Animation clips in Unity - Step-by-Step Execution

Concept Flow - Animation clips

Create Animation Clip

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Add Keyframes to Clip

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Save Clip Asset

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Assign Clip to Animator

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Play Animation Clip

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Animation Runs on GameObject

This flow shows how an animation clip is created, filled with keyframes, saved, assigned to an animator, and then played on a game object.

Execution Sample

Unity

AnimationClip clip = new AnimationClip();
AnimationCurve curve = AnimationCurve.Linear(0f, 0f, 1f, 5f);
clip.SetCurve("", typeof(Transform), "localPosition.x", curve);
clip.name = "clipName";
AnimatorOverrideController controller = new AnimatorOverrideController(animator.runtimeAnimatorController);
controller["clipName"] = clip;
animator.runtimeAnimatorController = controller;
animator.Play("clipName");

This code creates an animation clip, sets a curve for position, assigns it to an animator, and plays the clip.

Execution Table

Step	Action	Evaluation	Result
1	Create AnimationClip object	AnimationClip clip = new AnimationClip()	clip created, empty animation
2	Add keyframe curve to clip	clip.SetCurve(...) called	clip now animates localPosition.x
3	Assign Animator Controller	animator.runtimeAnimatorController = controller	Animator has controller with clip
4	Play animation clip	animator.Play("clipName")	Animation clip starts playing on GameObject
5	Animation runs	GameObject updates transform each frame	Visual movement according to clip

💡 Animation clip plays until stopped or replaced

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
clip	null	AnimationClip instance	AnimationClip with curve	AnimationClip with curve	AnimationClip with curve	AnimationClip playing
animator.runtimeAnimatorController	null	null	null	Assigned controller	Assigned controller	Assigned controller
animator state	Idle	Idle	Idle	Idle	Playing clipName	Playing clipName

Key Moments - 3 Insights

Why does the animation not play if I forget to assign the Animator Controller?

Without assigning the Animator Controller (see step 3 in execution_table), the animator has no clips to play, so calling Play does nothing.

What happens if I add a curve to the wrong property name?

If the property name in SetCurve is incorrect (step 2), the animation won't affect the intended transform, so no visible change occurs.

Can I play an animation clip without an Animator component?

No, the Animator component is required to play animation clips on a GameObject, as shown in step 4.

Visual Quiz - 3 Questions

Look at the execution_table, what is the state of the animator after step 3?

A Animator has no controller assigned

B Animator is playing the clip

C Animator has controller assigned but not playing

D Animator is disabled

💡 Hint

Check the 'animator.runtimeAnimatorController' and 'animator state' columns in variable_tracker after step 3

At which step does the animation clip start playing on the GameObject?

A Step 4

B Step 3

C Step 2

D Step 5

💡 Hint

Look at the 'Action' and 'Result' columns in execution_table for when Play is called

If you forget to add keyframes to the clip, what will happen when you play it?

A The GameObject will move as expected

B The animation clip will play but no visible change occurs

C The animator will throw an error

D The clip will play a default animation

💡 Hint

Refer to step 2 in execution_table and variable_tracker for the effect of adding curves

Concept Snapshot

Animation clips in Unity are assets that store keyframe data.
Create a clip, add keyframes with SetCurve, save it.
Assign the clip via an Animator Controller to a GameObject.
Use Animator.Play to start the animation.
Without keyframes or controller, animation won't run.

Full Transcript

This visual execution shows how to create and use animation clips in Unity. First, an AnimationClip object is created. Then, keyframes are added to animate properties like position. The clip is assigned to an Animator Controller, which is set on the Animator component of a GameObject. Finally, calling Animator.Play starts the animation, causing the GameObject to move or change as defined by the clip. Variables like the clip object and animator state change step-by-step. Common confusions include forgetting to assign the controller or adding incorrect keyframes. The quizzes test understanding of these steps and their effects.