# custom_timeline

**Repository Path**: liuyaoif/custom_timeline

## Basic Information

- **Project Name**: custom_timeline
- **Description**: 扩展unity的timeline，实现自定义轨道（track）和clip。
- **Primary Language**: Unknown
- **License**: WTFPL
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 1
- **Forks**: 3
- **Created**: 2021-12-31
- **Last Updated**: 2024-09-12

## Categories & Tags

**Categories**: Uncategorized

**Tags**: Unity

## README

# Timeline扩展方案
> Timeline默认的Track和Clip如下。  
> ![avatar](Document/TimelineTrack.png)  
> 如果想让Timeline驱动游戏逻辑，需要自定义TrackAsset，PlayableBehaviour和PlayableAsset 来实现。目前有3种方式使用自定义功能。  
> ||
> |:----:|
> |Playable track|
> |ClipBehaviour|
> |TrackBehaviour|
> 
## 1. Playable track方式
1. 添加一条Playable track。
![avatar](Document/AddPlayableTrack.png)。
1. 创建一个PlayableAsset脚本: create->Playables->Playable Assets C# Script。
2. 拖到Playable track上。
> 这个方法受限制严重，不推荐使用。

## 2. ClipBehaviour
1. 创建一个TrackAsset的C#脚本。
```CSharp
[TrackClipType(typeof(TextTLAsset))]
[TrackBindingType(typeof(Text))]
public class TextTLTrack : TrackAsset
{
    /// <summary>
    /// TrackAsset在创建时必然会遍历所有的Clip,有机会给所有的clip传值
    /// </summary>
    /// <param name="graph"></param>
    /// <param name="gameObject"></param>
    /// <param name="clip"></param>
    /// <returns></returns>
    protected override Playable CreatePlayable(PlayableGraph graph, GameObject gameObject, TimelineClip clip)
    {
        PlayableDirector direct = graph.GetResolver() as PlayableDirector;
        //在Clip创建时传参
        TextTLAsset asset = clip.asset as TextTLAsset;
        asset.Label = direct.GetComponent<CutScenePlayer>().label;

        return base.CreatePlayable(graph, gameObject, clip);
    }
}
```
> TrackAsset实现CreatePlayable方法，这条Track上每一个Clip（拖拽一个Asset就有一个Clip）都会调用一次这个方法。利用这个方法给Asset传参数。这里传递了label这个控件。

2. 创建一个PlayableAsset的C#脚本。
```CSharp
[System.Serializable]
public class TextTLAsset : PlayableAsset
{
    public Text Label { set; get; }
    public string Content;

    /// <summary>
    /// 在创建时向Behaviour传引用
    /// </summary>
    /// <param name="graph"></param>
    /// <param name="go"></param>
    /// <returns></returns>
    public override Playable CreatePlayable(PlayableGraph graph, GameObject go)
    {
        //创建ClipBehaviour
        var playable = ScriptPlayable<TextTLBehaviour>.Create(graph);
        var behaviour = playable.GetBehaviour();
        behaviour.Label = Label;
        behaviour.Content = Content;

        return playable;
    }
}
```
> PlayableAsset实现CreatePlayable方法，并Create一个PlayableBehaviour，这个Behaviour的生命周期是绑定这个Asset的。也就是说有多个Clip就有多少Behaviour实例，所以称之为<font color=#FF4500>ClipBehaviour</font>。Asset向自己的Behaviour传参Label控件和Content参数。

3. 创建一个PlayableBehaviour的C#脚本。
```CSharp
[Serializable]
// A behaviour that is attached to a playable
public class TextTLBehaviour : PlayableBehaviour
{
    public Text Label;
    public string Content;

    public override void OnBehaviourPlay(Playable playable, FrameData info)
    {
        if (Label != null)
        {
            Label.text = Content;
        }
    }

    public override void OnBehaviourPause(Playable playable, FrameData info)
    {
        if (Label != null)
        {
            Label.text = string.Empty;
        }
    }
}
```
> Behaviour实现OnBehaviourPlay和OnBeahviourPause两个方法，当时间线走到对应的Asset时就会调用到。
> ![avatar](Document/ClipBehaviour.png)
> 这个方案适合于做连续台词等不需要混合的需求。

## 3. TrackBehaviour
> TrackBehaviour方式和ClipBehaviour大部分相似，也是需要自定义的TrackAsset，PlayableBehaviour和PlayableAsset。区别在于PlayableBehaviour由TrackAsset创建而不是Asset。
1. 创建TrackAsset
```CSharp
[TrackClipType(typeof(ColorTLAsset))]
[TrackBindingType(typeof(Text))]
public class ColorTLTrack : TrackAsset
{
    public ScriptPlayable<ColorTLBehaviour> TrackBehaviourPlayable;
    private ColorTLBehaviour behaviour;

    //创建Track混合器而不是Clip
    public override Playable CreateTrackMixer(PlayableGraph graph, GameObject go, int inputCount)
    {
        //取外部引用
        PlayableDirector direct = graph.GetResolver() as PlayableDirector;
        Text label = direct.GetComponent<CutScenePlayer>().label;

        //创建TrackBehaviour并设置inputCount，inputCount就是Clip的个数
        TrackBehaviourPlayable = ScriptPlayable<ColorTLBehaviour>.Create(graph);
        TrackBehaviourPlayable.SetInputCount(inputCount);
        behaviour = TrackBehaviourPlayable.GetBehaviour();

        //传递参数
        behaviour.label = label;
        behaviour.track = this;

        return TrackBehaviourPlayable;
    }
}
```
> 注意，TrackBehaviour是TrackAsset创建，生命周期绑定到了TrackAsset上，当Track启动、结束后触发Behaviour的OnBehaviourPlay和OnBeahviourPause，这个Behaviour和Clip是<font color=#FF4500>没有关系的</font>。
2. 创建PlayableAsset
```CSharp
[System.Serializable]
public class ColorTLAsset : PlayableAsset
{
    public Color CurColor;

    public override Playable CreatePlayable(PlayableGraph graph, GameObject go)
    {
        return Playable.Create(graph);
    }
}
```
> TrackBehaviour方案的Asset比较简单，只是暴露参数用于设置就好了。
3. 创建PlayableBehaviour
```CSharp
public class ColorTLBehaviour : PlayableBehaviour
{
    public Text label;
    public ColorTLTrack track;

    //OnBehaviourPlay和OnBehaviourPause方法和Clip没关系了，所以只能在ProcessFrame（Update）中获取
    public override void ProcessFrame(Playable playable, FrameData info, object playerData)
    {
        //取ClipCount
        int clipCount = playable.GetInputCount();

        int index = 0;
        for (int i = 0; i < clipCount; i++)
        {
            float weight = playable.GetInputWeight(i);
            //Weight > 0f的Clip是进入了的Clip，可能有多个
            if (weight > 0f)
            {
                index = i;
                break;
            }
        }

        //根据Clip的Index取Clip和Asset
        ColorTLAsset curAsset = null;
        foreach (var itr in track.GetClips())
        {
            if (index == 0)
            {
                curAsset = itr.asset as ColorTLAsset;
            }
            index--;
        }

        //赋值
        if (label != null)
        {
            label.color = curAsset.CurColor;
        }
    }
}
```
> 该方法适合自动控制有融合的多个Clip之间的混合。[Timeline混合Demo](https://blogs.unity3d.com/2018/09/05/extending-timeline-a-practical-guide/)