AEC from the Ground Up--Preliminary Design Tools1 Jul, 2006 By: AIA ,H. Edward Goldberg
Productivity in AEC begins with effective digital tools
Preliminary design tools in the AEC arena fit into a niche that is quite different than that for 2D CAD or BIM (building information modeling) tools. Although CAD and BIM applications create accurate construction documents, they are always vector based and generally aren't conducive to design. Preliminary design tools, on the other hand, tend to be more responsive to quick or natural input. Among the 3D preliminary design tools are Autodesk's VIZ, 3ds max and Maya; Google SketchUp; Cinema 4D; Form•Z and Rhino. Although these programs are vector based, they are optimized to create and render 3D models quickly.
2D drawing programs usually are bit-mapped solutions such as Autodesk Sketch Book Pro and Adobe Photoshop. These bit-mapped solutions can mimic actual hand strokes. Using a light pen or Wacom resistive tablet such as those used on tablet PCs, users truly can replace paper and pen and create real 2D hand-drawn digital records.
As the AEC industry moves into the BIM or virtual model world, 3D becomes more important. Many designers are adept at using 3D preliminary design tools, but others prefer to draw in 2D and then transfer their designs to a BIM program such as Architectural Desktop, Revit or ArchiCAD.
To achieve greatest productivity, the preliminary design and documentation tools should be integrated digitally. This process is easy for the 3D vector-based solutions, but not so for the 2D drawing programs. The problem for the bit-mapped programs is the conversion from hand-drawn 2D to 3D model. Here a raster-to-vector conversion program can help. I discuss two here, but many others are available from vendors such as Rasterex, GTX, softelec, MagicTracer and Autodesk.
The next step beyond that is converting the vector lines to architectural objects, a chore handled nicely by programs from Consistent Software.
Depending on your preferred design method, the preliminary design tools I discuss below can make your job quicker, easier, and more enjoyable. I look forward to the day when some developer creates a total solution that will allow us to go instantaneously from a hand-drawn 2D digital sketch to a building model.
Figure 1. The Wacom Cintiq lets users digitally draw as if they were using pencil and paper.
• Adobe Photoshop
• Autodesk Sketch Book Pro 2
• Wacom Cintiq
If you want to draw with pencil and paper but still be digital, the Wacom Cintiq (figure 1) or a tablet PC combined with Autodesk Sketch Book Pro or PhotoShop is the way to go. The Cintiq is a flat-screen monitor combined with a resistive digitizer tablet identical to the smaller screens available with tablet PCs. The 20.5" Cintiq is available for $2,500. The stylus that comes with the Cintiq is pressure sensitive, wireless and battery-free. If you want to sketch digitally in the field, a tablet PC and Autodesk Sketch Book Pro is as close to drawing with pencil and paper as you can get. Autodesk Sketch Book Pro 2 ($179) is a raster drawing program available for PCs and Macs (figure 2). It uses raster brush technology gleaned from Autodesk's high-end industrial design software, originally developed by Alias. Sketch Book Pro 2 features a gesture-based user interface built around a patented Marking Menu technology. Adobe Photoshop is a higher-end raster program that does everything Sketch Book Pro can do and a whole lot more, but has a higher price tag.
Figure 2. Autodesk Sketch Book Pro 2 features a gesture- based user interface built around patented Marking Menu technology.
• Softcover International
Scan2CAD is a raster-to-vector converter that automatically converts scanned drawings or freehand raster sketches of floor plans created on tablet PCs into DXF files that can then be imported into just about any PC-based CAD program. Depending on the care with which the sketch is created, Scan2CAD's default architectural settings can, without any manual intervention, convert a JPEG, bit-map or TIFF file into a DXF file that provides a useful starting point for redrawing.
Scan2CAD's default settings can be adapted to straighten lines and corners (walls) and smooth arcs (doors). Scan2CAD includes Snap-Tidy vector editing tools to facilitate cleanup of broken vectors. These worked well on the supplied test image—conversion and cleanup took less than 5 minutes from start to finish. The Regular version ($279) opens monochrome, grayscale and color images and converts them into black-and-white DXF. The Pro version ($469) saves color DXF files. It's more suited to professional users who want to do automatic batch conversions of large-format scanned paper drawings or OCR (optical character recognition) text recognition and training. All in all, Scan2CAD is an attractively priced solution with a practical range of tools.
• IDEAL Scanners & Systems
WiseImage Pro ($3,240) vectorizes monochrome, grayscale and color images. A unique search-and-replace utility allows users to define a raster pattern for which to search and then define which vector, text, raster object or AutoCAD block to replace it with. Users can exploit WiseImage Pro's intelligent conversion options for lines, arcs, circles, linetypes, hatch, text and blocks to customize the process. Postprocessing and cleaning up of text and vectorized object is easy with WiseImage Pro tools. Users can even change geometry from lines or polylines into arc and circles.
