Copyright Goodheart-Willcox Co., Inc. 74 AutoCAD and Its Applications—Advanced The speed at which you walk through or around the model is controlled by the Walk speed: slider. The value can also be changed by typing in the text box at the right- hand end of the slider. The greater the value, the faster you will move as the cursor is moved away from the center circle icon. Zoom Tool As discussed earlier, a single click on the Zoom tool zooms in on the current view by a factor of 25%. This is controlled by the Enable single click incremental zoom check box. When this check box is not checked, a single click on the tool has no effect. Some users fi nd the single-click zoom confusing. Look and Orbit Tool Options By default, when the Look tool is used and the cursor is moved downward, the view of the model moves up, just as if you were moving your eyes down. If you check the Invert vertical axis for Look tool option, this movement is reversed. In this case, the model moves in the same direction as the cursor. If the Keep scene upright check box is not checked, it is possible to turn the model upside down while using the Orbit tool. This may not be desirable because it can be disorienting. To prevent this, be sure to leave the option checked. Uncheck this option only when you want to use Orbit in a “free-fl oating” mode. Rewind Thumbnail Options Options in the Rewind thumbnail section of the Steering Wheels Settings dialog box control when and how thumbnail images are generated for use with the Rewind tool when view changes are made without using a wheel. There are three options in this area. Only one option can be on. When the Never radio button is on, thumbnail images are never generated for view changes made outside of a wheel. Thumbnail images are created for view changes made with a wheel, which is the case for all three options. When the On demand when the bracket is moved over an empty frame radio button is on, thumbnail images are not automatically generated for view changes made outside of a wheel. The frames for these views display a double arrow icon when the Rewind tool in a wheel is used. However, as the brackets are moved over these frames, thumbnail images are generated. This is the default setting. See Figure 3-30. When the Automatically when a view change occurs option is selected, a thumb- nail image is generated any time a view change is made outside of a wheel. When the Rewind tool in a wheel is used, the frames for these views automatically display thumbnail images. View change made outside of a wheel Thumbnail is generated A B Figure 3-30. A—By default, when the Rewind tool is selected, frames representing view changes made outside of a steering wheel display double-arrow icons. B—As the brackets are moved over the blank frames, thumbnail images are generated of the views created outside of a wheel.