ADT-AEC Editing TUTORIAL
Why EDIT ADT's AEC Content?

There is a lot of discussion as to the relevance of "clean" modeling, due to the increased computing power and fast ray tracing non-mesh based GI rendering engines. Relevant workflow duration (time!) drive the discussion. Driven by this demand, programs such as Architectural Desktop (ADT), utilize "AEC Content". Parametric Content streamlined for CAD Drafting & suitable for 3D Design. Notice the word: "suitable"; meaning it "can be used". It is not "ideally" orientated for 3D.

ADT & 3D Problems
AEC Content Difficulties

All the difficulties generally summed up as vertices generation and placement. Efficient & Clean 3D modeling is at its roots perceptual, that is to say variable and view dependant. ADT's 3D Mesh / surface generation of AEC content needs to be very efficient. The real purpose is for generating construction documents of very large magnitudes, with reasonable 3D capabilities (visual aids). At times, the vertices & thus, surfaces are at odds with how the modeled objects should look.

Modeling By ADT Profile
Changing the AEC Profile Shape

ADT uses a predefined solution for the windows and doors. When the profile shape is square, they work just fine, (except the possibility of thin long faces). A profile that includes an arc is different. The predefined solution uses a deviation-based definition of the edges and vertices. Essentially, Geometrically defines an arc by maximum chord length & division of arc segment. The Quarter round window as an example; a 2'x 2' has three sides, a 5'x 5' has 6 and an 8' x 8' has seven sides, representing the arc. Great for keeping CAD file sizes down, not always acceptable for visualization purposes.

To overcome this one needs to replace the predefined solution with an AEC profile (Special definition of Closed Polyline). With a standard mesh based surface curves do not exist, such as brezier splines and nurms surfaces. There are two ways to set up the polyline, all "line" or "line" and "arc".
An all line uses "line" segments for the shape. More segments and in particular more lines that represent the arc segment, the smoother the arc will appear.
Lines for the right angles and "arcs" for the round segments. The polyline "arcs" behave just like the predefined shapes. There is a catch, multiple polyline "arcs" tend to fix the segments. One arc equals two segments verses a single or half polyline arc defining the round, scales similar to the predefined shapes.



Creating a new window profile using an all "line" polyline.
• Create; Create 3 layers with different color assignments for: reference circle, division lines & polyline profile.
• Open the drafting settings (r-click OSNAP button>settings>snap & grid tab). Check; Endpoint, Midpoint, Center, Intersection & Apparent intersection.
• Draw a circle (center at 0,0,0 optional), the radius is not critical, on the circle reference layer.
• Change current layer to division line & Draw a polyline, start by snapping to the center of the circle. End the polyline outside of the circle.
• Select the new polyline, click on the array button (type array in the cmd line). Set to polar array, array center is the reference circle center. Method is up to you but the values should be; Total number of items-24, Angle to fill-360, angle between items 15.

• Preview the array, making sure the values and settings are correct and click ok or make changes.
• Make the profile layer current. Start a polyline at an "intersection" (OSNAP) of a division line and the reference circle. The default polyline type is "line" so continue adding line segments from division line intersection to division line intersection of the reference circle.
• At the last segment, right click and select close.
• Select the new profile poly line, you may need to cycle select (Ctrl & select), and move it away from the reference shape.

Creating a new window profile using an all "arc" polyline

• Start a new polyline like before. Once the starting point is set, right click and select "arc".
• Move to a point of intersection 180 degrees (circumference) and click to set the next vertex / line point. You may also use the polyline "center" mode to define the arc (in arc mode r-click>CEnter>define center pt>define arc length / degrees). The method used helps illustrate the flexibility of shape creation.
• Continue with the arc type poly and divide the second half by 60 degree segments.
• Close the polyline.
• Adjust the vertices using the intersection OSNAP function. Select the polyline, select an arc midpoint and drag to an intersection (or: apparent intersection, extension). The arc mid point needs to

Creating A New Window Style

Defining a polyline as a profile

• Open the profile definitions Desktop>Profiles>Profile Definitions. This displays a filtered view of the entire Styles manager.
• Right click over the "profile definitions", top of tree. Select new from the menu.
• A new profile definition is then highlighted in the sub-tree. Rename this to Rparc (Round Polyline arc).
• Hover over the Rparc profile, right click, and select "Set From". The dialog box is now hidden; select the polyline made from all arcs.

• Repeat the previous steps for the all "line" polyline and name it Rpline.

You can see in the viewer windows the new shapes, interpreted and displayed. Zoom in and out on the Rparc profile. Funky differences from 180-degree single arc compared to the 3-arc side. Note that the 3-arc side, when in a 3d window style, may have less divisions, but the vertices are in line through the window components.

Create the new window styles



• Open the style manager, Desktop>Style Manager. Scroll down and select window styles.
• Right click on any window style and select new. Do this twice. Name one new style Rparc and the other Rpline.
• Hover over Rparc and right click. Select Edit from the menu. In the Window styles properties box select the Display Tab.
• Select the Custom Radio Button. Then from the drop down list, select the Rparc profile style just created. Repeat for the Rpline Window Style and use the Rpline profile style as the custom shape.
• Using the viewer makes sure the profile and such is correct. Now is a good time to alter the display properties. The method described in earlier tutorial. I generally use red for the frame, yellow for the stop and green for the glass, if importing into Viz or Max.

Create a wall and put the new window styles in. See how they render out. Try some different shapes and sizes.

Parting Thoughts
ADT Modeling Control

As you can see, there is quite a bit of control over how the modeled AEC Design Content. Round or arc windows present some difficulties when face modeling. Here is a way to set up vertices to snap to, when face modeling. The ADT window model is fine, as created, if the arc segments suit your needs. Overall the Only drawbacks are the number of coplanar faces, if an issue & wall tessellation.

This can dramatically increase the number of faces in ADT. Windows and of course the walls that the windows are in. Not good for use as the CAD application & creating construction documents. It would be advisable to duplicate and rename the file before making these types of modifications.

The next tutorial will look further into CAD Modeling for 3D Applications