运行时合并Mesh

Init

我的游戏里有大量Spine动画, 我查了一下Unity Profiler, 最高时一帧调用 SkeletonRenderer.Update 2500+次. 我在想可以在加载时将同属于一个人的Spine合并成一个吗? 有人这么做过吗?

Spinebot

在Unity中合并多个Spine骨架的Mesh是一个复杂的任务，因为Spine使用的是普通的MeshRenderer而不是SkinnedMeshRenderer，并且每帧都会更新Mesh。虽然理论上可以在加载时合并属于同一个角色的Spine骨架，但这需要对SkeletonData进行编程合并，并更新所有的交叉引用（例如骨骼索引）。这种方法相当复杂，因此不推荐，除非绝对必要。

如果你想优化性能，可以考虑以下方法：

确保你的Spine骨架动画和Mesh更新是通过Unity的动态批处理系统自动批处理的。
使用SkeletonRenderSeparator来分割骨架的渲染，以便更好地控制渲染顺序。
在运行时只生成一次Mesh，并在后续的渲染调用中重复使用，以减少每帧计算Mesh顶点的开销。

Harald

@Init Do you mean SkeletonRenderer.LateUpdate or SkeletonAnimation.Update? In general, if any of the two is called 2500 times in a single frame, you either have 2500 skeletons, which I doubt, or you're triggering a lot of unnecessary redundant calls. Calling LateUpdate() or Update(0) manually can be justified e.g. after changing animations to see an immediate change this frame, but this should by far not happen each frame. You could check from where the majority of calls is originating, as it sounds like a bug in your game-code.

Init

Harald 很抱歉这么久才回复, 我重新检查了一下是SkeletonAnimation.Update
我的游戏中每个角色有至少7个spine动画(MMORPG), 同屏最大角色数量300+, 最常见的峰值是100个左右角色同时存在.
最关键的一点是我的动画是帧动画而非骨骼动画, 这可能是出现问题的原因....

Harald

@Init No need to apologize, thanks for the additional information.

If SkeletonAnimation.Update() is called 2500+ times for 100-300 skeletons, this still means that there are about 10x as many Update calls happening than necessary.

So still this question would be important to answer:
You could check from where the majority of calls is originating?

One thing you might be missing, if you're having lots of skeletons outside the screen which need no animation or mesh updates:
Please be sure to set Advanced - Update When Invisible mode at the SkeletonAnimation component to something else than Full Update, otherwise you will perform a full update for each off-screen skeleton even though nothing is visible. You could e.g. set it to Only Animation Status or Only Event Timelines if you need some events from the animation to still trigger at precise timepoints.

Init 最关键的一点是我的动画是帧动画而非骨骼动画, 这可能是出现问题的原因....
The most important point is that my animation is frame animation rather than skeleton animation, which may be the reason for the problem...

No, this does not matter, there is no difference in how many times SkeletonAnimation.Update would be called.

Init

Harald
Sorry, my previous statement was incorrect. The actual situation is:

Each character has at least 7 Spine animations.
The maximum number of characters on screen can exceed 300,
while under normal conditions it's around 100.

So it results in 300 × 7 = 2100 and 100 × 7 = 700.

Init

Init During testing, I randomly created 300 characters and added as many components as possible to each character.

Harald

Init Each character has at least 7 Spine animations.

Oh, by "Spine animations" you mean 7 SkeletonAnimation GameObjects? I thought you mean that each character is a single skeleton and has 7 animations playing at the same time on 7 tracks. Machine translation might have mistranslated that for me earlier. Please note that in Spine terminology an "animation" is something like idle, walk, attack, etc. The proper term then would be "skeleton" or "SkeletonAnimation" GameObject.

Why are you using 7 separate skeletons for each character? While I don't know your reason yet, in general it should be much more efficient if you could combine them to a single skeleton.

Init

Harald

The reason is this: characters carry weapons, clothing, hats, shoes, bracers, masks, accessories, visual effects, etc., with many variants in each category. To support on-demand loading, we turned each of these into an individual Spine skeletal animation object and a corresponding Unity prefab. As a result, a single character is actually a composition of multiple Spine animation objects. Since all animations are built as frame-by-frame sequences, I can’t fully leverage Spine’s bones, slots, and skins—something I find regrettable. It may also be due to my limited experience with Spine; I’m still learning and not yet familiar with some of its advanced workflows.

Harald

Init To support on-demand loading, we turned each of these into an individual Spine skeletal animation object and a corresponding Unity prefab

Note that you could have each item be a skin, and letting the on-demand loading functionality (see here) load the respective atlas pages when necessary, e.g. via Unity Addressables. This way you could have a single skeleton with one skin per item, and have on-demand loading cover loading automatically for you.

Init Since all animations are built as frame-by-frame sequences, I can’t fully leverage Spine’s bones, slots, and skins

What exactly do you mean by "built as frame-by-frame sequences", do you mean you export animations as still image sequences from the Spine Editor? Or do you mean that you're using image sequences at Sequence Region Attachments?

