Copyright Goodheart-Willcox Co., Inc. Chapter 13 Text and Dimensions in 3D 335 Creating a 3D Dimensioning Template Drawing If you often create dimensioned 3D drawings, make a template drawing containing a few 3D settings. Starting a drawing based on a template will speed up the dimen- sioning process because the settings will already be made for you. • Create named dimension styles with appropriate text heights. See AutoCAD and Its Applications—Basics for detailed information on dimensioning and dimension styles. • Establish several named user coordinate systems that match the planes on which dimensions will be placed. • If the preset isometric viewpoints will not serve your needs, establish and save several 3D viewpoints that can be used for different objects. These viewpoints will allow you to select the display that is best for reading dimensions. • If 3D dimensioned views are to be used with a multiview 2D drawing, create a paper space drawing layout containing appropriate viewports and the required items listed above. NOTE NOTE Multiview orthographic and pictorial drawing layouts can be created quickly and effi - ciently using the VIEWBASE command. Creating drawing views from 3D models is discussed in Chapter 14. Placing Dimensions in the Proper Plane The location of dimensions and the plane on which they are placed are often a matter of choice. For example, Figure 13-7 shows several options for placing a thickness dimen- sion on an object. All of these are correct. However, several of the options can be eliminated when other dimensions are added. This illustrates the importance of planning. The key to good dimensioning in 3D is to avoid overlapping dimension and exten- sion lines in different planes. A freehand sketch can help you plan this. As you lay out the 3D sketch, try to group information items together. Dimensions, notes, and item tags should be grouped so that they are easy to read and understand. This technique is called information grouping. Figure 13-8A shows the object from Figure 13-7 fully dimensioned using the aligned technique. Notice that the location dimension for the hole is placed on the top surface. This avoids dimensioning to hidden points. Figure 13-8B shows the same object dimensioned using the unilateral technique. Figure 13-7. A thickness dimension can be located in many different places. All locations shown here are acceptable.