Page 628 - Kitab3DsMax

Part V: Animation and Rendering Basics

Tutorial: Making an airplane follow a looping path
Airplanes that perform aerobatic stunts often follow paths that are smooth. You can see this clearly when
watching a sky writer. In this example, I’ve created a simple looping path using the Line spline primitive,
and you’ll use this path to make a plane complete a loop.
To make an airplane follow a looping path, follow these steps:
1. Open the Looping airplane.max file from the Chap 21 directory on the DVD.
This file includes a simple looping spline path and an airplane created by Viewpoint Datalabs.
2. With the airplane selected, open the Motion panel and click the Trajectories button. Then click
the Convert From button in the Trajectories rollout, and select the path in the Front viewport.
3. If you drag the Time Slider, you’ll notice that the plane moves along the path, but it doesn’t rotate
with the path. To fix this, click the Key Mode Toggle button in the Time Controls to easily move
from key to key. Click the Key Filters button, select only Rotation, and then click the Set Key but-
ton (or press the ' key) to enter Set Key mode.
4. Before moving the Time Slider, click the Set Keys button to create a rotation key at frame 0. Then,
click the Select and Rotate button, click the Next Key button, rotate the plane in the Front view-
port to match the path, and click the large Set Keys button (or press the K key) to create a rota-
tion key. Click the Next Key button to move to the next key, and repeat this step until rotation
keys have been set for the entire path.
5. Drag the Time Slider, and watch the airplane circle about the loop.

Cross-Ref
Max provides an easier way to make the plane follow the path using the Path constraint. To learn more about
constraints, see Chapter 22, “Animating with Constraints and Simple Controllers.” n
Figure 21.9 shows the plane’s trajectory.

Using the Follow/Bank utility
When an object travels along a path that defines its trajectory, it maintains its same orientation without
rotating. Imagine a roller coaster car; it rotates and banks as it moves around the track. This rotation and
banking motion can be added to an object following a path using the Follow/Bank utility. You can access
this utility by opening the Utilities panel and clicking the More button. Double-click the Follow/Bank utility
to load it into the Utilities panel.

Caution
The Follow/Bank utility aligns the local X-axis of the object with the local Z-axis of the spline when the utility is
applied, so you need to correctly orient the object’s pivot point before applying the utility. If you don’t, the object
will be aligned at right angles to the path. n
The Follow/Bank utility lets you enable a Bank option and set its Amount and Smoothness. Another option
allows the object to turn upside down (not recommended for a traditional roller coaster car). Click the
Apply Follow button to add the keys to cause the object to follow and bank. The Samples section deter-
mines how many keys are created.

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