In Unity, two systems can be used for animation
Animations are premade sets of visual motions
Animating a model without a rig is impossible (or impossibly difficult). The reason is that without a rig, the computer has no way of knowing which parts of a model are supposed to move and how they are supposed to move. The rig dictates the parts of a model that are rigid, which are often called bones. It also dictates which parts can bend. These bendable parts are called joints
Generally speaking, the modeling, texturing, rigging, and animations are all created by professionals known as 3D artists in programs such as Blender, Maya, 3D Studio Max, or any other 3D creation software
In this section, you begin working with a model that has already been rigged, and you acquire animations specifically made for the model. You acquire a model from the Unity Asset Store
To access the Unity Asset Store, click Window > Asset Store. You may be asked to log in. Once the Asset Store is loaded, locate the search window and search for Warrior
Locate the free model 3dsmax Bip Warrior Anim Free and click Import (see Figure 17.3). When the Import Package dialog appears, ensure that everything is selected and click Import.
You should now notice a new folder on your Project view named 3dsmax Bip Warrior Anim Free
The soldier model comes with a demo scene. You can find this demo in the Scenes folder under the folder 3dsmax Bip Warrior Anim Free. Opening this scene will allow you to test out the model with the various animations applied
You can locate the model that you will be using in the Models folder under the newly created 3dsmax Bip Warrior Anim Free folder. The model is named Soldier_f_0. Locate the model and select it. In the Inspector view, you should see three primary tabs: Model, Rig, and Animations
The Model tab is responsible for all of the settings that dictate how the model itself is imported into Unity
Under the Rig tab, ensure that the Animation Type property is set to Legacy and that the Generation property is set to Store in Root (New)
Under the Animations tab, uncheck the Import Animation check box, and then click Apply.
You can always look at the model in the Hierarchy view. Generally, a rigged model will contain several child game objects. These objects will correspond with the various rigging joints.
Locate the Animations folder under the 3dsmax Bip Warrior Anim Free folder. This folder contains four available animations: death, idle0, idle1, and idle2. Selecting any of these animation assets will allow you to modify their Wrap Mode property and preview them.
As mentioned previously, animations can be applied to a model by dragging them onto the Animations property of the Animation component
To play an animation on a model, you need to use the transform.animation.Play() method