Hi,
Using quad meshes to represent sprites, I’m attaching different pieces to the actor body to compose it.
When attaching a quad mesh to the parent body, the bone is not following the rotation of the parent.
Am I doing something wrong here?
https://playground.babylonjs.com/#YM8MSS#3 You forgot to link bone - mesh. Not sure if it should rotate like that?
N.B. I could have sworn that you can set it up in a way where you can transform the bones directly.
N.B.2: Keep in mind that there is “vertex weights” which you are not dealingh with here at all. So there probably is some more work to do.
2 Likes
Now it rotates, but… the rotation is not according to the parent.
Hello 
I think your problem comes from the fact that you have no root bone.
Try this :
const boneROOT = new BABYLON.Bone('bone', quadMesh1.skeleton, null, BABYLON.Matrix.Identity());
const bone = new BABYLON.Bone('bone', quadMesh1.skeleton, boneROOT, BABYLON.Matrix.Identity());
2 Likes
That is!! Thanks so much!
1 Like
Why? The original PG does have a root bone (see Inspector).
Might there be a bug if the skeleton only has a single bone? attachToBone looks innocent though 
Maybe here: if attachToBone was called, this path is taken in computeWorldMatrix. But then I get lost because bone._finalMatrix is never updated 
Yes, but here @Khanon wants to move a bone and attach a mesh to it, and in that case it should not be the root bone, I guess. I don’t have the exact answer to the “why ?” but I just notice that either BabylonJS or Blender, it’s always like so : root bone, and then you attach some transform bones to it . I guess it’s a matter of hierarchy organisation / convention or something like that
1 Like
For some reason this is not working in my engine 
I’m investigating but the structure seems to be the same than the PG.
PS: Ok, I found it, the problem is using billboardMode in the hat mesh, which is attached to the bone.
@Evgeni_Popov some idea if this is the desired behaviour or a bug?
1 Like
I think it’s the expected behavior, but you can try to set TransformNode.BillboardUseParentOrientation = true and see if it fixes it.
1 Like
Yes, that works, anyway I’m unsetting the billboardMode for the child.