Admittedly I can't quite imagine yet how your 7 separate skeletons as frame-by-frame animation are overlaid to combine equipment items, like how this does not cause problems with depth ordering and the like. In general you could still use skins to attach different sequence attachments, even though that's a bit of an odd workflow.

Harald

No need to apolgize!

Init I have prepared the following video to explain how I make animations. In the video, the four images numbered 1, 2, 3, and 4 are a sequence of a single action.

Thanks for the clarification. Please note that if you are spacing the images of your image sequence out evenly, you could also use a Region Attachment and enable Sequence (see the documentation here). With sequence attachments, you can still key the frame number and offset the timepoint in the timeline accordingly. This should save you a lot of boilerplate setup work seen in your video.

Init . Since all animations are built as frame-by-frame sequences, I can’t fully leverage Spine’s bones, slots, and skins—something I find regrettable.

Regardless of your workflow, when using image sequences you could still utilize slots and skins normally. You could for example create skins for each item, and use different sequence attachments for each skin. Then via combining skins you should be able to equip your items while using a single skeleton, instead of having e.g. 7 separate skeletons for equipment items of a character. This should reduce the number of necessary update calls by a lot, and you also have the option to much more easily control draw order of attachments (equipment items) inside Spine per animation, instead of having to arrange draw order of 7 skeleton GameObjects.

If I misunderstood some of your project constraints, please do let me know.

Init

Harald
I'm very sorry for replying so late.
I have prepared the following video to explain how I make animations. In the video, the four images numbered 1, 2, 3, and 4 are a sequence of a single action. (I have an Excel sheet for action frames to automatically generate and export animation files using scripts. I'm using Spine here to demonstrate my approach of creating animations with image sequences.)

Regarding depth sorting: I've set up a grid with cells that are 30x40. When a character moves, they move from cell A to cell B. This means that a character at cell (0,0) and a character at cell (0,1) will have a 40-unit difference on the Y-axis in Unity's standard world coordinates. I've written a script that calculates the order in layer value based on the Y-axis value of a Transform component's world coordinates. This script also allows for a manual offset value to be added to the calculated result before assigning it to the SkeletonAnimation's order in layer. This solves the depth sorting issue and ensures there are no rendering problems.

Init

Harald Note that you could have each item be a skin, and letting the on-demand loading functionality (see here) load the respective atlas pages when necessary, e.g. via Unity Addressables. This way you could have a single skeleton with one skin per item, and have on-demand loading cover loading automatically for you.

我没注意到居然还有这个功能, 我计划在未来找个时间测一下

Init

Perfect support! Harald, thank you so much. I'm honored to have met official staff like you and your colleagues. Your patience and determination to solve my problem have astounded me! The creativity of the Spine team has also deeply impressed me. I've been using 3.8.99 for a project, but after seeing your suggestion, I tried 4.2.43, and my efficiency in creating sequence animations alone has increased several times over.

However, please forgive me as I can't quite imagine what you mentioned about

Harald You could for example create skins for each item

. I'm not an animator; I first came across Spine in school because I was drawn to Live2D. I wanted to add Live2D to my own game to make the characters more lively. When I was looking for a tool, Spine appeared and captivated me. After I started working, I immediately subscribed to the essential version and soon after upgraded to the professional version. However, due to work commitments, I haven't had the time to delve deeply into Spine, which is why I'm still only using it superficially. This has always been a regret of mine.

It's wonderful to have a tool like Spine.

Harald

@Init Thanks very much for your kind words! Glad to hear our suggestions were helpful.

Init However, please forgive me as I can't quite imagine what you mentioned about

Harald You could for example create skins for each item

You can check out the example scene Spine Examples/Other Examples/Mix and Match Skins. This scene and the respective "Mix and Match" Spine project (see the documentation page here) show how you can create a skin per equipment item, and then have multiple skins enabled by combining these skins to one (see the spine-unity documentation here). Skins in general are perhaps a complex topic to understand, but enable an efficient and powerful workflow. Thus it's absolutely worth the effort.

In general we highly recommend having an in-depth look at all the included example scenes that come with the spine-unity runtime, as these cover many common use-cases.

Init

Harald
Apologies, English is not my native language. I'm trying to use Gemini to translate from Chinese to English and then back to Chinese to check if the meaning is correct, and there were some errors in the previous response. I didn't mean that I'll never be able to understand the use of skins you mentioned, but rather that I can't yet visualize what it will look like once that functionality is implemented. I'll start looking closely at the example project as you suggested. Thank you again for your patient explanation!

抱歉, 英语并非我的母语, 我在尝试使用Gemini将中文翻译为英文再翻译回中文检查语义是否正确, 刚才的回复中有一些错误. 我并非是永远无法理解您说的关于皮肤的用法, 而是暂时无法想象到实现了您所说的功能后是一个什么状态, 我稍后会开始按照您的建议去仔细查看示例项目, 再次感谢您的耐心解答!
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Harald

@Init No problem, thanks for the clarification!