Unity 6.3 — Animation Module Reference

Last verified: 2026-02-13 Knowledge Gap: Unity 6 animation improvements, Timeline enhancements

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Overview

Unity 6.3 animation systems:

• Animator Controller (Mecanim): State machine-based (RECOMMENDED)
• Timeline: Cinematic sequences, cutscenes
• Animation Rigging: Procedural runtime animation
• Legacy Animation: Deprecated, avoid

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Key Changes from 2022 LTS

Animation Rigging Package (Production-Ready in Unity 6)

// Install: Package Manager > Animation Rigging
// Runtime IK, aim constraints, procedural animation

Timeline Improvements

• Better performance
• More track types
• Improved signal system

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Animator Controller (Mecanim)

Basic Setup

// Create: Assets > Create > Animator Controller
// Add to GameObject: Add Component > Animator
// Assign Controller: Animator > Controller = YourAnimatorController

State Transitions

Animator animator = GetComponent<Animator>();

// ✅ Trigger transition
animator.SetTrigger("Jump");

// ✅ Bool parameter
animator.SetBool("IsRunning", true);

// ✅ Float parameter (blend trees)
animator.SetFloat("Speed", currentSpeed);

// ✅ Integer parameter
animator.SetInteger("WeaponType", 2);

Animation Layers

• Base Layer: Default animations (locomotion)
• Override Layers: Replace base layer (e.g., weapon swap)
• Additive Layers: Add on top of base (e.g., breathing, aim offset)

// Set layer weight (0-1)
animator.SetLayerWeight(1, 0.5f); // 50% blend

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Blend Trees

1D Blend Tree (Speed blending)

// Idle (Speed = 0) → Walk (Speed = 0.5) → Run (Speed = 1.0)
animator.SetFloat("Speed", moveSpeed);

2D Blend Tree (Directional movement)

// X-axis: Strafe (-1 to 1)
// Y-axis: Forward/Back (-1 to 1)
animator.SetFloat("MoveX", input.x);
animator.SetFloat("MoveY", input.y);

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Animation Events

Trigger Events from Animation Clips

// Add in Animation window: Right-click timeline > Add Animation Event
// Must have matching method on GameObject:

public void OnFootstep() {
    // Play footstep sound
    AudioSource.PlayClipAtPoint(footstepClip, transform.position);
}

public void OnAttackHit() {
    // Deal damage
    DealDamageInFrontOfPlayer();
}

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Root Motion

Character Movement via Animation

Animator animator = GetComponent<Animator>();
animator.applyRootMotion = true; // Move character based on animation

void OnAnimatorMove() {
    // Custom root motion handling
    transform.position += animator.deltaPosition;
    transform.rotation *= animator.deltaRotation;
}

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Animation Rigging (Unity 6+)

IK (Inverse Kinematics)

// Install: Package Manager > Animation Rigging
// Add: Rig Builder component + Rig GameObject

// Two Bone IK (Arm/Leg)
// - Add Two Bone IK Constraint
// - Assign Tip (hand/foot), Mid (elbow/knee), Root (shoulder/hip)
// - Set Target (where hand/foot should reach)

// Runtime control:
TwoBoneIKConstraint ikConstraint = rig.GetComponentInChildren<TwoBoneIKConstraint>();
ikConstraint.data.target = targetTransform;
ikConstraint.weight = 1f; // 0-1 blend

Aim Constraint (Look At)

// Character looks at target
MultiAimConstraint aimConstraint = rig.GetComponentInChildren<MultiAimConstraint>();
aimConstraint.data.sourceObjects[0] = new WeightedTransform(targetTransform, 1f);

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Timeline (Cutscenes)

Basic Timeline Setup

// Create: Assets > Create > Timeline
// Add to GameObject: Add Component > Playable Director
// Assign Timeline: Playable Director > Playable = YourTimeline

// Play from script:
PlayableDirector director = GetComponent<PlayableDirector>();
director.Play();

Timeline Tracks

• Activation Track: Enable/disable GameObjects
• Animation Track: Play animations on Animator
• Audio Track: Synchronized audio playback
• Cinemachine Track: Camera movement
• Signal Track: Trigger events at specific times

Signal System (Events)

// Create Signal Asset: Assets > Create > Signals > Signal
// Add Signal Emitter to Timeline track
// Add Signal Receiver component to GameObject

public class CutsceneEvents : MonoBehaviour {
    public void OnDialogueStart() {
        // Triggered by signal
    }
}

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Animation Playback Control

Play Animation Directly (No State Machine)

// ✅ CrossFade (smooth transition)
animator.CrossFade("Attack", 0.2f); // 0.2s transition

// ✅ Play (instant)
animator.Play("Idle");

// ❌ Avoid: Legacy Animation component
Animation anim = GetComponent<Animation>(); // DEPRECATED

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Animation Curves

Custom Property Animation

// In Animation window: Add Property > Custom Component > Your Script > Your Float

public class WeaponTrail : MonoBehaviour {
    public float trailIntensity; // Animated by clip

    void Update() {
        // Intensity controlled by animation curve
        trailRenderer.startWidth = trailIntensity;
    }
}

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Performance Optimization

Culling

• Animator > Culling Mode:
  • Always Animate: Always update (expensive)
  • Cull Update Transforms: Stop updating bones when off-screen (RECOMMENDED)
  • Cull Completely: Stop all animation when off-screen

LOD (Level of Detail)

• Simpler animations for distant characters
• Reduce skeleton bone count for LOD meshes

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Common Patterns

Check if Animation Finished

AnimatorStateInfo stateInfo = animator.GetCurrentAnimatorStateInfo(0);
if (stateInfo.IsName("Attack") && stateInfo.normalizedTime >= 1.0f) {
    // Attack animation finished
}

Override Animation Speed

animator.speed = 1.5f; // 150% speed

Get Current Animation Name

AnimatorClipInfo[] clipInfo = animator.GetCurrentAnimatorClipInfo(0);
string currentClip = clipInfo[0].clip.name;

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Debugging

Animator Window

• Window > Animation > Animator
• Visualize state machine, see active state

Animation Window

• Window > Animation > Animation
• Edit animation clips, add events

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Sources

• https://docs.unity3d.com/6000.0/Documentation/Manual/AnimationOverview.html
• https://docs.unity3d.com/Packages/com.unity.animation.rigging@1.3/manual/index.html
• https://docs.unity3d.com/Packages/com.unity.timeline@1.8/manual/index.html