Does UE4 Contain a Data Structure Suited To Storing Phase Diagrams?

I’m looking to use this in c++ but I’m guessing if it exists it would be in the format of some kind of animation helper I might repurpose for this task.

What I’m looking for is a data structure which can contain (and ideally match an x/y coordinate in it to a given item, assuming each section is itemized) phase diagrams like the following:

Just want to make sure I’m not reinventing the wheel before putting something together (realistically I’d probably look at it as polygons spread over x/y coordinates and doing hit testing, but if there’s a nice GUI-based way to put those or a similar structure together in UE4 that would be ideal.

I would use a texture for this or as you suggest use and actual geometry and find ray triangle intersection.
In case of texture, the problem will be discretization and necessity for non-linear sampling as specifically phase transition is non-linear.
With geometry the problem is just how would you store your function? You could bake it into vertices but then again you need some non-linear interpolation for it.
If you care about good precision something like large lookup table could be used.