[Bf-python] Making IK flag writable in the Bone class

[Jonas Petersen]

Gilbert, Joseph schrieb:

>Yes ic your point, but does the bone become enlongated when this
>happens?
>  
>
Yes it does.

>-----Original Message-----
>From: bf-python-bounces at projects.blender.org
>[mailto:bf-python-bounces at projects.blender.org] On Behalf Of Jonas
>Petersen
>Sent: Friday, October 22, 2004 1:10 PM
>To: Blender Foundation Python list
>Subject: Re: [Bf-python] Making IK flag writable in the Bone class
>
>Gilbert, Joseph schrieb:
>
>  
>
>>There is more to it than that. The reason that setIK was not
>>    
>>
>implemented
>  
>
>>was that once the flag is set the matrix of each bone must be
>>recalculated so that the head becomes attached to the tail of the
>>preceeding bone. You will be able to set the flag but it's basically
>>meaningless without the recalculation of the parent/child bone
>>    
>>
>matrices.
>  
>
>> 
>>
>>    
>>
>Yea you're right. I investigated the issue. But as far as I can tell no 
>matrix has to be recalculated. Only the head position of the affected 
>bone has to get adjusted to the position of the parents tail. This is 
>done easily by just setting its position to (0,0,0) because its relative
>
>to the parents tail anyway.
>
>I python it could be done like this:
>
>  bone.hasIK(True)
>  bone.setHead(0,0,0)
>
>Btw. you can mess up the head of an IK'ed bone the same way:
>
>  bone_with_ik.setHead(1,1,1)
>
>This is not taken care of neither. Though it will correct itself 
>automatically as soon the joint will be moved.
>
>But of course this is no excuse. So I modified the function further that
>
>it...
>
>...will not set IK if affected bone has no parent.
>...adjust head of affected bone.
>
>I implemented and tested it positively.
>
>What do you think?
>
>Regards,
>Jonas
>
>  
>
>>-----Original Message-----
>>From: bf-python-bounces at projects.blender.org
>>[mailto:bf-python-bounces at projects.blender.org] On Behalf Of Jonas
>>Petersen
>>Sent: Friday, October 22, 2004 8:10 AM
>>To: bf-python at projects.blender.org
>>Subject: [Bf-python] Making IK flag writable in the Bone class
>>
>>Hi everybody!
>>
>>I hope this ist the right place to post this...
>>
>>The IK flag in the Bone python class is read only. The only way to 
>>modify it is the corresponding button in the buttons panel. It's not 
>>possible via python.
>>
>>I modified  python/api2_2x/Bone.c so the flag can be modified via
>>python.
>>
>>For now I did it by adding an optional bool parameter to the hasIK() 
>>function that sets/unsets the flag.
>>
>>An alternative or additional way would be to make the IK class member 
>>variable writeable.
>>
>>What do you think?
>>
>>I could supply a patch if desired.
>>
>>Regards,
>>Jonas
>>
>> 
>>
>>    
>>