9. Character animation

• In this section, we will cover character animation.
• Examples:
  • Player animation tutorial playlist
  • Procedural (spider) animation tutorial
  • Procedural animation in Rain World and Synthetic Selection

Preparation

• Obtain animation assets from Mixamo: search for animations in the Animations tab and 3D models in the Characters tab.
• Import the model and animations into a new folder named "Models/Player".
  • Extract textures and materials from the character model.
  • Place the model as a child of the Player GameObject in the scene.
  • Disable the Capsule's renderer, leaving it solely for the player's collider.
• Add the Animator component to the player model in the inspector.
• Create an "Animations" folder and an Animator Controller named "PlayerController" within it. Assign this controller to the Animator component.
• Expand animation assets and copy "Animation Clip" out of each one (click on it and press ctrl-d), and rename them appropriately (e.g., Idle, Walking, Running, Fire, etc.), then move them to the Animations folder.

Animator

• Open the Animator by double-clicking the PlayerController.
  • Drag the Idle animation clip into the Animator, setting it as the Default state (connected to the Entry state).
• Enable the "Loop Time" field for the Idle animation clip to allow looping.
• Repeat these steps for the Walking and Running animation clips.
  • Enable the "Loop Pose" field to keep the player model stationary during these animations.

Bool parameters: isWalking, isRunning (and fire trigger)

• Include Walking and Fire animations in the Animator.
• Establish a transition from the Idle state to the Walking state.
  • In the Animator window, navigate to the "Parameters" tab and add a new bool parameter: "isWalking".
  • Assign a condition to the transition from Idle to Walking: "isWalking = true" (to switch from Idle to Walking when the player is moving).
  • Access the "isWalking" variable from the PlayerController script:
    • Declare public Animator animator;
    • Set this field in the Player's inspector.
    • In the Update method, set animator.SetBool("isWalking", true); if moveDirection.magnitude > 0, otherwise set it to false.
• Disable the "Has Exit Time" field for each transition.
• Establish a transition from Walking to Idle (activated when the player is not walking).
• Create a transition from "Any State" to the Fire state (and add a new trigger parameter: "fire"). Use this parameter as the condition for the transition.
  • This transition allows the state machine to switch to the Fire state regardless of the current animation state.
  • In the transition settings, set the transition offset to 0.25 to synchronize the firing animation with the trigger activation.
  • In script, set this trigger when the player shoots: animator.SetTrigger("fire");.
• Add a transition from Fire to Exit (looping the state machine back to the Entry state).

• Add the Running animation into the animator.
• Include a new bool parameter: "isRunning". Adjust it in the PlayerController script by assigning true if rb.velocity.magnitude > 5.
• Establish transitions from Walking to Running, from Running to Walking, and from Running to Idle, utilizing appropriate parameters as conditions.

1D Blend trees and float parameter speed

• Right-click in the animator window > Create State > From New Blend Tree.
  • A new float parameter might appear, rename it to "speed".
    • Set its value from the PlayerController script: animator.SetFloat("speed", rb.velocity.magnitude);.
• Remove Walking and Running states from the animator.
  • Establish a new transition from Idle state to the Blend Tree and one transition back to the Idle state.
  • The transition from Idle to Blend Tree should have one condition: speed > 0.1
  • The transition from Blend Tree Idle should have one condition: speed < 0.1

• Double click on the Blend Tree to open it.
  • Click on the Blend Tree node.
  • In the inspector, add two motions: Walking and Running.
  • Set the threshold on the Running motion to be 6.5 (you first have to disable "Automate Threshold").
    • This value represents approximately the maximum speed the player moves at, although it may vary depending on your implementation.
• Now, the player character will be animated accordingly based on the speed at which they move. However, this setup currently only accounts for forward motion.

2D Blend Tree and float parameters velocityX and velocityY

• Start by creating a new Blend Tree and setting it as the default state (right-click on it).
  • Ensure that the Entry has a transition leading to the new Blend Tree. Remove the Idle state and any previous Blend Trees.
  • Double-click the new Blend Tree to open it.
• Click on the Blend Tree node and set the Blend Type to "2D Freeform Directional" in the inspector.
• Create two float parameters: velocityX and velocityY.
• Add all desired motions to animate (such as Idle, Walking, Running, Strafe left, Strafe right, etc.).

• You can move the points around.
  • Blue points indicate favored velocities for animations, while the red point represents the current velocity in both x and y directions.
• Set the x and y velocity in the script. The velocity should be relative to the look direction.
  • You will have to have acess to the lookDirection variable. You can declare it outside the FixedUpdate method.

Quaternion targetRotation = Quaternion.LookRotation(lookDirection);
Vector3 relativeVelocity = Quaternion.Inverse(targetRotation) * rb.velocity/6.5f;
animator.SetFloat("velocityX", relativeVelocity.x);
animator.SetFloat("velocityY", relativeVelocity.z);

• Now player movement should be animated properly.
  • But shooting animation stops all other animations (solvable using animation layers), and we are missing jump and death animations.

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