Keep fixed distance

Artistic Support Animation and Rigging
1

Hello fellows Blenderer,
I need some help with constraints (I think). Here is the problem: I need that a cube would keep a fixed distance with a circle, cylinder or whatever you will say it is better for the task.

Forum
Forum1530×868 173 KB

Basically the green line has to be always the same dimension while the circle can scale giving the dimension to the cube around.

E.G: At dimension of the circle 2 the cube is 2.5 at dimension of the circle 3 the cube is 3.5

As you can see I can’t just copy scale because the dimension will scale proportionally not keeping the offset of .5 that I need.
I have good skills in Blender and I can work with empties, bones and a lot of stuff.

But on this I have no idea on how to do it…
Many thanks.

2

I would use a driver to ‘copy’ the scale. You can type math formulas there, so this is not a problem. You can say scale_cube = scale_circle+1.

Like this:

scale-driver.blend (487.9 KB)

3

Thanks a lot, it works like black magic! I am more skilled in modelling and animation.

Rigging, constrains and whatever is still a little mystery. If you know some good tutorial to learn the basics is really appreciated.
Thanks a lot