Unityでanimファイルを指定秒数で分割して出力するエディタ拡張です

AnimationSplitter.cs

using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnityEditor;
using UnityEngine;

namespace akr.Unity.Editor.Animation
{
    public class AnimationSplitter : EditorWindow
    {
        private AnimationClip animClip;
        private float splitSeconds = 60.0f;

        [MenuItem("akira/AnimationSplitter")]
        private static void Create()
        {
            GetWindow<AnimationSplitter>("AnimationSplitter");
        }

        private void OnGUI()
        {
            animClip = EditorGUILayout.ObjectField("Animファイル", animClip, typeof(AnimationClip), true) as AnimationClip;
            splitSeconds = EditorGUILayout.FloatField("分割秒数", splitSeconds);
            if (GUILayout.Button("分割!"))
            {
                if (animClip != null)
                {
                    var animEvents = AnimationUtility.GetAnimationEvents(animClip);
                    foreach (var animEvent in animEvents)
                    {

                    }
                    var curveBindings = AnimationUtility.GetCurveBindings(animClip);
                    var newClips = new List<AnimationClip>();
                    AnimationCurve tempCurve = null;
                    foreach (var curveBinding in curveBindings)
                    {
                        var animationCurve = AnimationUtility.GetEditorCurve(animClip, curveBinding);
                        int count = 0;
                        tempCurve = new AnimationCurve();
                        if (animationCurve.keys.Length > 0)
                        {
                            Keyframe lastFrame = animationCurve.keys[0];
                            foreach (var frame in animationCurve.keys)
                            {
                                while (newClips.Count <= count)
                                {
                                    newClips.Add(new AnimationClip());
                                }
                                if (frame.time > (count + 1) * splitSeconds)
                                {
                                    Debug.Log($"NewCurve start time:{tempCurve.keys.First().time} endtime:{tempCurve.keys.Last().time}");
                                    //分割時間に合うように最後のキーを最終秒に同じ値で置く
                                    var finalFrame = lastFrame;
                                    finalFrame.time = splitSeconds;
                                    tempCurve.AddKey(finalFrame);
                                    AnimationUtility.SetEditorCurve(newClips[count], curveBinding, tempCurve);
                                    //分割時間以上の空白がある場合0秒と分割秒地点に同じ値で置く
                                    int nextcount = (int)(frame.time / splitSeconds);
                                    if (nextcount - count > 1)
                                    {
                                        for (int tmpi = 0; tmpi < nextcount - count; tmpi++)
                                        {
                                            tempCurve = new AnimationCurve();
                                            finalFrame = lastFrame;
                                            finalFrame.time = 0.0f;
                                            tempCurve.AddKey(finalFrame);
                                            finalFrame = lastFrame;
                                            finalFrame.time = splitSeconds;
                                            tempCurve.AddKey(finalFrame);
                                            while (newClips.Count <= count + tmpi + 1)
                                            {
                                                newClips.Add(new AnimationClip());
                                            }
                                            AnimationUtility.SetEditorCurve(newClips[count + tmpi + 1], curveBinding, tempCurve);
                                        }
                                    }
                                    count = nextcount;
                                    tempCurve = new AnimationCurve();
                                    lastFrame.time -= splitSeconds * count;
                                    if (lastFrame.time < 0.0f) lastFrame.time = 0.0f;
                                    if (lastFrame.time > splitSeconds)
                                    {
                                        Debug.Log("ERROR time");
                                    }
                                    tempCurve.AddKey(lastFrame);
                                }
                                var currentFrame = frame;
                                currentFrame.time -= splitSeconds * count;
                                if (currentFrame.time > splitSeconds)
                                {
                                    Debug.Log("ERROR time");
                                }
                                if (currentFrame.time < 0.0f) currentFrame.time = 0.0f;
                                tempCurve.AddKey(currentFrame);
                                lastFrame = frame;
                            }
                            Debug.Log($"NewCurve start time:{tempCurve.keys.First().time} endtime:{tempCurve.keys.Last().time}");
                            AnimationUtility.SetEditorCurve(newClips[count], curveBinding, tempCurve);
                        }
                    }

                    var path = "Assets/Resources/Split";
                    if (Directory.Exists(path) == false) Directory.CreateDirectory(path);
                    for (int num = 0; num < newClips.Count; num++)
                    {
                        var outputPath = path + $"/{animClip.name}_s{num + 1}.anim";
                        AssetDatabase.CreateAsset(newClips[num], AssetDatabase.GenerateUniqueAssetPath(outputPath));
                        AssetDatabase.SaveAssets();
                    }
                    AssetDatabase.Refresh();
                }
            }
        }
    }
}