Hybrid Digital/Manual Site Drawings
One approach to drawing a site development in 3D is to first plot the DTM in a grid pattern onto a sheet of Mylar and then draw trees and buildings by hand. Portions of the underlay drawing may be erased to avoid conflicting with the fine detail of the drawing. However, with high-altitude views, it may be difficult to understand the terrain beneath the trees.
The perspective view of Gunnison, Colorado began as a map file given to a planning team by city staff. The file was brought into AutoCAD and adjusted in perspective view. The image was saved and printed at 11 x 17" (A3) on an office color printer. Several different growth scenario drawings were created on trace overlays with a permanent ink pen and Chartpak AD markers. Each overlay was then spray-mounted directly onto a base map and color-copied for the client presentation.
Composite models can be built from site and building models. The conceptual site model shown was developed in an early site planning workshop for a new campus. The topographic information was created as a digital terrain model, and the crude buildings were formed by assigning "Z" elevations to simple shapes.
The same model, viewed from a low angle, was used to generate quick study drawings for the campus buildings. The drawings were created with pencil on vellum and colored on the reverse side with Chartpak AD markers.
The aerial perspective was created from an aerial photograph of the site that was scanned and enlarged with Photoshop and plotted at 24 x 40" (approximately A1 size). The image was constructed in red pencil and finally traced in ink onto Mylar.
You can also generate an aerial perspective by modifying a site plan using a computer. With this method, you scan the site plan and save it as a digital file. Then import it into Photoshop, select the image area, and modify it using the transform and perspective tools. This is a rapid method of changing a site plan into a perspective. You can also photograph the plotted site plan from an angle.
Another effective technique is to create a composite photograph and computer image. Photograph a street-level view, then scan and enlarge it. Next, model a proposed building and project it at the same perspective view as the photograph. Then size both images to match and use them each as a base for the final hand drawing.
A variation on this is to merge a realistic computer model with a site photo. In the example shown, the city approval process for a maintenance facility required a photorealistic computer model of the proposed building. Site photographs were taken, and an AutoCAD model was rendered and assembled with the photograph in 3D Studio VIZ. Additional trees were inserted into the site with Photoshop. An 11 x 17" (A3) color plot was presented to the client.
Computer Drawing Versus Hand Drawing
Sophisticated computer equipment makes it possible for a skilled technician to present fully animated "walkthroughs" within 24 hours. Computer renderings and animations can be extremely useful in communicating dynamic site characteristics and building design ideas.
On the other hand, drawings made with nothing more than pens, markers, and tracing paper can have equal success in communicating design ideas.
Whether you create drawings by hand or by computer is a matter of available time, your computer skill or drawing ability, access to equipment and materials, and common sense in selecting what will best communicate your ideas. If you can operate in both worlds, you'll be far ahead of the crowd.
Jim Leggitt, AIA, is a senior associate with RNL Design. He is an architect, urban planner, and professional illustrator who has been practicing in Denver for over 25 years. He teaches drawing workshops to professionals throughout the United States.
This article is excerpted from Drawing Shortcuts: Developing Quick Drawing Skills Using Today's Technology, copyright © 2002, available from John Wiley & Sons and from Amazon.com.
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