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BoneIKController and bone orientation


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In Babylonejs, BoneIKController assumes that all bones are oriented along the x-axis, like the Dude example http://www.babylonjs-playground.com/#1EVNNB#15

I find that "The bones should be oriented along the y-axis". Here is the demo of using BoneIKController with y-axis http://www.babylonjs-playground.com/#1EVNNB#46. To make it work correctly, you need to change

BABYLON.Matrix.RotationYawPitchRollToRef(0, 0, Math.PI * .5, mat2);


BABYLON.Matrix.RotationYawPitchRollToRef(0, 0, 0, mat2);

in babylon.boneIKController.ts file. 

Of course, we can't expect that not all bones follow the same convention. So I wonder

  1. Will it be solved by adding {adjustYaw, adjustPitch, adjustRoll} option like BoneLookController?
  2. Is it possible to detect the bone orientation automatically?

Or we just add bone orientation parameter to BoneIKController. 

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On 2/12/2017 at 7:40 AM, shen said:

In Babylonejs, BoneIKController assumes that all bones are oriented along the x-axis, like the Dude example http://www.babylonjs-playground.com/#1EVNNB#15.

Here is a demo with a simple model that was created in Blender that has bones oriented along the y-axis:


Please post an example that demonstrates the issue you're having.  You might just need to change the bendAxis.

In this example, the second bone is bending on the z axis:


I might need to improve the way the default bend axis is set if it isn't set by the user.



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I might not describe it clearly. I'm talking about how to make the bone point to the target (no the default bend axis). 

For your 2 examples, y-axis always point to the target mesh (with or without bendAxis option), seems because BoneIKController._rightHandedSystem is false. 

For my example http://www.babylonjs-playground.com/#1EVNNB%2346 and the dude demo http://www.babylonjs-playground.com/#1EVNNB%2315 (both _rightHandedSystem = true), x-axis always point to the target mesh. I can make them work with y-axis by setting BoneIKController._rightHandedSystem to false (It will cause another problem with bending). Is it Babylonjs' problem or the meshes' error?

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