How to set world rotation for a transformNode with multiple hierarchy nodes?

Questions
1

Hi everyone, a gltf file has numbers of node , and some meshes inside transformNodes. One of those i want to set it to one world rotation. That mesh has parent, and the parent has parent…
I think it need to set world rotation zero first, then Mesh.rotation = WorldRotation. How can i solve it?

2

Assuming the mesh you want to set rotation starts with (0, 0, 0), if not you would need to add the rotation offset.

First you can get absoluteRotation as Quaternion:

var worldRotationQuat = mesh.absoluteRotationQuaternion

Now you can convert to euler angles (rotation-Vector3):

var worldRotation = worldRotationQuat.toEulerAngles()

Then set rotation of mesh to your calculated rotation difference/delta:

var wantedRotation = ... // set your wanted world rotation
mesh.rotation = wantedRotation.subtract(worldRotation) // local rotation

It would also work to multiply worldRotationQuat.invert() onto BABYLON.Quaternion.FromEulerVector(wantedRotation). Then convert back to euler vector.

Or do this via world matrix of mesh and TransformNormal, when you are into the math, to localize wanted rotation:

4 Likes
3

Thanks @Takemura , i had solved the case in my project by your answer :smiley:

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