554 AutoCAD and Its Applications—Advanced Copyright Goodheart-Willcox Co., Inc. long time. Unnecessary detail may bog down the computer. In addition, walkthroughs and fl ybys must be created in views with perspective, not parallel, projection. The “visual quality” of the scene has the biggest impact on the time involved in rendering the animation. An animation can be rendered in any visual style or using any render preset that is available in the drawing. It is a natural tendency to render at the highest level to make the animation look the best. However, a computer animation has a playback rate of 30 frames per second (fps). If a single frame (view) takes three minutes to render, how long will it take to render a 30 second animation? An anima- tion 30 seconds in length has 900 frames (30 fps × 30 seconds). If each frame takes three minutes to render, the entire animation will take 2700 minutes, or 45 hours, to render. Are you willing to wait two or three days for a 30 second movie? How about your boss or your client? There are trade-offs and concessions to be made. Perform test renderings on static views and note the rendering time. Then, decide on the acceptable level of quality versus rendering time and move ahead with it. Walking and Flying Walking and Flying The process for creating a walkthrough or a fl yby is the same. First, the command is initiated. Then, the movement is defi ned and recorded. Finally, the recorded move- ment is saved to an animation fi le. Note: the Animations panel in the Visualize tab on the ribbon may not be displayed by default. When using the 3DWALK and 3DFLY commands, you can move through the scene using the arrow keys or the [W], [A], [S], and [D] keys on the keyboard to control your movements. Once either command is initiated, a message appears from the Help fl yout in the InfoCenter, if balloon notifi cations are turned on. If you expand this message, the key movements are explained. See Figure 21-4. To redisplay this message while the command is active, press the [Tab] key. • Move forward. Up arrow or [W]. • Move left. Left arrow or [A]. • Move right. Right arrow or [D]. • Back up. Down arrow or [S]. • Toggle between walk and fl y modes. [F]. You can also navigate through the scene using the mouse. Press and hold the left mouse button and then drag the mouse in the active viewport to “steer” through the scene. With the 3DWALK command, the camera remains at the same Z value. With the 3DFLY command, the Z position of the camera can change. The steps for creating a walkthrough or fl yby are provided at the end of this section. Position Locator When the 3DWALK or 3DFLY command is initiated, the Position Locator palette appears. See Figure 21-5. The preview in this palette shows a plan view of the scene. The purpose of this window is to provide an overview of the scene, in plan, while you develop the animation. It does not need to be displayed to create an animation and can be closed if it takes up too much space or slows down the rendering. Position and target indicators appear in the plan view to show the location of the camera and its target. The green triangular shape displays the fi eld of view. The fi eld of view (FOV) is the area within the camera’s “vision.” The fi eld of view indicator is only displayed when the target indicator is displayed. By default, the position indicator is red. The target indicator is green by default. These properties can be changed in the General category at the bottom of the Position Locator palette. You can reposition the camera and the target in the plan view simply by picking and dragging either indicator. The effect of the change is visible in the active viewport. 3DWALK Ribbon Visualize Animations Walk Type 3DWALK 3DW 3DFLY Ribbon Visualize Animations Fly Type 3DFLY