When we first created it, TTX started out as our structural BIM interoperability platform. Its purpose was to bi-directionally exchange model information between our most commonly used structural analysis and modeling packages. Since we started using a database back-end, we could also keep track of each project revision: every time a project is synched to the TTX database from any of its currently supported programs—which include Revit, Grasshopper, Tekla, SAP and very soon RAM and ETABS—a new database entry is added to the TTX project. This entry contains information about the application that synched to the database, such as the sync date, user name and a user-defined message describing the latest change. It might look something like this:
• User: KMurphy
• Software: Revit 2014
• Sync Date: Dec 07, 2013, 21:15:23
• Message: Added roof to the model and modified grid lines 1 to 10
In addition to this information, we keep track of every element that was created, deleted or modified.
Project Revision History
Now, the CORE Studio team has created a revision history interface in Grasshopper, which lets the user parse the individual timestamps of the project and review what was changed, when and by whom. Using the Grasshopper interface we can also compare the stage of the project at different time intervals. We can also run custom queries on the model, such as, “Show me all the changes that we made in May.” Or: “Show me all of the changes that were made by SAP or ETABS.”
Another great byproduct is the ability to roll back all models to an earlier time period in the project.
Model BIM Queries
We also created a number of tools that allow us to run very quick queries on the model. Based on our selection of the element type and one or more conditions for a certain element attribute, the tool returns all elements where this condition is met.
For example, one could extract all elements of type Beam, where the section name contains “W14” and the rotation angle is between 90 and 180 degrees.
Model Force Queries
For all models that run through a structural analysis, we also collect member forces in the TTX database. This means that we can let the query return all member forces where, let’s say, the axial force is between 10 and 20kN. BIM and force queries can be combined this way.
The best part of developing these plugins for TTX is that our engineers constantly come up with new ways of using the platform. We imagined that it would be used for interoperability, but more and more it is being used for iterative capturing of analysis data. I am curious to see what this will lead to next.