14S |June/July2010 G oogle SketchUp (SU) is an excellent program for system designers to keep in their digi- tal tool bag. Perhaps its greatest attri- butes are that it is available in a free version (sketchup.goo gle.com) and that it works in conjunction with Google Earth (earth.google.com). Tis means that every roof shown in Google Earth can be converted into the plan viewfor a potential solar installation site or used to add detail to a 3-D model. SU software can also transform 2-D DWG and DXF les created in CAD software into 3-D virtual rooftops brimming with solar equipment. Te following steps detail one approach to this process. CAD preparation. Importing CAD les is possible with Google SkecthUp Pro, which is available for $495, or with the 8-hour evaluation version. When pre- paring CAD images to import into SU, remove unnecessary plan details and text, and ensure the units of measure are correct. (See Figure 1.) A simplied plan view of the installation site serves as a foundation on which to build the 3-D model. Make sure to retain anystructural features that limit the arraysize or inuence the project scope. Import and scale. In SU’s File menu, chooseImportto open the prepared CAD le. After the image loads, verifythat it is scaled correctly. (See Figure 2.) Select the ape Measure tool, then click on the end points of any line in the model for which the actual, exist- ing length is known. Measurements are displayed at the bottom-right corner in the SU window. If the image is not to scale, simply enter the cor- rect length, including units, and press Return. A length of 10 feet 3 inches, for example, requires an input of 10´ 3˝, 10.25´ or 123˝. Use m, cm, and mm for metric units. o i d o p g 16 Figure 1 This simplied plan view is ready to import into SketchUp. o u r t e s y s e p a r t n e r s . c o m ( 2 ) Figure 2 After the simplied plan view is imported, verify the image scale. Q A Qualty ssurance Create 3-D Models in Google SketchUp Using CAD Files
