Parenting an object to a bone

Hi,

I’m trying to make a control stick for an airplane. Between the stick and the floor there is a sort of fabric “sleeve” that bends when moving the control stick, like shown in this test model:


Now, I would like the stick itself to follow the upper bone in the armature, but since the stick doesn’t deform, I don’t want to skin it. (In this test model, it is skinned with all influences set to 1).

Ideally, I would like the stick to be parented directly to the “stick_bone”, but haven’t been able to find a way to do this.

I know I can do this with constraints, but I need to export it (through Collada) to a game engine that doesn’t support constraints, so I need everything to be keyframed transforms. I can link animation channels in the engine, but it would be better if I could do this hierarchically so that the stick follows the bone automatically.

Any suggestions?

Cheers,
Thomas

not a problem… skin the rubber boot part… as normal… using Ctrl+P then automatic weights…

but with the stick…
set your Armature to pose mode… then select your stick in object mode… shift select the ‘stick bone’ (the bone you want control the stick) then Ctrl+P (as normal) but then … select “Bone” … Not automatic weights or anything else…

that will directly Parent your stick object to that individual bone in the Armature…

so again…
Armature in pose mode
Stick in Object mode
Select Stick…
Shift Select individual bone…
Ctrl+P > “Bone”

Great, thanks! This method works, but for some reason the stick is rotated 90 degrees when exported through Collada into my engine. The stick sleeve moves correctly. The stick cylinder also moves correctly, but rotated 90 degrees relative to the bone.

I am pretty sure I have applied all object transforms.I have also tried the “Bone Relative” binding option, but that didn’t help.

It could be some issue in the Collada importer (I’m using Assimp), but it may also be that I’m doing it wrong… any ideas?

wow… you may have to post a file for me to figure that one out…

Here is a model that illustrates the problem. It has two bones, one for x rotation and one for y rotation, and the stick is parented to the y bone. It also has an animation on both these bones. It works nicely in Blender, but when I export it through Collada, the stick is rotated 90 degrees, at least when using the Assimp collada importer (http://assimp.sourceforge.net/)

https://dl.dropboxusercontent.com/u/8394167/stick_test_skinned_anim.blend

I don’t know about any other Collada importers that support both bones and animations, so I haven’t been able to test it with other software.

do me a favor and post your blend file via… pastall.org

http://www.pasteall.org/

they have a special place to post blend files on that site…
it makes downloading blend files from there nice and easy…

(watch for a the blender button over on the right had side)

Sure :slight_smile:

http://www.pasteall.org/blend/32256

hummm… looks like you have the bones working right…

deformation looks good to me…

not sure what’s up with the Collada part of the problem… I haven’t messed much with that preticular import/exporter…

Sorry…