How do I get an object to stretch between two animated objects?

Question

I want to animate this LEGO x-wing closing its wings, and have managed to rig up bones to control the wings so they close on the correct rotation, but it has this elastic band on the back that needs to be on those two black pieces and stretch between them when the wings open and close. How to I do that?

I'm thinking weight painting is involved? Do I make a bone on each black piece?

I'm only new to blender only this year so please explain as basic level as possible please! Many thanks in advance!

Answer 1

I can suggest two options:

1. if you want to use it in 3d engines (with only bones animation), you can use two bone system:

   • One bone at one black thing and weight paint it (gradient) to the parallel part of the rubber mesh.
   • Second bone at the other black part
   • attach "track to" modifier to the first bone with target as second bone.

2. Make a "Shape Key" of the rubber with stretched pose, and move and rotate as required. You can also use both (1 & 2) for easy animation and right mesh deformation.

Answer 2

Figured it out. Thanks for the help @user105387.

1) add one bone at each of the four black pieces. (snap your cursor to the active element then add armature to be exact)

2) select the rubber band and also select the upper bone. Go into pose mode, parent the rubber band to the upper bone with automatic weights. when you move the upper bone in pose mode the rubber band should move with it. when you move the lower bone the rubber band should move too.

3) parent the bone for each black piece to the corresponding bone you made on each wing. That will make the band bone move when you move the wing bone.

4) select a bone nearby, then the rubber band, go into weight paint mode and make sure the band is all blue for those bones so it's not influenced by any other bones than the ones on the black pieces.

5) you can now create a pose and if they're all parented correctly it should work.