'Building Interactive Worlds in 3D': Creating a Walk Animation and Exporting to Virtools

This is the next in a series of excerpts from Building Interactive Worlds in 3D by Jean-Marc Gauthier. For the next few months, we will be present chapters from a section entitled The Basic 3D Kit.

Lets create a looped animation of a walk for the Cyclop character. First you create a walk cycle that you later loop over and over again to create the illusion of a continuous walk. This method allows you to use a short walk animation that will be optimized for 3D interactive content. The walk cycle takes 60 frames. The first and the last poses are the same so the cycle can be repeated without any visible discontinuity. The following illustration shows how to move the limb locators for the first posture of the Cyclop.

To Animate Mr. Cyclop

To key the first frame, first select the Body locator. Second, press the Shift + W keys. Repeat the same operations with the other locators:

Select the Left Leg locator. Press the Shift + W keys.

Select the Right Leg locator. Press the Shift + W keys.

The posture of the character is recorded at frame 1.

Select the Body locator, and move the character 15 units ahead. You can adjust the position of the leg locators to get a posture similar to the previous one.

You can specify the length of the animation in the End Time box located on the left of the Playback Animation Controls.

Move the Time Slider to frame 60, and record the posture by keying the locators again.

Go to the top menu, and select Animation > Animation Snapshot.

Specify time range = 1-60 and increment = 60. Press Snapshot. When you move the Time Slider back to the first frame you will notice that Maya took a snapshot of the character at frame 60.

Select the snapshot posture in the Perspective window. Display a wireframe version of the snapshot posture.

Go to the top menu and select Display > Object Display > Template.

You can play back your animation by pressing the Play button located with the Playback Controls, in the lower right corner of your screen.

When you record the posture at frame 30, the legs and arms will be in the opposite direction of the postures previously created at frame 1 and 60.

Lets Create Two More Postures:

One posture is at frame 15, and the other one is at frame 45. Fine tune the bending of the feet at these two frames, and press the Shift + E keys to record the keyframe.

The Graph Editor Helps You Tweak the Animation:

Go to the top menu and select Window > Animation Windows > Graph Editor. Select the keyed locators, and in the Graph Editor choose View > Frame All. The curve is smooth by default. You can make it linear by clicking on the Linear Tangent button. Please remember to delete the snapshot posture that you previously created.

To Add a Point Light to Your Scene

Go to the top menu and select Create > Lights > Point Light. Save your work.

How to Export the Character to Virtools

Please make sure that the Virtools2Maya exporter plug-in is installed on the copy of Maya that you are using.

To activate the plug-in, go to the top menu and select Window > Settings/Preferences > Plug-in Manager.

Select and enable the plug-in.

Lets Export the Character To Virtools

Go to the top menu and select File > Export All. Select the box on the right side of the text. In the Export All Options dialog window, select the following parameters:

• Under File Type, select Virtools

• Under Export Options choose

  • Type = Character

  • Hierarchy = Full

  • Export = All

    Exported Objects = Meshes, Lights, Normals, Textures, Cameras

• Under Textures Options choose Include Textures in File = ON

• Under Animation Options choose