   The Locks dialog box opens.

   Locks dialog box



2. Turn Grid Lock on or off.

Alternative Method — To set Grid Lock

1. In the Settings menu's Locks submenu (or the pop-up Locks menu in the status bar), turn on Grid.