Using Generic Label 18 to display customized element info

[Laszlo Nagy]

So, here is how to make a Label display the surface setting of a Wall in Elevation:

First, let me tell you what makes this possible.
The first part of the solution is the fact that in AC18 there is a new Label called Generic Label 18. This Label is capable of displaying lots of pieces of information about the element it labels, including any of the IFC Properties the given element has.

The other part of the solution is the fact that you can define your own custom IFC Properties for any of the 3D element types (like Walls, Slabs, Roofs, etc.) in the IFC Scheme Setup Dialog. For example, if you would like all Walls to have a certain custom IFC Property available to them in their Settings Dialog, you can define such a custom IFC Property in the IFC Scheme Setup Dialog for the IfcWall element of the IFC hierarchy (the IfcWall element is the IFC equivalent of ArchiCAD's Walls), and the newly defined custom IFC Property will be available for all Walls in the Wall Settings Dialog's Tags and Categories panel.

The third part is that now in AC18 it is possible to map any IFC Property (default, or custom defined by you) to contain a value composed of any combination of element parameters, object parameters and simple texts.

And the way these three parts come together in this specific case is:
1. You create a new custom IFC Property for Walls.
2. You map this new IFC property to contain the value of the desired Wall schedule parameter.
3. You set your Generic Label to display this new IFC Property.

The reason we need to use this method is because Labels cannot directly read and display the values of element schedulable parameters.

So step one:
Create a new custom IFC Property for your Walls.
0. Activate the File\File Special\IFC 2x3\IFC Scheme Setup Dialog.
On the left pane you can see the full IFC object tree structure.
1. Select the IfcWall element in the tree structure in the left pane. If is found under:
(IfcObjectDefinition)\(IfcObject)\(IfcProduct)\(IfcElement)\(IfcBuildingElement)\IfcWall
When you select IfcWall on the left, its IFC Properties will be displayed in the middle pane.
2. Click the New Property/Classification button.
3. In the appearing Dialog, select the Custom IFC Property radio button.
4. Type the desired name in the Property Set name field (e.g. WallSurfaces). This will be the Group under which the defined custom IFC Property will be placed. All those "Pset_..." items are groups under which IFC Properties are placed. So this is the name of the group.
5. In the Property name field, type the name you want to give to your custom IFC Property (e.g. Outside Surface).
Note: This text will be displayed in the Label so it is a good idea to use here the exact text you want to see later in the Label.
6. Other fields can keep their default settings. Click the OK button to leave this dialog.
When you have done it the new WallSurfaces group will be listed at the bottom and it will contain one new IFC Property called Outside Surface.

[Laszlo Nagy]

The next step is to create the IFC mapping for this newly created IFC Property.

1. Click the Outside Surface property in the WallSurfaces group in the middle pane to select it.
2. In the right pane, in the upper list click the New Rule button. An item called Empty Rule will appear in the list.
3. At the bottom of the right pane, click the Add Parameters button.
4. In the appearing Dialog you will see all Schedulable parameters you can also see in the Scheme Setup Dialog when defining Schemes for the Schedule. Expand the Wall group, then the Wall group under it again, then select the Outside Face Surface parameter in the list.
5. Click the Add button to add the parameter to the list on the right. Alternately, you can just drag-and-drop it into the list.
6. Click the OK button to accept these changes and leave the Dialog.

[Laszlo Nagy]

Now that the mapping is done the upper right field shows that the Outside Surface IFC Property will return the value of the Outside Face Surface parameter of the Wall.
Click the OK button in the IFC Scheme Setup Dialog to accept all Changes.

Note: In a similar way you can create a custom IFC Property for the Inside Surface of the Wall as well as you might need that one too.

[Laszlo Nagy]

Now, if you go to the Wall Settings Dialog and activate its Tags and Categories panel, you will see at the bottom that it has a new IFC Property called Outside Surface and its value is now properly filled out by ArchiCAD.

The IFC Property returns the value of the surface of the outside face of the Wall. This can come from the definition of the Building Material of the outermost skin of the Wall, or can come from the Model panel override setting for the outside face of the Wall, if you activated and set an override surface for it.

Our last step is to display these value in the Label.

[Laszlo Nagy]

To display the given IFC Property in a Label:


0. Select the Wall in the Elevation and check the Label Elements checkbox in the Info Box. Then select the displayed Label (it might only be a leader line with no text in the lower left corner of the Wall) then go to the Label Settings Dialog.
1. In the Content and Preview panel, the Wall Tool item is the only one in the list. (This means the Label settings you define now will be applied only to the selected Wall Label.)
2. Above the Preview field, click the long horizontal button and select Generic Label 18 from the list of available Labels.
3. In the Custom Settings panel, make sure the Content and Display Order page is displayed. For the 2. block select Additional Tags from the list (This is the option that lets you display IFC Properties of elements in Labels).
4. Click the Set Additional Tags button to the right of the 2. block field.
To be continued in next post.

[Laszlo Nagy]

In the Additional Tags page of the Custom Settings panel, click the right-pointing arrow at the right end of the 1. Row and select Outside Surface (WallSurfaces) from the list. Then click the OK button.

[Laszlo Nagy]

The value of the IFC Property is now displayed in the Label.

Some Notes:
* In the Symbol Label panel of the Label Setting Dialog, you can uncheck the Use Symbol Arrow checkbox, in which case the Label will draw a Leader Line and arrow.
* The 1. Block of the Generic Label is usually the ID field. But you can make the Additional Tags the 1. block instead of the ID, you don't have to always display the ID. Or you can select the ** Empty Row option for the 1. Row with the same result.
* At the bottom of the Content and Display Order page of the Custom Settings panel of the Label Settings Dialog, there is a Display Data by field. Here you can set to display only the Parameter Value if that is the desired output (this is the setting I used for the attached image).
* As you probably know it is possible to set default settings for Labels by going to the Label Settings Dialog with no Label element selected. However, in this case the list in the Additional Tags page will not be populated with IFC Properties. This is why you have to select a Label already displayed for a Wall and make your settings there.
* You can transfer the settings of one placed Label to another using ALT-click, then CTRL-ALT-click.

[Laszlo Nagy]

Here is also Nathan Hildebrand's video about IFC Mapping:

https://www.youtube.com/watch?v=u-LiZh9NSEo

[Link]

And of course Rob Jackson's take on IFC Mapping. The more people that see this stuff and start implementing it, the better.

http://bimblog.bondbryan.com/archicad-18-join-the-ifc-and-cobie-flow-part-2-data-mapping/

Cheers,
Link.