Adding spine stretch

- Now let's take a look at how to add…a little bit more realistic squash and stretch to the spine.…Now we have these controls here…and they can stretch the spine,…but it's not really all that realistic.…We don't have any scaling going in the opposite direction.…So we can do this using a number of methods.…We're going to take a look at how to use set driven keys.…This is probably a lot easier than…the expressions and nodes that we looked at last…but they can be just as effective.…So let's start off by taking a look at these controllers.…

The first thing is that, well,…the numbers are a little bit off.…So we need to make sure that these all reset to zero…so that way it's easy to manipulate this.…So the first thing I'm going to do…is I'm just going to do a…freeze transformations on each of these.…And what that does is it just makes sure…that each of these is zeroed out.…So now that I have that, I can start working.…Now what I want to do is I want to take…this joint and I want to scale it so when it goes up,…I want to scale it along this axis which is y.…