The 'Not Making Drawings' CAD Program

BOA Research loves to describe BOA as a CAD program which eliminates drafting. While this is an admirable goal, the truth is more like this: instead of making drawings you spend a portion of the time it would take making drawings making the "virtual building" model. Once the model is made you do get much of what is in the drawing for free, minus the necessary annotation elements (notes, callouts, symbols, et cetera). That brings us to some key questions.

This is clearly the more fascinating aspect of model-based CAD programs. Like ArchiCAD and Revit, to name a few examples, BOA makes drawings by slicing through the building horizontally for plans and vertically for sections. For elevations, including interior elevations, you view the model from the side flat on.

In comparison to other model-based CAD programs, BOA presents cut views in a unique way: it is the elements there and then being shown in the cut view. You can directly manipulate them. In other programs these sliced model views are often translated 3D data to 2D data, you are not actually looking at the 3D data anymore, but a "representation" that is tied to it. With BOA it's the real 3D stuff all the time. And in BOA Research's opinion, this makes the program technically more "robust".

To make these slices you move the workplane to a particular point in the model, save that position, and set up a series of "drawing planes" using the Cut Plane palette in the Utilities menu. Drawing planes are parallel to the workplane and you can have multiple planes associated with a particular drawing. Essentially each drawing plane and the space between them acts as a spatial region in which any element found (visible in it) can be defined to be viewed with particular delineation values (line thickness, color, line type, pat fill, etc.). These attributes of blocks viewed via a drawing setup can override the true colors and line attributes of the model data, hence you can set items to be compatible with Autocad line colors, for instance. You may have noticed for instance that in BOA we ran with the program's default purple (for blocks) and green (for workplane cut) combination—which you always override with any colors you like. But in viewing the next image below, the colors are set to Autocad pen colors. (see below).

Drawing to Model Coordination

The big question that most folks may wonder about is the total amount of time needed to make the model and then set up the drawings. Is it really faster than just making the drawings? This is a really good question. Two things will shape this answer. First is how fast you are at modeling elements in BOA. The second is how adept you are at working with workplanes, setting up drawings using the Drawing Manager and the Cut Delineation tools.

Learning how to model a virtual building in BOA is pretty straight forward so long as the building itself is pretty straight forward. Nader is very fond of reminding folks that most architecture is rectilinear...and not shaped like some Frank Gehry project. That being true, if your work is quite normal this way, BOA can be a powerful and quick modeling tool. If your work is much more complicated, you may run into more difficult or at least 'time consuming' modeling chores.

On the second aspect, setting up drawings can be incredibly quick once you truly master the program. And even if you don't master it quickly, setting up drawings is not as time consuming as you may think. But we'll let you be more of the judge of that when we deal with that almost exclusively in the second Indepth Article on BOA in July.

In the view below you can see one drawing to the left and its data in 3D to the right. Yes, if you think you are looking at annotations in axo that is correct. BOA has the ability to view 2D text in perspective or axo. Notice the green lines cutting through the wall blocks. That is the workplane location.

The biggest advantage BOA may have over a traditional drawing-centric CAD program is dealing with design changes which are made after the drawings are created. With BOA drawings and virtual-model data have two-way association. Changes in one are reflected in the other. Change a wall position in the model data, and every drawing where that wall (block) is presented will reflect that change. While traditional CAD programs try to deal with this with shared layers, view-ports, and symbols, all these systems have serious limitations compared to a model-based CAD system.

Finer Points

As we touched on, BOA is compatible with Autocad through an import/export translation process. For quick tasks related to Autocad sharing, BOA allows you to setup a drawing without the two-way drawing-to-model association, thus expediting this process a bit.

BOA is an OpenGL CAD application and its implementation is solid. We noticed only a few final hidden line anomalies when it came to the edges of certain planes. BOA 2.4 is also a very solid application. It never crashed during any part of the review. The overall speed of working with a virtual model of a building with complete annotation in 3D (made possible via Apple GX Graphics) was fairly decent. We would be stretching the truth if we said it was rather fast compared to other OpenGL apps on Macintosh; however with small files -- like the tutorial tower, it was plenty darn fast on a 350MHz G4 tower and even faster on a 500Mhz Titanium PowerBook G4.

BOA's killer feature is its use of the Workplane. One of the coolest things you can do with it is step through your building in section, even in perspective! This affords in interesting way to present your project. It would nice to see this process automated a bit for an OpenGL-rendered QuickTime presentation. BOA itself is not really geared for presentation quality architectural rendering, and lacks sophisticated rendering tools. Instead, BOA provides a way to export your model data into other rendering programs, like FormZ, Art-lantis, Strata or any higher end program with DXF import.

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