Copyright Goodheart-Willcox Co., Inc. 388 AutoCAD and Its Applications—Advanced resulting shaded display, the outer portion of the ring-shaped bend is shaded green. This indicates an area of maximum curvature. The recessed surface is shaded blue. This indicates an area of minimum curvature. To turn off the curvature analysis display, use the ANALYSISCURVATURE command. Select the Turn off option. You can also pick the Clear Curvature Analysis button in the Analysis Options dialog box. Draft Analysis When designing a part that will be removed from a mold, a draft angle is designed on the part to ensure that the part can be pulled from the mold. Draft analysis is used to evaluate a solid or surface model for adequate draft. In AutoCAD, draft analysis is performed with the ANALYSISDRAFT command. The procedure is similar to that used with surface curvature analysis. When you select a model to analyze, AutoCAD maps a color gradient to indicate the angle variation of the model. Green colors are mapped to areas where the draft is at the highest angle specifi ed, and blue colors are mapped to areas where the draft is at the lowest angle specifi ed. When using the ANALYSISDRAFT command, the high and low draft angles are specifi ed in the Draft Angle tab of the Analysis Options dialog box. Use the ANALYSISOPTIONS command to open this dialog box, as previously discussed. Then, in the Draft Angle tab, use the Angle: text boxes to specify the highest and lowest draft angles allowed in the model. The default values are 3.0 and –3.0. To select a model to analyze, pick the Select objects to analyze button in the Draft Angle tab if the Analysis Options dialog box is open. Otherwise, use the ANALYSISDRAFT command. Before using this command, make sure that a 3D visual style is set current. Once you initiate the command, select the model and press [Enter]. In Figure 14-50, a computer mouse is analyzed for adequate draft. The model was created as a mesh, converted to a surface, and then converted to a solid. Draft analysis is used to determine if a 4° draft angle can be used for the mold. The model after using the ANALYSISDRAFT command is shown in Figure 14-50B. The top of the model is shaded green and is within the parameters. However, there are two areas of concern along the side and bottom (where surfaces are shaded blue). This indicates that changes to the design are in order. To turn off the draft analysis display, use the ANALYSISDRAFT command. Select the Turn off option. You can also pick the Clear Draft Angle Analysis button in the Analysis Options dialog box. ANALYSISDRAFT Ribbon Surface Analysis Analysis Draft Type ANALYSISDRAFT A B Minimum curvature (surface shaded blue) Maximum curvature (surface shaded green) Figure 14-49. Surface curvature analysis. A—The original loft surface. B—The Min radius option is used to analyze the features at the end of the model. The outer “ring” is shaded green. This indicates an area of maximum curvature. The inner recessed surface is shaded blue. This indicates an area of minimum curvature.