How to make fully parametric models that change in-game?

I want to make models for my game based off a set of parameters. I want the model to be completely from the parameters without creating a model in a standard modeling program and changing it with parameters.
The parameters will change in game so the creation will constantly be changing. I’ve looked at different modeling techniques, but I don’t know if I could use them.
For instance this document link on page 3 shows a similar type of modeling based on polygon mesh changing off the set of data. They also mention that using Metaballs or Constructive Solid Geometry would also work. I’ve looked at techniques like sweeping, turtle geometry in Elicia, zSpheres, and the language Hyperfun.
However I don’t know which is ideal, or how to implement them. How would I go about making parameterized models? Will I have to create some new type of modeling format or converter to get the results I want, or is there something that would work?