• Consistent Software
PlanTracer for Architectural Desktop ($980) and Plan2Model for ArchiCAD ($1,400) recognize any 2D vector file and convert the vectors automatically into Architectural Desktop 3D models or ArchiCAD 3D models (figure 3). These vector-recognition programs can be trained to recognize vector drawings much as voice recognition programs recognize the spoken word. Once trained, the software can interpret hand-drawn cryptic marks that indicate doors, toilets and kitchen appliances. Neither Plan Tracer nor Plan2Model converts rasters to vectors, so you also need a raster-to-vector converter if you're starting with raster drawings.
Figure 3. PlanTracer ADT coupled with a raster-to-vector conversion program will easily convert bit-map drawings to Architectural Desktop 3D models.
• Google SketchUp 5
SketchUp is a great preliminary design tool for three reasons:
- 1. It's relatively easy to use and very capable.
- 2. It has an excellent price point ($495).
- 3. Free plug-ins are available that allow users to automatically convert models created in SketchUp into Architectural Desktop, ArchiCAD, Revit and VectorWorks AEC objects such as walls, floors and roof slabs (figure 4).
Figure 4. Free plug-ins convert SketchUp models to Architectural Desktop, ArchiCAD, Revit and VectorWorks models.
Through its exports—DWG and 3DS—SketchUp models can be exported into most CAD programs for further manipulation and documentation. SketchUp 3D models also can be brought into Autodesk Revit where walls, slabs and so forth can be assigned to them.
SketchUp is available for both PC and Macintosh. Thousands of designers depend on this software for residential and large commercial projects. SketchUp includes a free downloadable reader so clients can interactively explore (but not change) models.
NEW AEC FORUM
Autodesk has beefed up the 3D design tools and rendering capability in its new AutoCAD 2007-based programs, which include AutoCAD, Architectural Desktop 2007 and Building Systems 2007. Although its conceptual modeling is not quite as subtle as SketchUp's, AutoCAD's 3D tools are quite good, and its capability to rapidly create intricate AEC models is excellent (figure 5). Architectural Desktop and Building Systems get an added productivity boost by integrating the 3D design modeling capability with intelligent AEC objects through Architectural Desktop's new massing-model-to-AEC-object capability. The updated rendering engine with new conceptual and realistic renderers allows real-time shadowing and textures (materials). Sadly, real-time shadows work only with a few approved video cards. (I will analyze the approved NVIDIA video cards in an upcoming Cadalyst Daily newsletter).
Figure 5. Autodesk improved the 3D design tools and rendering capability in its new AutoCAD 2007–based programs.
New presentation tool. Autodesk is developing a new application, called Impression (figure 6), for creating presentation graphics. The initial release will bridge the presentation gap between CAD drawings and full-blown photorealistically rendered presentations. Impression will read DWG and DWF CAD files and understand blocks and layers. Prebuilt styles and content will help users create design presentations. Look for Impression to appear this fall.
Figure 6. Autodesk s upcoming Impression product will helpusers turn CAD drawings into design presentations.
Autodesk's Revit platform—Building, Structure and the new Systems—has an excellent built-in preliminary design modeling tool that is very capable with organic shapes (figure 7). Users can assign intelligent AEC objects such as walls, roof, slabs and curtain walls to virtual massing models.
Figure 7. Autodesk s Revit platform has an excellent built-in preliminary design modeling tool, which is great for organic shapes.
Graphisoft's ArchiCAD 10 provides greater modeling freedom and, with the help of MaxonForm, lets architects develop organic shapes that are fun to produce (figure 8). MaxonForm is a customized version of Maxon's Cinema 4D that creates freeform and organic shapes with more powerful modeling tools than ArchiCAD's own toolset for GDL (geometric description language) editing. The suggested workflow is to start the basic building in ArchiCAD and, with one click, bring the ArchiCAD model into the MaxonForm modeler to use its freeform tools to create forms such as rounded roofs and wildly deformed shapes within the context of the building structure. The floor plan representation automatically is the correct horizontal cut of the organic object, but users can create any horizontal or vertical section they wish.
Figure 8. ArchiCAD and MaxonForm, a customized version of Maxon's Cinema 4D, combine to create freeform and organic shapes. Image courtesy of Hickton Madeley Architects.
• form•Z 6
Form•Z is a CAD-centric visualization program for creating 3D study models. Developer auto•des•sys planned to release v6 in late June. New features include object animation and 3D printing with color and textures. The program adds support for Z Corp.'s ZPR file format for 3D printing as well as a 3D print preparation tool that identifies model areas that won't print properly. Other additions include skinned lofting for generating objects that branch and morphing, which changes the shape of a source object to that of a destination object by a certain percent.
This popular NURBS-based modeler ($895) from McNeel & Associates lets users create freeform models that can be exported in a variety of CAD formats, including DWG/DXF, SAT (ACIS), X_T (Parasolid), and STL.
H. Edward Goldberg, AIA, NCARB, is a practicing licensed architect and AEC industry analyst. Ed's full-length book, Autodesk Architectural Desktop 2006: A Comprehensive Tutorial (Prentice Hall; www.prenhall.com) is now available, and a 2007 version will come out this fall. Visit www.hegra.org or e-mail email@example.com
About the Author: H. Edward Goldberg
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!