[Bf-python] Re: Python -- Orientatoin problems. (Ken Hughes)

[Kenney Phillis Jr]

I can sort of read the armature code.... which armature code are you 
talking about? ( python's plugin or the internal blender stuff )


1: initial roll is set via a rotation setup on the armature:
2: bones use the roll value to figure out the W value ( i think )
3: bones tend to be out of the object i embed em within the object that 
athey are parented to.

to see the 3 issue, just try export the values of the bones and recreate 
them with only the blender values of
bone position, orientation, lenght, parent, and  size information... the 
issue that is used... this thread was actually based off of my old bug 
report, here:
 http://projects.blender.org/tracker/index.php?func=detail&aid=2461&group_id=9&atid=125
( the script i used is the newer verson on my initial message )


Ken Hughes wrote:

>I think I found the problem for bug #2230, but can't think clearly enough
>to find a solution (if someone can read the armature code, please explain!).
>
>Looks like getRestMatrix() is relying on the bone's roll variable to calculate
>the rotation, but roll is always 0.  In most of the armature code I've read
>seems they calculate roll then reset to 0; can't see where it's being used.
>I put a printf in make_boneMatrixvr() -- called by Bone_getRestMatrix() --
>to print roll and it's always zero.
>
>Nick Lawson wrote:
>  
>
>>It could be related to
>>http://projects.blender.org/tracker/index.php?func=detail&aid=2230&group_id=
>>9&atid=125
>>
>>In which the quat and loc of bones is not outputting correctly via python,
>>even in 'bonespace'.
>>
>>-Nick
>>
>>
>>-----Original Message-----
>>From: bf-python-bounces at projects.blender.org
>>[mailto:bf-python-bounces at projects.blender.org] On Behalf Of Kenney Phillis
>>Jr
>>Sent: Monday, June 06, 2005 3:08 PM
>>To: bf-python at projects.blender.org
>>Subject: [Bf-python] Python -- Orientatoin problems.
>>
>>with most models i make the origin for the bones is off....
>>picture of the offset issue of blender: 
>>http://img65.echo.cx/img65/3514/offsetissue3ck.png
>>ik picture issue: http://img138.echo.cx/my.php?image=standardikoutput9nn.png
>>
>>the two images point out two different issues... you can look at my 
>>attached script for debugging purposes, but the issue is that the world 
>>space and bone space quats don't show negative values on rotation..
>>
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>>