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Originally published at AECBytes: http://www.aecbytes.com/tipsandtricks/2009/issue45-archicad.html
written by Jeff Olken
Jeff Olken ARCHVISTA Building Technologies
Over the years, I’ve helped many clients to implement BIM. One of the most common questions during the introductory sessions has been, “How do I draft as quickly in BIM as I am used to in …?” You can fill in the blank, because the question has referred to many kinds of software packages and to hand-drafting. Nonetheless, the importance of drafting quickly and easily translates to modeling quickly and easily. The fact that we model the building registers with my clients, and they have been generally optimistic about the overall process by the end of the training.
Challenging Drafting/Modeling Situations
One of the most significant criteria when discussing “drafting quickly and easily” is the ability to overcome challenging drafting situations. For example, drafting a line (or modeling a wall) of a given length is universally easy.
Connecting lines (or walls) to each other is only slightly more challenging. More significant challenges occur when:
∗ Trying to align walls (or lines) with other elements in the model while in the middle of a command.
∗ Attempting to create a fill (hatch) that has a consistent 1’ offset from the surrounding walls in a room.
∗ Placing a light in the center of a room; centering a window between other elements on a wall; or moving a set of objects based on the center of the group when there is nothing placed at that center.
The typical solution to all three of these challenging drafting/modeling situations is to create construction lines, and then model based on the construction lines. Then, once the modeling/drafting is complete, simply delete the construction lines. Hmm, “Simply delete them?” Why draw construction lines in the first place? And is it always simple to delete the construction lines? There is a lot of room for error when using construction line work—often one deletes items that are necessary, or leaves lines that don’t belong in the drawing.
Our solution: unlock the hidden drafting/modeling controls within ArchiCAD and learn to use them.
Modifying the Work Environment
In ArchiCAD, the interface look and feel is controlled by the Work Environment settings. These settings are individually customizable, and are stored on the work station. The interface is independent of the project file, and is highly flexible. By default, ArchiCAD ships with three “profiles.” The most commonly used profile is called Standard, and presents a clean, intuitive interface which is great when first learning the software.
As you use ArchiCAD more and more, and become comfortable with the Standard Profile interface, you’ll probably find that you’d like to move parts of the interface to suit your working style more comfortably. With ArchiCAD’s flexible interface, it’s not a problem—work the way you’d like without hesitation or constraint. Hidden from view, by default, are two “palettes” which contain drafting commands that can help overcome challenging conditions. Access these two palettes by activating them from the Window > Palettes menu tree. The Coordinates and Control Box palettes provide access to useful information and powerful commands in a convenient interface.
Once you’ve activated these two palettes, the next question is, “Where do they go?” We prefer them at the bottom of the screen, where they are easily accessible while working, yet minimally impacting the modeling workspace. On Windows, they will dock like a Toolbar, while on the Mac, they’ll snap into place like any other palette.
Let’s now look at some of the commands in the Control Box as we address how to breeze through drafting situations that would normally require construction lines.
Using the Control Box
The Control Box consolidates powerful, on-the-fly, drafting commands. When in compact form, which is the default, the commands are grouped by type in a single button. When expanded, each command is displayed individually. If you have enough screen space, and feel comfortable looking at twenty-four individual buttons, then the expanded mode is for you. Otherwise, use the compact mode. Right-click any button to activate the context menu.
The most important command groups are Guide Linecontrols, Construction Methods, Align Direction and Snap Points Let’s take a look at how to apply each of these command groups while we solve our drafting challenges.
Challenge One: Align a Wall to a Point while Drafting/Modeling
When creating a wall, we have easy control of its start point, its length, and its direction. But what happens when the wall is angled, and needs to end based on an already existing item, but without actually touching that item? In ArchiCAD, we leverage the Align Direction tools, also known asCursor Snap Variants.
Snap variants become active when you are constraining the drawing vector by holding down the Shift key or locking the Angle. To draw the pony wall, we hold down the Shift key, or type Alt/Option-A to lock the angle. Once the angle is locked using either method, simply click on the appropriate Align Direction and click on the reference element.
Challenge Two: Center Window between Door and Corner
While this is not a horrendously tough challenge, we still would like to be able to place the window without a construction line. Another set of commands in the Control Box are collectively called Relative Construction Methods.
These commands constrain an element to be drawn relative to existing elements, along a Parallel, Perpendicular, and Angle Bisector. Thanks to guidelines, introduced a few years ago, these first three commands are rarely needed. However, the next three commands are quite useful, and can only be accessed from the Control Box. They are Offset, Multiple Offset, and Special Point Constraint. We’ll look at Offset shortly, but to tackle this challenge, we’ll use the Special Point Constraint. This command uses the setting of the Special Snap Points to combine a construction line and click when placing elements like windows, lights, etc. Additionally, it can be used to set a reference point for dragging a group of elements based on their center, without creating lasting line work.
To use this command, follow these steps:
- ∗1. Set Special Snap to the appropriate value.
- ∗2. Select the tool or command (like Drag) to be used. In this case, we’ll use the Window tool and set the placement point to “center.
- ∗3. Click the Special Point Constraint button, or choose it from the fly-out menu
- ∗4. Click the first reference point. In this case, we’ll click the door frame. Note the dot on the leader line. That will be the window’s insertion point.
- ∗5. Click the second reference point. As the window is to be centered on the wall, we’ll click the inside corner of the room.
The window has been inserted based on the half point of the temporary construction line. This method can be used in limitless applications, like placing an object at the center of a room by referencing diagonal corners.
Challenge Three: Placing a Fill at a One Foot Offset from the Walls
We have time for one last, really easy challenge. By activating the Control Box, we have given ourselves access to the Offset command. In this case, we need to make sure we understand the power and flexibility of ArchiCAD’s offset. When offsetting, we can create any new element, based on the existing geometry of the project. We can trace any path, reference any shape, and even automatically trace an enclosed space like a room. There are four steps to creating a new element using the Offset command:
- ∗1. Activate the tool and set the attributes of the element to be created. In this case, we’re creating a tile fill, so we’ll activate and set the Fill tool appropriately, including the geometry method.
∗2. Click the Offset (or Multiple Offset) button.
∗3. Trace the path to be offset. You can use the Magic Wand tool to automatically trace a continuous path, or find an enclosed space.
∗4. Set the distance and direction of the offset. Repeat when using Multiple Offset.
That’s it—we have, very quickly, created a tile pattern with a 1’ border offset from the edge of the room.
I hope you will find this added drafting power useful. The Control Box and the Coordinates palette can greatly enhance your efficiency and flexibility when working in ArchiCAD. To make them a permanent fixture in your workspace, create a new Work Environment after adding them. If you’re interested in furthering your knowledge on this topic, we offer a series of six recorded classes focused on ArchiCAD How to… as part of your LearnVirtual membership, plus over 110 recorded classes and weekly LIVE eClasses on a range of topics including modeling techniques, drafting techniques, process management, revision management, rendering and animation. To learn more about LearnVirtual , go to www.learnvirtual.com.