Building Grids

User-defined building grids facilitate the modeling of surface, girder grillage, or lattice structures. The intersections of a planar or spatial grid of lines provide definition points for lines, members, and surfaces. You can use the building grid to place objects when the object snap is activated with the 'Building grid' option (see chapter Object snaps). This can also be quickly controlled with the button in the CAD toolbar .

Four grid types are preset, which you can adjust as needed and use for input.

Preset Types for Building Grids

In the 'New Building Grid' dialog box, you can create a user-defined grid.

Dialog Box "New Building Grid"

The Active check box controls whether the selected grid is displayed in the work window.

Base

In the Base tab, you make the basic specifications for the building grid.

Grid Line Coordinates

In this section, enter the position coordinates of the grid lines. Use spaces as separators (see 'New Building Grid' dialog box). Make sure that the coordinates are in a consistently ascending or descending order.

For a regular grid, enter the coordinate of the first line. Then add the number of additional grid lines and multiply the value by the distance (example: 4*5.000 means "four more lines, each at a distance of 5.000 m").

If you create a Specific Grid by a rotation (cylindrical or spherical), you can define the rotation angles and distances in the adjusted input boxes.

Grid Line Designations

In this section, specify the designations with which the grid lines are to be labeled. The preset entries are automatically completed when you insert coordinates in the section above. Here, too, the tooltip provides useful hints.

Origin

Define the zero point of the grid at an existing or new 'Node'. You can also place the origin at any point by entering its coordinates or by graphically defining the point using the button .

Options

In this section, you can influence the display of the building grid:

• Lock in graphic: The grid cannot be moved graphically.
• Consider when 'Show Entire Model': The grid is displayed in the overall view.
• Grid points: The intersections of the grid lines are displayed.
• Grid lines: The grid lines are displayed.
• Designations: The labels of the grid lines are displayed if the options for the 'Designations' are activated for the grid line start and grid line end.
• Dimensions: The dimensioning of the grid points is displayed.
• Specific grid: The line grid can be inclined, rotated, or aligned to a reference object (see tab Specific Grid).

Grid Line Start / Grid Line End

With a 'Line extension', you can extend the grid lines beyond the boundary intersections of the lines. Enter the dimensions for the relevant axes in each case.

Grids Without Line Extension (Left) and with Line Extension (Right)

The check boxes for the 'Designation' control whether the labels are displayed on the grid lines and for which axes and line ends this should be done.

Specific Grid

The Specific Grid tab is displayed if you have checked the 'Specific grid' option in the 'Base' tab. Here you can change the grid type, rotate the grid, or align it to another object.

Aligning Building Grid Specifically

Types

The 'Grid type' describes the basic geometric shape of the building grid. The following options are available in the list:

• Cartesian: The grid is created in the Cartesian coordinate system.
• Inclined: The orthogonally aligned grid is rotated by an inclination angle.
• Cylindrical: The grid is created by a rotation of points about the Z-axis.
• Spherical: The grid is created by a rotation of points about two axes.

Define the 'Coordinate system' to which the building grid refers. You can select a user-defined coordinate system from the list or create a new one with the button .

The 'Rotation type' defines how the rotation of the building grid is to be performed. The following options are available in the list:

• Rotated by 3 angles: Rotation of the grid about the global axes with the angles α_X', α_Y', and α_Z'
• Directed to node: Orientation of the grid axes X' and Y' to a node
• Parallel to two nodes: Orientation of the grid to the connection line of two nodes
• Parallel to coordinate system of line / Parallel to coordinate system of member: Orientation of the grid to the local axes of a line or member

Rotation Parameter

This section is adapted to the 'Rotation type'. Here you can define the objects or rotation angles.

Inclination Angle

This section is displayed for the 'Inclined' grid type. Here you can define the rotation angles α about the X, Y, and Z axes.