We have an answer!

Dont have time to capture and post it now... But James (the coworker with the original task) has found a way around the Theta Constraint problem...

Can you say "arc sin"....?

Trig family Broken.... :(

As much as i harp on my constituients to always "Flex them before you load them," i have evidently been a victim of not practicing what i preach. Something isnt working right in the below mentioned family... Any input on this? Im a little heartbroken :(

As you can see, everything flexes perfectly, including the Reference Lines that need to define the angle/paremeter "Theta." However... Once we actually place the Label for Theta, the reference lines become locked in at that angle, and no longer flex with the rest of the family. See below:

It is trying to hold Theta, instead of holding the constraints to the Reference Plane intersections where i have set up the reference lines. So far, ive tried a few workarounds on this, but havent gotten it to perform the way i thought it was...

So were past the hard math, now its back to pesky Revit Constraint headaches! :)

Shoot me an email or a comment if you have any ideas on the matter. Things ive already tried to circumvent:

An itermediate Reference line, dividing theta by 2, in to thetaby2, and constraining those. (Creating an angled EQ toggle). Didnt work, held them even, and held them constant. :(

Nesting the family in to another family, and trying to get Theta in the nested family. Once i constrained ref lines in the parent family, it wouldnt let it flex at all. Owned.

Deriving Theta mathematically and not tying it to the reference lines at all: Circular chain of references. I need theta to derive the arc length, and need the arc length to derive theta.

Freakin constraints! Someone help my wounded pride!