Slab Command

Overview

The “Slab Command” adds a new IfcSlab instance to the model.

The slab is created as an extruded solid. Unlike the other element commands, the slab
does not use an IfcProfileDef. Its outline is the polygon you specify in the view, and
the outline is extruded downwards by the value of the “Thickness” property. In other
words the points you specify describe the top face of the slab.
The outline is projected onto the horizontal plane that passes through the first point,
so the height of the slab is taken from the first point only.
The new slab is added to the building storey selected in the “Storey” property.

Specifying the outline of a slab in the 3D view. The marker shows the “Surface point”
object snap picking up a point on the surface below.

The command can be started in any of the following ways:

1. Click the “Slab” button on the Elements panel of the Home tab.
2. Enter “_CliCmdCreateBuildingElementSlab” (or its alias “slab”) in the prompt window.

Usage

Here is an explanation of how the “Slab Command” is typically used:

1. Start the command. The Property View switches to the settings of the command.

2. Check the settings in the Property View and change them if necessary. At least
   “Storey” must be set, otherwise the command reports an error.

3. Specify the first corner of the outline when the prompt “1st position” is displayed.

4. Specify the remaining corners one by one when the prompt “Next position” is
   displayed.

5. Close the outline in any of the following ways. The slab is created and the #id
   of the new instance is printed in the prompt window.

   • Specify the first point again. The first point is offered as the default value of
     the prompt, so simply pressing the Enter key does the same.
   • Enter “C” in the prompt window. This choice is offered as “Close(C)” in the prompt
     once three or more corners have been specified.

6. Continue specifying outlines to place further slabs. Press Esc to finish the command.

At least three corners are required. The settings you used are stored, so the next time
the command is started the same thickness and storey are offered again.

While you are specifying the corners, the outline being entered is previewed in the view
together with the thickness, so you can see the shape of the slab before it is created.

Controls

Messages

The following messages are displayed in the prompt window when the input is not valid.

Command Name

_CliCmdCreateBuildingElementSlab

Alias

slab