Cadgroup Revit.XT: Another day, another Calculated Parameter.

Written by Fadi Matti on . Posted in Architecture, BIM, Construction, Knowledge Base, Tech Tips.

Revit.XT is a subscription benefit for our valued Cadgroup customers. It has a wide array of tools built in that you can use to increase efficiency and enhance your documentation. It also has a very powerful tool that lets “interrogate” the Revit database in a powerful way. You can of course do this using Dynamo or perhaps scripting but the Calculated Parameters Tool in Revit.XT gives you access to these sorts of functions without having to get out of your comfort zone and it does it all within the Revit environment.

I had a customer the other day who wanted to be able to report the areas of Fill Regions in Revit. Of course, you can click on a Filled Region and Revit will show you the area but you can’t tag them or schedule them if you need to. I had a bit of a play with Revit.XT and was quickly able to come up with a solution:

  1. The first thing we need to do is create a new shared parameter. In this case, I went to the Manage Tab > Shared Parameters and made a new Parameter called “Fill Region Area” which I set as an “Area” format parameter.
  2. Either go into the Content Admin Tab (Revit.XT installs 2 tabs inside Revit) and use the Project Parameters tool to add the new parameter to “Detail Items” in the project OR use the Project Parameters tool that is built into Revit (under the Manage Tab > Project Parameters).
  3. In the dialogue box, pick the new parameter from the list of available shared parameters and make sure you assign this to Detail items.
  4.  When you select any Fill region, you will now see the new Parameter but it will be empty as Revit will not make a link between this Parameter and the “Area” parameter of the object. This is where Revit.XT comes into play!
  5. Inside Revit, go to the Content Admin Kit tab (this installs as part of Revit.XT). Select the “Manage Calculated Parameter” command and then in the dialogue box that comes up select an existing rule and click on the Duplicate Icon (I chose the “Empty Rule” to duplicate in my example below):
  6. Next, rename the rule. You can call it whatever you want but make it an name that you (and possibly other users) – in this case I called mine “Calculate Fill Region Areas”. In the next field below we add in the name of the Parameter that we want to push the sum of the calculated parameter into – so we pick the “Fill Region Area” Parameter. In the Formula window, we simply type in “Area” – in this case we are just “mapping the Revit Parameter that is built in to the Fill Region and pushing it into our new Parameter. Lastly, in the “Instance Selection” method, we’ll choose “From Model” – this will grab every Fill Region in the entire model and run the calculation for us – and lastly, make sure you pick “Detail Items” so that the calculations will be run on that Category of items:
  7.  To get the calculation to work we can either click on the “Update Calculated Parameter” command (which executes this any any other calculated parameters) or, to just exceute this one, go to the “Exectue Calculated Parameter” and choose our rule from the list by clicking on it:
  8. Now if you select any Fill Region in your model you’ll see the Parameter “Fill Region Area” reporting the “Area”. Now because we used a shared parameter, we have the ability to make a generic Tag and give it the category of “Detail Item”. We can then make a Label and pick our shared Parameter “Fill Region Area” and then we can place this into our Project and start tagging our Fill regions! Further to this, because this is a Shared Parameter, we can also create a detail Item schedule that lists the Areas.
  9.  Some things to remember. Like all things in Revit, Parameters and so forth are case sensitive. Always capitalise the first character of a Parameter name and use lower case on the remainder -that’s a rule is used universally in Revit and it simplifies making Parameters. Another thing is that once you’ve changed the size and/or shape of a Fill Region, you need to run the rule again. I know that’s not ideal but it is something which is a limitation of the Revit API i.e. the way that Autodesk allows developers to access the Revit Project Database is deliberately limited in some ways. If we have calculated parameters running constantly, our projects might grind to a halt!

If you have Revit.XT and you haven’t played around with it, I invite you to have a look at it – you might find it very useful.