यह साइट एक आधुनिक ब्राउज़र में सबसे अच्छी तरह से देखी जा सकती है जिसमें जावास्क्रिप्ट सक्षम है।

NullReferenceException in Spine.Unity.MeshGenerator.AddSubmesh

ddddddddddd

Unity Version: 2022.3.20f1
Spine Version: 4.2-2024-12-20
Spine URP Shaders Version: 4.2.39

I created a dash animation for characters, where the alpha value is adjusted to 0 after the dash starts and then restored to 1 shortly after, creating an effect where the character disappears and reappears.

However, with some characters, the following error message is displayed every frame whenever the alpha value is adjusted. (The animations were made in almost the same way for all characters, but some characters don’t have this issue, making it even more confusing.)

NullReferenceException: Object reference not set to an instance of an object
Spine.Unity.MeshGenerator.AddSubmesh (Spine.Unity.SubmeshInstruction instruction, System.Boolean updateTriangles) (at Assets/Spine/Runtime/spine-unity/Mesh Generation/MeshGenerator.cs:576)
Spine.Unity.SkeletonRenderer.LateUpdateMesh () (at Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs:628)
Spine.Unity.SkeletonRenderer.LateUpdate () (at Assets/Spine/Runtime/spine-unity/Components/SkeletonRenderer.cs:589)
Spine.Unity.SkeletonAnimation.LateUpdate () (at Assets/Spine/Runtime/spine-unity/Components/SkeletonAnimation.cs:291)

The animation itself works fine, but the error messages are very distracting, so I’d like to resolve this issue. What could be causing it?

Misaki

ddddddddddd This is not related to your question, but since you have chosen the "International" tag, feel free to post in your native language if English is not your first language.

Our Unity expert Harald is currently on vacation, so it will take him some time to answer this question, but if possible, could you please create a minimal Unity project and email it to us so that we can reproduce the problem?:contact@esotericsoftware.com
It would be helpful to investigate the cause when he gets back.
Please include the URL of this forum thread in the email so we know the context. Then we can take a look at what's wrong.

ddddddddddd

프로젝트를 이메일로 제출했습니다.

새 프로젝트를 만들어 테스트를 해보다가, 'Use single submesh' 옵션을 활성화했을때만 이 문제가 발생하는 것을 확인했습니다. 머테리얼을 여러 개 사용할 것이 아니라면 이 옵션을 활용해서 최적화에 이점을 가져올 수 있다고 알고 있는데, 이 옵션에 최적화에 영향을 주는 것이 맞는지, 맞다면 어떻게 지금 문제를 해결하는 게 좋을지 알려주시면 감사하겠습니다.

Misaki

ddddddddddd Thanks for sending us your Unity project files! I was able to confirm the problem, however, the package even included unnecessary files such as the Library folder, so if you are asked to send us a minimal Unity project again in the future, please remove them before sending it to us.

It seems that the skeleton that is causing the error is using a clipping attachment, so if you enable the Use single submesh option of the SkeletonAnimation component in this state and do an alpha animation, it seems that the runtime tries to add a submesh and causes the error as it is prohibited by the option. In the case of your skeleton, it looked like you could adjust the mesh hull without using clipping so that the hair would not stick out of the hood, so you might want to try removing the clipping attachment. In fact, clipping in the Spine Runtimes is implemented using the CPU can be a very expensive operation, so it is better to avoid using it as much as possible in cases where it can be avoided.

Unfortunately, I am not sure why adding a submesh is necessary when using clipping and alpha animation at the same time, so perhaps Harald will explain this when he returns.

ddddddddddd

답변 감사드립니다. 다음에 프로젝트를 전송할 일이 생기면 꼭 해당 조치를 하도록 하겠습니다.

clipping attachment가 비싼 작업이라면, 혹시 이를 쉽게 대체할 수 있는 방법은 원본 리소스 자체를 조정하는 것 외에는 없을까요? 동시에 등장하는 캐릭터 수가 많은 편이기 때문에 되도록이면 최대한 최적화가 되었으면 합니다.

Misaki

ddddddddddd By the original resource you refer to, do you mean the images used by the skeleton? At least for the skeleton included in the data you provided, it seemed that the image did not need to be changed, only the mesh hulls could be modified.

Based on your information that there are many characters appearing in the scene at the same time, it is actually best to avoid using clipping attachments. However, if it is necessary, you can improve performance by setting the clipping attachment to be active only when you need to use it, rather than leaving it active all the time. For example, clipping attachments are often used to create blink animations, but even in this case, it is a good idea to keep the clipping attachment inactive while the eyes are open and activate it only when the eyelids are down.

ddddddddddd

답변 감사드립니다. 이미지를 말씀드린 것이 맞습니다. 최적화를 위해서는 clipping attachment를 사용하기보다는 이미지를 잘라내는 쪽으로 수정하는 쪽이 낫겠네요.

여러가지 고려 사항이 많겠지만, 모바일 환경에서 한 화면에 동시에 등장하는 최대 캐릭터 수를 일반적으로 몇 명 정도로 생각하면 좋을까요? 정확한 수치가 아니더라도 참고할 수 있을만한 값이 있으면 좋을 것 같습니다.

Misaki

ddddddddddd Unfortunately, it is difficult to answer the question about the maximum number of characters, since it depends on various factors, such as how complex the skeleton is and the resolution of the skeleton's textures. However, some users have in the past posted the results of their tests displaying a large number of skeletons, so you may want to look for such threads in this forum. For example, the following thread may be helpful:
https://esotericsoftware.com/forum/d/15046-performance-analysis-of-mecanim-vs-animation