Recently, we have noticed projects exporting IFC files incorrectly; specifically with missing content. Wether this is due to changes to ARCHICAD from IFC2x3 to IFC4, or if it is just a modeling error on our part, is difficult to pinpoint at this time. What we have determined is the issue is the result of Element Classification going missing.
The Element Classification is the little drop down at the bottom of the settings dialogue for each model element. You can locate this within the Categories and Properties tab of the element settings.
It can be easy to ignore this setting, since it really doesn’t impact our typical model or document process. But for IFC coordination this setting is critical. If this goes missing, the element will not save out.
rafter/purlins not cassified
all objects correctly classified
So a missing or undefined classification can get in the way of effective collaboration, but so can an incorrect classification. An example I have seen is doors that were used as gable end vents/walls. Because the door’s classification was left as “Door”, it was read as a door on the Revit side. This resulted in the door and the wall were defined as an opening that penetrated the roof; the engineer had to ask for a correction from our end.
IFC Classifications can seem a little confusing, given the unclear and vague terminology used in describing each classification. But fortunately Bond Bryan has already done the leg work to define each element classification and what is included. I have in turn reinterpreted this list in our BIM Manual for our calibre of projects; you can view this Dictionary of Element Classifications under Collaboration > IFC Classification in our BIM Manual. Or for a more complete list of building components and their Classifications, see Rob’s list here.
If you have adjusted edge surfaces of a slab or roof and want to make them uniform, there is an apply to all check box in the element selection settings. This option is also available for morphs using multiple surfaces on a single element. The check box is at the bottom of the element selection settings (Com + T on most work environments), and appears when you change a surface type for an element using multiple surfaces.
There is an indication that multiple surfaces have been used for a specific surface override shown as a yellow/red square stack to the left of the override setting.
For some, this may be getting ahead a bit. If you are unfamiliar with editing individual faces of a morph, slab or roof here are the methods for each:
For Morph Elements, hold Cntrl + Shift and click on a morph face(s). Then open the selection settings (Com + T) and edit the surface. If a morph face is already using a desired surface you can use the pick up & inject parameter functions to “eye dropper” surface settings to individual morph faces.
For slab and roof settings simply click on the edge of the reference plane and select the top right icon on the pet palette, or the “Custom Edge Settings” button.
Depending on wether the edge is part of a roof or slab, you will get different options in the resulting dialogue, but the surface adjustments are available for both:
You may notice that when you change an elements home story in the element selection settings, the elevation (height to project 0) also changes, or more accurately remains the same relative to its home story. This means that if you move a slab from the first floor to the second floor, it will move up the difference in the story settings.
Home story changed from Story 2 to Story 3 (Please ignore the sloppy 3/64″ modeling)
Walls jump to story 3 with same relationship to home story
If, however, you need to locate an element to a new story, but maintain its relationship to project 0, so that it stays at the same elevation but is located on a new story, you will need to relink the elements home story. This is done with a simple right click function, rather than in the element settings. Simply select the elements you want to change the story settings of, right click, select Relink Home Story… and the elements will remain at the correct height/elevation, but be set to the new home story.
Right click after selecting the element to redefine the elements home story
The elements will remain in their original location
If your windows have a fill that is being changed by the renovation filter options or a background fill that is masking out elements below the window that you want to see on your plan, you can turn off the fills by changing them to the transparent pen.
In the Cadimage Window Selection Settings go to the Parameters tab, then scroll down to 9 Appearance. Next look for the Mask Pen settings and change this pen to 0(Transparent).
In Cadimage Windows/Doors for 17 there is only one Mask Pen, for AC18 you will have the option to have a background and foreground pen.
The result for both AC17 & 18 of changing the Mask Pen (Background Pen) to Pen 0 will be a sill view in plan that is transparent and will not be changed by the Renovation Override Styles.
It has recently been discovered that there is an apparent “change” to ArchiCAD’s vector tools. Where we used to be able to inject parameters between lines, polylines, arcs and splines; in AC v18 it doesn’t seem to act the same way.
There is a solution! In the selection settings for each tool check the box that says “Uniform Settings for Line Tools“.
Quick and easy you are able to inject parameters from a polyline to a line or spline or arc. If you are not aware that this was an option, be sure this box is checked in all your vector tools selection settings and start using the inject parameters features for even more element types.
Recently we were looking for parameters for a door schedule, but could not find them in the standard schedule scheme settings. If this happens they most likely will be located in the additional object parameters or the additional IFC properties.
In the schedule Scheme Settings, click the down arrow to the right of the “Add” button (bottom left corner of the dialog box. This will give you a search box for the above mentioned additional parameters/properties. Virtually anything in an objects selection settings and IFC settings can be scheduled, you just need to find the object within the additional object parameters menu.
A quick way to find these objects is to be sure to save the object as a favorite, or to use the appropriate favorites from the start. By using the favorites and having the correct favorites palette loaded you will be able to search for specific objects by the favorites list. Once you have the object selected it is a simple task to search through the schedule-able fields and find the category you want to add. If it shows up in an objects selection settings dialog box it should show up in the favorites Additional Object Parameters dialog box.
The parameters we were searching for were the “User Defined” elements of a Cadimage door. Using these, rather than the default “Custom Text”, we were able to have custom fields that tied directly to the door object rather than a global Custom Text. These User Defined list items were located in the favorites list under the Cadimage Door object.