Object Oriented CAD

One of the defining features of Revit (and I would assume many other BIM softwares) is that it constructs the project out of a series of individually considered and attributed objects, rather than as a series of simple geometric lines and planes.  For those familiar with AutoCAD blocks, it is as if the entire project were created entirely of dynamic blocks.

What's so special about that?

It the object oriented approach, the objects are themselves subsets of data, or information containers.  In  OOCAD one can imagine the object properties available in an AutoCAD object such as a line containing more information than its geometric and formatting options.  What is both important and powerful about this approach is that it becomes possible to register and eventually understand a project as more than its geometry.  As well, changes to the types can be used to update large numbers of object instances throughout the project quickly and accurately.

A window in the project is created from the "window-variable-standard" basic object type (as seen on the top right) scaled to fit its opening and located in the project through the properties in the right panel.  The object types properties (center) can be used to modify the type's relative dimensions (in this case frame depth, window location etc.) as well as model, manufacturer and cost information.

As well, performance information about individual materials and assemblies can be registered within the 3 dimensional model.  The model can be useful to multiple members of the project team,

Properties for a wall type include: (middle) the various layers of an assembly, their function within the assembly and the way in which they turn corners;  each of those layers is also given its own material properties (left) including a graphic appearance and engineering details.

Programming specialists will likely point out that most CAD platforms already are object oriented in their programming construction, but what I mean by this is an approach to constructing building elements out of information rich and multiple smaller pieces, which already are in tune with the expected industry product types and standards, that are then transformed to create the individual building.  This amounts in my mind to an actual break from past CAD methods which were largely drafting table operations performed on a piece of software. On a drafting table, it is not possible to create the types of information rich objects that can be done with OOCAD;  this was done instead through the system of typical project documentation of drawings, annotation and specifications.