Keeping one point still while another one moves.

[Reindeer]

Hi, how would I accomplish the following task:
imagine I have a bird flying in a circle and holding a piece of string in its beak. I want one end of the string to rotate with the bird, of course. But I want the other end to stay fixed, as if it were nailed to the ground. The string is a simple stroke between two points.

Is there a way to 'freeze' the position of the point on the ground so that only the point in the bird's beak will be free to move? I'm imagining there could be some bone constriction that will cause that point to not move at all so that wherever I move the bird I don't have to bother keeping the point still, but I haven't found how yet.

[drumlug13]

Try binding the points of the end of the rope in the bird's beak to the bird and just leave the other end of the rope bound to nothing. You would have to use a control bone to move the bird around instead of moving the bird's layer.

[Reindeer]

Try binding the points of the end of the rope in the bird's beak to the bird and just leave the other end of the rope bound to nothing. You would have to use a control bone to move the bird around instead of moving the bird's layer.

Ok, that was very good advice! I had gotten as far figuring out I needed to bind the end of the string in the beak to the beak bone, but I hand't realised I was thereafter doing it really wrong by moving the whole bird Layer. Now, moving the bird via his Control Bone as you suggested, I'm getting very close to what I wanted.
The reason I was moving the Layer is because I had the bird flying on an oval path and as far as I know only layers can follow paths.
After reading your answer I re-animated the bird by manually moving the Control Bone along the path, so what I get is pretty much similar to what I had, except now the end of the string on the ground stays nice and still!

[Reindeer]

Is there a way to attach a bone to a path or does that only work with layers? Because it would be handy in a case like this.
While the bird circulates in the air I was having his flight become smaller and smaller simply by reducing the size of the oval path over time. Now that I've solved the string problem, I've had to give up the automatic flight reduction because the bone is manually animated and is thus not subject to the path anymore.
The nice thing about reducing the path is that the bird stayed the same size and just circulated more and more close to the center.

So I figure that being able to assign a path to a bone could also be a nice feature.

[drumlug13]

As far as I know there isn't a way for a bone to follow a path yet. There was a discussion going on for this topic a while back. It's a different situation but maybe you can get something out of their discussion of a dragon to help with the bird.

viewtopic.php?f=13&t=25930&p=145685&hil ... th#p145685

[hayasidist]

will this be useful for you? viewtopic.php?f=12&t=25384

[Reindeer]

Thank you, I've not been able to check this out yet but it sounds interesting! When the same problem comes up again, I'll try it.