Animator Access Generator

Code generator utility for Unity game engine. Creates a class to conveniently access Animator states and parameters. The goal is to facilitate access to Animator states and parameters. Further on encapsulting access through dedicated methods makes it possible to detect potential problems and inconsistencies already at compile time.

See also the quick overview at YouTube, walkthrough video and blog.

Quick Start


  • Unity 4.3 is needed
  • Download the current stable release from GitHub
  • Unzip and copy all files to some location under your Assets directory but NOT under any editor directory.

Generating Code:

  • In the hierachy view select a game object that contains an Animator component having a valid controller
  • Go to the new menu item Animator Access / Create Animator Access
  • Choose a file name and the output directory where to place the C# file (has to be under Assets directory)
  • Say Yes when the dialog appears about adding the component to the game object.

Usage example

Setup (related to provided ExampleScene.unity):

  • Game object ExamplePlayer contains an Animator component
  • Generated class is ExamplePlayerAnimatorAccess.cs
  • Another component Player is attached to this game object too. It uses ExamplePlayerAnimatorAccess in its FixedUpdate method to control animations
  • Animator states are:
    • Idle, Jumping, Walking and Yawning in layer 0 (Base Layer)
    • Centered, Rotate-Left and Rotate-Right in layer 1 (Rot)
  • Animator parameters are:
    • JumpTrigger (trigger) and
    • YawnTrigger (trigger) and
    • Rotate (int) and
    • Speed (float)

To use ExamplePlayerAnimatorAccess define a member in Player.cs and assign a reference in Awake ():

AnimatorAccess.ExamplePlayerAnimatorAccess anim;
void Awake () {
    anim = GetComponent < AnimatorAccess.ExamplePlayerAnimatorAccess > ();

Now you have convenient access to all parameters and animator states. Aside from using parameter and state hash IDs directly, there are predefined methods for querying the state (prefix Is) and Get and Set methods to access parameters in a type safe way like IsWalking () SetSpeed ():

void FixedUpdate () {
    if (anim.IsWalking ()) {
        // set speed 
        anim.SetSpeed (speed);
        // alternatively you can use hash IDs directly but this is more cumbersome:
        // animator.SetFloat (anim.paramIdSpeed, speed);

Events are another powerful way to use the generated component. The following code will register some event handlers which are called whenever a state or transition meets the given criteria:

void OnEnable () {
    anim.State (anim.stateIdIdle).OnActive += OnIdle;
    anim.TransitionTo (anim.stateIdWalking).OnStarted += OnStartedTransitionToWalking;
void OnIdle (AnimatorAccess.StateInfo info, AnimatorAccess.LayerStatus status) {
    // Called repeatedly on each cycle as long as state 'Idle' is active
void OnStartedTransitionToWalking (AnimatorAccess.TransitionInfo info, AnimatorAccess.LayerStatus status) {
    //  Called once every time a transition to state 'Walking' is starting

Concept And Workflow

Basic Idea

Whenever you have made any changes in the Animator window like adding, renaming or deleting states or parameters, you should update the animator access component. Animator Access Generator analyses the existing version of the component to be generated and works with a two-step procedure to handle changes:

  • Previously valid members (i.e. Animator parameters and states) are detected and marked with the Obsolete attribute
  • Those members in the previous version that were already marked as Obsolete will be removed

The basic idea is to give you the chance to refactor your code without having uncompileable code. If there are any references to members that are not valid any longer, obsolete warnings guide you where you have to make changes:

(CS0168: Animator state or parameter is no longer valid and will be removed in the next code generation...)

Workflow Using The Custom Editor

The generated component has a custom inspector window:

Custom Editor up to date

The status is updated every 30 seconds automatically. Use the Check button to force a status update immediately. Check will not perform any changes but is meant to preview what will happen on an update. Hovering the mouse over an entry will show a tooltip with more information

Supposed we made 3 changes: A new state Running, New trigger parameter LookUp and renaming of parameter Rotate to RotateTo

This will look like:

Custom Editor having changes

  1. New field stateIdRunning and an IsRunning () method for Running
  2. Field paramIdLookUp and SetLookup () method for LookUp (triggers don't have Get methods)
  3. Field and methods for RotateTo including a Get method as this is an int
  4. The code of the previously named parameter Rotate will be marked as obsolete i.e. paramIdRotate, GetRotate and SetRotate.

Push the Update button to perform the changes and regenerate the component's source code. Note that the changes are not refreshed automatically. Most often you will like to first view and adopt the changes in MonoDevelop and then run your game in Unity.

The Refresh button forces Unity to reload the changes from disk (s. Advance Topics on automatic refreshing).

Undo performs a roll back to the previous version. Note that there is only one backup saved. Again there is no automatic refresh so push Refresh after Undo.

Using The Generated Code in MonoDevelop

In this section we assume the example setup described in the usage example above. The code including a working example scene can be found in the provided Example folder s. Scripts. See section Naming Conventions below for more about how member names are built.

Accessing Parameters

For every Animator parameter a public integer field is generated that contains the parameter name hash. Depending on the parameter type, additional Get- and Set-methods are generated . For example an integer parameter rotate will produce the following 3 members in the generated class:

public int paramIdJumpTrigger;
public void SetRotate (int newValue) { ... }
public int GetRotate () { ... }

In general it is not recommended to use the paramIdJumpTrigger directly. Instead call the corresponding Get and Set methods. This makes your code more robust because the compiler will detect type mismatches already if you for example try to set an integer to a boolean parameter. So in your Player.cs you just write

anim.SetRotate (myValue);

Note that there will be no Get method for trigger parameters. On the other hand a float produces 2 Set methods like in class Animator.

