Bug report: VRM1 has bone problems when importing

[Applepiee]

Describe the bug

When importing a VRM1 model, many bones are placed in the wrong position or are not connected when they should be. And the eyes also have a completely different position and are always rolled (it shouldnt be rolled as it gives problem in some look animations).
When I try to import the VRM1 model direct into unity, everything is fine. But if I import a VRM1 model that has been exported with blender, then many things are broken (mostly the eyes when I use my eye animator script)

To Reproduce

Import any VRM1 model (Latest Steam VRoid Studio)

Expected behavior

Normal bone structure

Screenshots

Desktop (please complete the following information)

• OS: Windows
• Blender 4.0
• Addon Version: 2.20.86

[saturday06]

Because VRM 0.0 did not include “bone orientation”, it was possible for add-ons to connect bones as they saw fit.
However, this is no longer possible with VRM 1.0, because “bone orientation” is now included in the data. If the add-on specifies the bone orientation as it sees fit, it will ignore the creator's intentions.

[saturday06]

When using Unity to correctly handle VRM1.0 eyes, please be sure to keep the following points in mind

• Please use UniVRM version v0.116.0 or later.
• When loading a scene in UniVRM, please make sure that the model is facing the +Z direction. Do not rotate the model.

In addition, the processing of eyes in Unity is very difficult to handle, and there are many points to be careful of. Please refer to the related issues in the UniVRM repository.

• [初期姿勢] Awake で Transform から収集するのではなく VRM など元データから直接伝搬させる vrm-c/UniVRM#2427
• [1.0] LookAtTarget does not work correctly if a character isn't facing +Z at scene start (+ fix?) vrm-c/UniVRM#2345
• LookAt works within Unity, when exported one eye has mirrored movement vrm-c/UniVRM#2335
• 目のボーンに回転が入っているVRM1.0ファイルがLookAtTargetの方向に向かないことがある vrm-c/UniVRM#2159
• VRM1: VRMが無回転でない状態でシーンに配置されたとき、LookAtの挙動がおかしい vrm-c/UniVRM#2106