Bones [or something] to 'follow' or 'chase' each other!

Archived Forums Questions & Answers
1

Hi all,
Ok, I’ll try to explain what I want to do!

I have a set of linked (in 3ds max then exported via fbx) bones. I want the first bone to chase about using some ai (I’m using UnitySteer for now), but now comes my question…

Can I get the other bones to follow the first, curving about as if on a path, like a snake or missile trail?

There obviously is no path, as the ai is directing the first (parent) bone. But left along with no solution, the other bones obviously just follow in a stiff straight line behind thier leader.

Edit: After looking about at other people trying to do similar things, I need to add, these bones will end up deforming a mesh, so they have to be bones. Any solutions that won’t work with bones are no good (I think?)

Any ideas would be great… many thanks

i really think you just have to carefully program that.

 –

a little more info please. Do you want it like snake literally where each one literally copies the moves of the top (i.e. if it's 5 meters behind the front bone it should be where the bone was 5 meters ago?) Thats how the snake game works. each block aims to be well really each block just aims to be where the block in front of it is. That creates a chain and so each block EVENTUALLY do everythng the leader did is that what you want?

 –

Thanks guys. You may be right sparkzbarca, because the bones are linked, this may be a problem. Here is a simple pic to show the basic idea. [8684-follow_bones.jpg|8684] (The blue line just shows where it has been, its not a set path)

 –

I'm starting to think physics is the answer? Hinge Joint looks interesting, going to give that a try.

 –

Character Joint gives some interesting results...

 –

1 Answer

1
2

I have it working!
Imagine a little snake or worm.

  1. Skinned model from max, unlinked bones (haven’t tried linked yet)
  2. Add RigidBody components to each bone (no gravity & ‘Is Kinematic’ = ticked for the first ‘Head’ bone)
  3. Add Hinge Joints to all but the head bone, link up.
  4. Move the head about, I’m using UnitySteer.

It looks a little crazy, I haven’t got all my axis sorted out (Max & Unity) and if you add any animation it overrides the physics (some kind of ordering problem maybe). I can do secondary movement on each bone with script.

I am confident I can get the axis of everything correct, but it will take a fair bit of trail & error.

But basically a skinned model with bones, moving about using RigidBody & Joints!