How to optimize AnimationTrack.CreateClip()

We are currently creating a game that receives input and creates Unity Timeline at runtime.
After we recognized that performance drops a lot. So we check the profiler and found that one of the problems is AnimationTrack.CreateClip().
AnimationTrack.CreateClip (that is only one line of code) cause 23.92 ms is very huge.


Other problem we already know how to deal with it. But about Timeline we don't know much.
In this case, How could we deal with it? We know that Timeline doesn't design for runtime much.
Is there a way like pooling or pre-create? Or create a custom track that do exactly the same thing but with least features can help?

 

What if we want to modify Timeline at runtime? We create Clip at that instant.

Example:
At runtime, player can control time on the timeline through our UI.
We have a timeline that show player walking forward.

AnimationTrack on Timeline
(0-30 sec) |-----WalkingAnimation--------|

Player rewind time to sec 15 and press spacebar to jump.
We create a clip in AnimationTrack that bind with the jumping animation clip (that length = 5 sec) insert and blend it on track.

(According to my understanding, we need to RebuildPlayableGraph here one time. So player can control time and see the animation show correctly.)

AnimationTrack on Timeline will become like this.
(0-15 sec) |-----WalkingAnimation--------|
(15-20 sec) |-----JumpingAnimation-------|
(20-30 sec) |-----WalkingAnimation--------|

 

Wow! That solution is very smart!
A little more complicated but worth to try.
Thank you very much.

I think, in our game, modifying timeline on realtime is inevitable. So we need to do it as cheapest as possible.
Creating controls track is look cheaper than AnimationTrack. So, it should be solved.

I know it's a little hard to help without context.
But it's a little hard to explain our game without a clip or demo (I can't post it in public forum). But I will try my best.

Our core concept is about time. Players can rewind and look through the future as their wish.
The goal is to control character to the exit. Obstacles are some puzzle and enemies.
Players can move their character and interact with something e.g. switch to open the door.
So we thought the Timeline is fit perfectly well. If we can control the time on timeline we can control time.
We just only need to modify timeline at runtime.
In the Timeline we have already create Track Group of player and enemy.
Track Group contains
- Transform Track that control the transform using Infinite clip
- Animation Track that control animation


This is a mockup used to explain.

We have grids. Player character. Enemies that move go and back from A to B. Exit point.
The slider on UI is mapping to time and also time on Timeline. The scissor button (Trim button) that can trim (or delete) action that happened at later than the present time.
Time only moves when receiving action from the player or slide the slider.
For example scenario.
If I slide the slider I can control time and see what it happens.
Because we still not add any input. We can see the character playing idle animation and don't move anywhere. Enemy moves back and forth from point A to B.


I touch the exit grid to command the character to move to the exit.
The script will calculate the shortest path and calculate what happened.
Then, the scripts will process and modify a timeline base on it.
Player character will try to move to the exit but was seen by the enemy and then was hit and die.


Then, the player needs to slide the slider back to the beginning to rewind the time and press scissor button to cancel move action.
After that, the player slides the slider forward to wait till the enemy move pass to grid B then click to the exit grid.
This time the player character will move pass enemy back to the exit safely.


So I think it inevitably to modify Timeline at runtime.

 

It has a lot of detail. I really appreciate it. It maybe took some time for me to deal with.
I will come back later with some update.

P.S. Sorry for a little late reply. I have to deal with another problem. It's about audio on the Timeline.
I know that Timeline only plays sounds when playing. But I try to do some workaround. Already fine I think.

 

For some update:
We already try the pooling method. I can call it a success. "Create Clip" is vanishing from the profiler. And the game can run smooth.

We create clips, return it to the pool and reuse it.
like this

Code (CSharp):

1. protected virtual TimelineClip CreateTimelineClipFromSnapShot(AnimationTrack track, AnimationLog log)
2.     {
3.         ActionToClipMap clipMap = mapper.GetClipDetail(log.actionType);
4.  
5.         if (clipMap.clip == null)
6.             return null;
7.    
8.         TimelineClip timelineClip = null;
9.         if(clipCaches.Count > 0 && cacheIndex < clipCaches.Count)
10.         {
11.             timelineClip = clipCaches[cacheIndex];
12.             var animPlayableAsset = ((AnimationPlayableAsset)timelineClip.asset);
13.             animPlayableAsset.clip = clipMap.clip;
14.             timelineClip.easeInDuration = 0;
15.             timelineClip.easeOutDuration = 0;
16.             timelineClip.blendInDuration = 0;
17.             timelineClip.blendOutDuration = 0;
18.             timelineClip.start = 0;
19.             timelineClip.timeScale = 1;
20.         }
21.         else
22.         {
23.             timelineClip = track.CreateClip(clipMap.clip);
24.             clipCaches.Add(timelineClip);
25.             // Debug.Log("Create new clip for " + clip.name);
26.         }
27.         ++cacheIndex;
28.  
29.         if(config.blend)
30.             timelineClip.easeInDuration = config.easeInDuration;
31.        
32.         timelineClip.start = RenderUtilities.GetGameTimeFromTimeslot(log.startTimeslot);
33.         timelineClip.duration = RenderUtilities.GetGameTimeFromTimeslot(log.duration);
34.         timelineClip.displayName = clipMap.clip.name;
35.         timelineClip.timeScale = clipMap.speedMultiplier == 0 ? 1 : clipMap.speedMultiplier;
36.  
37.         return timelineClip;
38.     }

It's already fine for our gameplay video now. We will use other methods in the late process later.

P.S. After optimized, sometimes it happens some weird behavior on blending.
The leg of the character stretches out like a monster in some movement.
The tail and the back part of the cat stretch out like a giraffe in some walk movement.
We already call rebuildGraph whenever we modify the timeline. So we still can't figure it out.
I guess we still forgot to clear something when we return the clip back to pool.