I'm trying to create a rectangle that boxes in a spline

[Anonymous]

I'm trying to create a rectangle that boxes in a spline sketch. I'm essentially trying to create a boxing system which may involve some python coding, but not sure. What I would like is a rectangle that remains tangent to my object in a given plane in order to keep track of measurements. If anyone can point me in the right direction, I'd be very much obliged. 

As an aside whenever I try to make a rectangle and use the tangent constraint it gives me an error that it is over-constrained.

[mavigogun]

Could you provide an illustration of what you need to achieve with state variations?

[Anonymous]

After researching further, it seems I am able to achieve the desired ability using a "transient bounding box."

In my industry, I need to create novel shapes within a given set of parameters, in my case a box. We actually call it a boxing system. So, what I'm trying to do is to have an overlay of the information I need when working with shapes so that I know I haven't exceeded my limits. These shapes are based upon human features and getting my shapes within the box as close as possible will allow me to prototype better.

I've tried using different splines and the rectangles won't snap or constrain to the spline. I don't actually need the rectangle just the XY dimensions. I am now looking to use a coded method for me to get the tangents of my splines. Any advice or instruction is welcome. I also need to learn how to pass a user selection to some code for processing.

[davebYYPCU]

You may find, toggling the rectangle dimensions to driven, with right click menu when dimensioning, will get you there,

as the rectangle comes before the spline, you can click - drag the rectangle legs until you see the required dimension.

Might help....

[Anonymous]

Where would I find that? I've never seen that feature before.

Thank you for taking the time to answer.

[davebYYPCU]

Dimension Tool, 

select the article/s to dimension,

before placing the dimension, right click,

select Driven, from that menu,

then place the dimension.

Might help....

[Anonymous]

Thank you all very much. I learned something new regarding that driven dimension option, which is pretty cool. It looks like I do need to code this though through a bounding box (via python) as the driven option only works for Fusion's predefined objects. That said, I appreciate all of the responses thus far as I do use predefined objects a lot.