# Grid lines
The grid line definition dialog is used to define or modify the grid lines for the model.
Grid lines are defined as being in the global XY plane. Grid lines form part of the current grid and, when displayed, are projected onto the current grid plane (unless it is vertical). Grid lines can be displayed in Graphic Views and can be operated on using sculpt commands.
Grid lines may be straight or circular arcs.
- Straight grid lines are defined by a start position, a length and an angle
- Circular arc grid lines are defined by a centre of the arc, a radius, a start angle and an end angle
- Where the angles are measured from global X, anti-clockwise about global Z.
# Grid lines table
# Label
The name by which the grid line is referred. Labels must be unique.
# Arc
Specifies whether the grid line is a straight Line or circular Arc.
# X, Y
The start of a straight line or the centre of a circular arc, in global coordinates.
# Length
The length of a straight line or the radius of a circular arc.
# Theta 1
The angle of inclination of a straight line or the start angle of a circular arc, measured from global X, anti-clockwise about global Z.
# Theta 2
The end angle of a circular arc, measured from global X, anti-clockwise about global Z. (Not required for straight grid lines.)
# Add grid lines
This is a tool for generating new grid lines using as a basis the grid line that is currently selected in the table. If the increment value is positive the new grid lines are inserted below the current grid line; if negative, above.
The new grid lines are given unique labels, based on the label of the current grid line.
# Move grid lines
This tool moves the existing grid lines that are currently selected in the table. The grid lines may be translated in the x or y directions or rotated about the Z axis; the transformation occurs in the currently defined axes.
Note that only axes that have a vertical z axis are offered in the list of available axes.