Part of having realistic game AI is having characters play animations at times appropriate to the AI character's state. In this chapter, we will look at animation and how it is integrated with RAIN, both with Unity's legacy animation system and Mecanim.
In this chapter, you will learn about the following:
Why animation management is an important part of game AI
Managing animation with behavior trees and Unity's legacy animation
Managing animation by AI with Unity's Mecanim animation system
When you think about game AI, first you probably think about things such as creating virtual minds and making characters "think". When I first started learning about game AI years ago, I didn't think animation was really important for game AI since it wasn't part of creating a virtual mind. But then I attended some AI sessions at the Game Developers Conference and found out that one of the most discussed topics in AI was integrating AI with animation systems; this is when I realized it really is an important part of game AI. This makes sense since game AI is about modeling real thinking instead of focusing on giving characters the appearance of thinking, so having the characters play animations that match their state is important. We can think of animations as just a visual depiction of the current state of the character.
The method we'll look at for integrating animations with the AI is RAIN's animation integration with Unity. RAIN has an Animation tab (with an icon...
As the first step, create a new scene and add a plane to it with a scale of X equal to 10, Y equal to 1, and Z equal to 10 to give us a floor where characters can walk around (and if you want, change its material so it's not white). Then, add the penelope model to your scene that's at Assets/Objects/penelopeFX. Next, we'll do our basic RAIN setup and add a navigation mesh by going to RAIN | Create NavMesh. Make sure the navigation mesh will cover the floor, so change its Size to 100 and then generate the mesh. Next, create a waypoint route by going to RAIN | Create Waypoint Route, rename it PenelopeRoute, and add a few points in front of the penelope model for the character to walk. Lastly, add a RAIN AI object by selecting penelope and going to RAIN | Create AI. Your screen should look similar to the following screenshot:
The scene for the AI animation demo
If you need more details on how to set up a scene with a character patrolling a path, refer to Chapter 2, Patrolling...
In this chapter, we looked at how to integrate animation with our AI. We saw how to use RAIN's animate node to change the character animation from its behavior tree with both Unity's legacy animation system and Mecanim. In the next chapter, we will go back to discussing character movement across a scene. We will look at more advanced uses of navigation meshes and how to create them in more detail to give our characters better movement.
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