Bone function needed for blenderpeople

Coding Python Support
1

Does anyone have a function, or could post one that does the following?

Given an armature, a bone, an action and a framenumber it will return the local space matrix of the bone for the given action and frame number?

def getBoneLocalSpaceMatrixAtFrame(armature, bone, action, frameNumber):

return boneLocalSpaceMatrix

Harkyman needs such a function in order to continue working on his blenderpeople stuff.

Thanks,

LetterRip

2 
def getBoneLocalSpaceMatrixAtFrame(armature_obj, bone, action, frameNumber):
      Blender.Set('curframe', frame)
      act = Blender.Armature.NLA.CopyAction(action)
      act.setActive(armature_obj)
      boneLocalSpaceMatrix=bone.getRestMatrix('bonespace')
      return boneLocalSpaceMatrix

…I think this works …maybe :-?

Ben

3

Hi Ben,

Here is a test blend and script

http://wiki.blender.org/pub/Blenderdev/SculpMesh/testbonematrix.blend

what I think needs to happen is that all of the matrixes from the root bone to the target bone need to be multiplied.

LetterRip

4

hmm would this be it?


def getBoneLocalSpaceMatrixAtFrame(armature_obj, bone, action, frameNumber):
      Blender.Set('curframe', frameNumber)
      act = Blender.Armature.NLA.CopyAction(action)
      act.setActive(armature_obj)
      boneLocalSpaceMatrix=bone.getRestMatrix('bonespace')
      if bone.hasParent():
	     boneLocalSpaceMatrix *= getBoneLocalSpaceMatrixAtFrame(armature_obj, bone.getParent(), action, frameNumber)
      return boneLocalSpaceMatrix
5

…if you want the distance of the bone from root
can use the :

bone.getRestMatrix()

without the (‘bonespace’).The defalt is (’‘worldspace’)

Ben

6

Yeah figured that out last night,

thanks though.

It is also mislabeled, since that is the objects localspace, not worldspace coordinates.

LetterRip