Getting position & rotation in parent space
<p>I have few bones.</p>

<p><code>Bone001</code>:</p>

<p><a href="https://i.stack.imgur.com/O782s.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/O782s.jpg" alt="enter image description here"></a></p>

<p><code>Bone002</code>:</p>

<p><a href="https://i.stack.imgur.com/fc0Tr.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fc0Tr.jpg" alt="enter image description here"></a></p>

<p>The are aligned in the same direction. <code>Bone001</code> has an rotation (in both World and Parent space). <code>Bone002</code> has the same rotation as <code>Bone001</code> <strong>in World space</strong> and it's rotation in Parent space (<code>Boone001</code>) is <code>0</code>.</p>

<p>I want to get the position and rotation of <code>Bone002</code> in Parent space (which should be <code>0</code>).</p>

<p>I have tried (according to <a href="http://help.autodesk.com/view/3DSMAX/2016/ENU/?guid=__files_GUID_6C7219CF_B9B7_4B18_A846_5522A9D970F3_htm" rel="nofollow noreferrer">official documentation</a>):</p>

<pre><code>--each and every returns the same World space pos (as $Bone002.transform.pos)
(in coordsys parent $Bone002.transform.pos)
(in coordsys local $Bone002.transform.pos)
(in coordsys $Bone001 $Bone002.transform.pos)
$Bone002.transform.pos *= inverse $Bone002.transform
</code></pre>

<p>But each and every of them returns the <code>Bone002</code> World space position (and not the Parent space one). Same for rotation.</p>