Working with States

Like with parameters integer member fields are created for holding the name hash of each state. For checking the current state of a specific layer two bool methods are generated:

public int stateIdIdle;
public bool IsIdle () { ... }
public bool IsIdle (int nameHash) { ... }

The parameterless version automatically looks up the current state as the correct layer is baked in during generation. The overlodaded version expects a state name hash from animator.GetCurrentAnimatorStateInfo (layerOfState).nameHash and is useful when you do a bunch of checks and don't want .

Events on States And Transitions

All generated AnimatorAccess components provide an interface to register listener callbacks for a wide range of use cases. Events occur when a specific condition is met that is related to states or transitions.

The condition is defined when a listener subscribes to a certain event by using += operator as the standard C# event mechanism is used. That means there will be no notification as long as no listener has subscribed. Compared to Unity's SendMessage approach this design has advantages regarding performance as otherwise there would have been hundreds of SendMessage calls every second even if no component is interested.

Some examples for registering listeners:

anim.AnyState (0).OnChange += OnStateChangeLayer0:
    // called whenever the state changes in layer 0; Leave layer empty to observe all layers
anim.State (anim.stateIdIdle).OnEnter += OnIdleEntered;
    // called once when 'Idle' state is entered
anim.Transition (anim.stateIdIdle, anim.stateIdWalking).OnStarted += OnIdleToWalking;
    // called when the transition from 'Idle' to 'Walking' has started
anim.TransitionFrom (anim.stateIdJumping).OnActive += OnTransitionFromJumping;
    // called every frame as long as any transition from State 'Jumping' is ongoing

and their method definitions:

void OnIdleEntered (StateInfo info, LayerStatus status) { ... }
void OnTransitionFromJumping (TransitionInfo info, LayerStatus status) { ... }

Hint: If you feel that entering a state is too late for the action to perform, use a transition OnStarted event instead to win the transition time.

Performance: Registering a listener implies an entry in dictionary and a call to its check method every frame. As there are only a few lines of basic C# code executed, it should not have any perfomance penalties.

Runtime Details about States And Transitions

An AnimatorAccess component provides access to a couple of information about states and transitions that is otherwise not available at runtime. This lets you easily look up the name, speed, ... for debugging purposes. The properties

public Dictionary<int, StateInfo> StateInfos;
public Dictionary<int, TransitionInfo> TransitionInfos;

provide dictionaries having the state / transition name hash as key:

  • StateInfo contains clear text name, layer, layer name, tag, speed, ...
  • TransitionInfo contains clear text name, layer, source, destination, duration,

Transition name hashes are not provided an integer member variable like for states and parameters. Either you have an ID in case of an event listener and thus the TransitionInfo or you can iterate the TransitionInfos dictionary and search for whatever you are looking for. Never rely on state or transition names! Use them for debugging only.

Both properties are initialised deferred at the time of the first access or when an event listener is registered. Thus if you are afraid of performance drawbacks don't use them and (refrain from events).

Renaming And Efficient Handling of Obsolete Warnings

Although generated code should not be edited, it can be pretty useful to do so temporarily to quickly update your other code. If you rename Animator parameters, states or layers that are referenced in your own code, you will get warnings about using obsolete members. While single occurrences are easy to maintain, renaming of a widely used parameter would be painful to replace in code.

To do this more efficiently use refactoring and rename the obsolete member to the new name. Suppose there are several calls to SetRotate in the example above. We want to change all these calls at once to point to the new method SetRotateTo:

Go to the obsolete method SetRotate (int newValue) in the newly generated file ExamplePlayerAnimatorAccess.cs and rename it to SetRotateTo.

Custom Editor having changes

Yes, there is already our new method SetRotateTo having exactly the same signature and now we have two of them. But that's the clue: After renaming is done, simple delete the obsolete version - ready. Now all references point to the correct method.

Errors in MonoDevelop

There are three known situations when you may get errors:

  1. Obsolete warnings were ignored and the next Update was triggered. Then all obsolete members are removed and references to these will fail
  2. You changed state and parameter hash prefix settings to contain the same string, removed a parameter and create a state with the same name
  3. Generated code was edited so that a naming conflict arose.

If Undo does not help, most problems can be solved pretty similar the way we handled warnings. Do single changes manually and a bunch of changes with the refactoring strategy. If there are many places referring to a missing member, manually introduce it as dummy and then use refactoring.

Naming Convention And Customising

You can customise the way how to generate parameter and method names in the Settings window. All access methods start with Is, Get or Set. This cannot be changed but the pattern for the appended item name can be modified. You can for example define that all animator state query methods (Is...) contain the prefix State before the name e.g. IsStateIdle ().

Be careful with changes for the hash ID member variables prefixes. States and parameters should have different prefixes to avoid naming conflicts.

By default the Layer name is ignored for layer 0 and prepended for all other layers.

Avoid non-ANSI characters. Field names are converted to match the pattern [a-z_][a-zA-Z0-9_]. Non-matching characters are changed to an underscore.

Look at the tooltips in the Settings windows or go to for a complete description.

Advanced Topics

See for more about:

  • Configuration via Settings window
  • Persistent Storage Location
  • SmartFormat Template
  • Moving Animator Access Menu
  • Git Subtree Integration / Contributing
  • File Specific Configuration
  • Extending BaseAnimatorAccess

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