Line Grids
User-defined line grids help you to model structures consisting of surfaces, girder grillages, or grids. The intersection points of the grid provide definition points for surfaces, lines, and members.
It is possible to use several line grids in one model.
Creating line grids
To open the dialog box for creating a new line grid, use the menu item
- Insert → Line Grid
or the shortcut menu in the Data navigator.
The Line Grid dialog box appears where you can define the new grid.
The Global Position of Insert Point defines the origin of the line grid.
The coordinates can be entered or selected in the work window with 
.
The Type dialog section below the dialog graphic provides the following options for defining the grid system before entering more data:
- Cartesian
- Spherical
- Inclined (grid can be rotated for each axis by any rotation angles γ)
- Cylindrical
The small graphic to the right is interactive with the type specification.
In the Line Grid in X-/Y-/Z-Direction dialog sections, enter the distances d and the Number of spans for each direction. The respective Name is preset but can be adjusted. It is also possible to enter the Coordinates of the distances or to adjust them retroactively.
The Positive and Negative options respectively determine, in which direction of the global axis the line grid is created.
In the Rotation dialog section, you can rotate the line grid about an axis:
First, select the Sequence that determines the order of the local grid axes X', Y', and Z'. Then, enter the angle of rotation about the global axes X, Y, and Z in the text boxes under Rotated about.
You can also use the 
buttons to define the support rotation graphically.
A large part of the dialog box is covered by a graphic window where the input is immediately displayed graphically. The buttons below the window are familiar from RFEM; they control the display of the dimensioning, numbering, axes, and view. It is also possible to use the mouse control options in this window (see Chapter 3.4.9).
Each line grid can be saved as a template and reused later. The buttons shown on the left are used to [Save] and [Load] the grid data.
After closing the dialog box, you can set objects at the grid nodes. Please make sure that the object snap is active for this (see Chapter 11.3.3).