Start Position and Height of the Ladder

The user must first select the position and height of the ladder, the default position is the origin of the level with an upward (U) direction with respect to the level and a height of 4500.

There are a number of methods to select the position and height of the ladder:

• Enter the values in the east, north and up fields of the Position frame. The user can also change the reference by entering the name of an existing element in the Wrt field. If the field is greyed out, click Padlock to unlock it. If the direction is locked, the bottom position is adjusted for the direction. Otherwise the direction is calculated between both positions. The height is always calculated between both positions.

• Click Pick Top Level to select the top position in the graphical view to invoke the Positioning Control window. The user is prompted to pick the position. To avoid changing a desired value in a field, click Padlock to lock it. If the direction is locked, the bottom position is adjusted for the direction. Otherwise the direction is calculated between both positions. The height is always calculated between both positions.

• Enter the absolute top level (wrt World) in the Top Level field. If the height is locked, the bottom level adapts. If the height is not locked, the height adapts.

• Click Pick level which invokes the Positioning Control window. Pick a position in the graphical view to set the top level. If the height is locked, the bottom level adapts. If the height is not locked, the height adapts.

• Enter the value of the height in the Height field. The top position is adjusted to suit the new height.

• Click Measure to measure the height to invoke the Positioning Control window. The user is prompted to pick the start and end of the ladder. The top position is adjusted to suit the new height.

• Enter the absolute bottom level (wrt World) in the Bottom Level field. If the height is locked, the level adapts. If the height is not locked, the height adapts.

• Click Pick level which invokes the Positioning Control window. Pick a position in the graphical view to set the bottom level. If the height is locked, the top level adapts. If the height is not locked, the height adapts.

• Enter the values in the Direction field. The direction is always shown with respect to the level. If the direction is locked, click Padlock to unlocked it. The end position is adjusted to suit the new direction and the existing height.

• Click Pick surface or edge to define direction to select the direction in the graphical view. The end position is adjusted to suit the new direction and the existing height. To reverse the direction, click Reverse Direction.

In the graphical view, the positions proposed are shown by an arrow between the start and end.

Enter an angle in the Rotation field. An angle may have the following forms:

By default the rotation is zero.

Alternatively, click Rotate angle using two picks to invoke the Positioning Control window allowing the user to make graphically selections of existing elements to establish the rotation angle.

Click Apply to create the ladder. The Modification ladder window replaces the Creation Ladder window. Enter a valid name in the Name field to activate it.

To cancel the creation of the ladder, click Dismiss. If the user navigates to another element, the Modification Ladder window closes automatically.