My interest is in the use of software for use by architects and designers. I always start any training class with definitions.
What is CAD?
CAD is a generic term that means “Computer Aided Design” and is used to indicate a class of software that is used to create dimensionally accurate drawings. You may also see it spelled CADD which stands for “Computer Aided Design and Drafting” there is no difference between the class of software these two terms refer to. Sometimes you may see references to CAD/CAM. CAM is Computer Aided Manufacturing. Although all CAD programs have many things in common, CAD/CAM programs are specifically intended to design and manufacture products and aren’t typically used for architecture. Any CAD program can be used to draw architectural construction documents.
Who is Autodesk?
Autodesk, Inc. is a software company based in Sausalito, California. Autodesk develops and markets a variety of software programs. Autodesk owns, develops and markets several graphics software programs. The three CAD programs they have of most interest to architects are AutoCAD, AutoCAD Architecture, AutoCAD LT, and Revit.
What is AutoCAD?
AutoCAD is the name of a CAD program first introduced in 1982. It is a general purpose CAD program, and was the first CAD program that would run on a Personal Computer. Most architects in the United States use AutoCAD.
What is AutoCAD Architecture?
AutoCAD Architecture is AutoCAD with additional architectural design and drafting tools. Many architects use this. It provides many features that can save time in producing architectural drawings.
What is AutoCAD LT?
AutoCAD LT is the name of another CAD program. It is sometimes referred to as AutoCAD Light, although its name actually is AutoCAD LT. It is basically AutoCAD with some functionality removed. Most notably it lacks some 3D modeling and custom programming capabilities that are included in AutoCAD. This is an excellent alternative to AutoCAD for those architects that don’t need 3D modeling capabilities and have no need for custom commands and menus.
Are there other CAD software programs?
Yes. There are many. Here is a link to a list of general Purpose 2D and 3D CAD Programs
What is BIM ?
BIM does not mean 3D, but it does typically use 3D dynamic building modeling.
BIM is sometimes used to refer to parametric objects, but that is a sloppy definition.
BIM is often used to mean Revit, but that’s not correct. Revit was not even the first BIM software product. Autodesk adopted BIM as a marketing term and it has caught on. It was intended to separate Revit from its competitors, but now they all use it. Revit is so much different from AutoCAD or ADT that many people that use Revit refer to it as BIM and to everything else as CAD.
BIM stands for “Building Information Modeling”. It is the process of generating and managing building data during its life cycle.
Are there other BIM software programs?
Yes. The most popular are;
ArhiCAD (Graphisoft) – arguably the first BIM software program.
Microstation or Bentley Architecture (Bently)
Vectorworks Architect (Nemetschek)
Architectural Desktop (Autodesk) – This is the previous name for AutoCAD Architecture – many don’t realize that this was also marketed as a BIM program.
What is Revit?
Revit is a parametric building modeler for architects and building design professionals. It was built from the ground up as a tool architects, and it shows. Revit is a CAD program. And, yes, it is also a BIM program.
How does Revit compare to AutoCAD.
Some of the biggest changes (and improvements) are things Revit does not have.
Some things Revit does not have;
|user coordinate system (UCS)||Colors|
|Plot routines||Color dependant plot style files|
|Command Line||Cursor crosshairs|
What are the basics of Revit?
There are 2 kinds of objects in Revit; 3D objects and 2D objects.
You place and modify 3D objects to build a virtual 3D model of your building.
In the set of sheets typically needed for a building project, there may be some 3D views, but each sheet will primarily contain one or more 2D drawings. In Revit, each of these separate drawings is a different view of the same 3D model of the building. These “project views” of the model make up the plans, reflected ceiling plans, sections, elevations, and details. One of the very clever things that the makers of Revit did was to let you work in these 2D views to create the 3D model. You will be working in 2D most of the time, even when drawing 3D objects. 2D entities are used to “finish” these 2D views by adding things like dimensions, crosshatch, or 2D lines to show more detail. These 2D entities will only show up on the 2D view they are drawn in.
Different types of entities behave in different ways. Take walls for example. Doors and windows can only be placed in walls. If you create a 3D shape (sloped, curved, basically anything you can think of) and call it a wall, you can then place a door or window in it. You can create your building using more or less “standard” construction techniques. Or, you can go completely crazy and create any shape you want. If you call it a wall, it will behave like a wall. The same is true for all of the other entity types; floors, ceilings, slabs, roofs, columns, etc. Revit typically provides you with a set of generic entities to use, and tools to place or draw them in 3D. You can copy or modify these, or create your own.
For each type of 3D object, such as a wall or a door for instance, you can define what you want it to look line in a 3D view or projected onto a 2D view (like an elevation). You can also define what it looks like when cut in plan or section. (Plan views can look different from section views.) You can also define, for each of these views, what it will look like in a “coarse”, “medium”, or “fine” level of detail which allows for a different amount of detail at different scales.