[mk_stjames]

Every modern CAD tool like those commercial ones I have mentioned automatically track the paramaters as you build a model from scratch. They are parametric models by default. At any point you can go back and edit a number in the tree and the model will attempt to update as if you have used that value in the beginning. It's hard to explain this if you are not familiar with how those programs work.

I'm not talking magic here. What I'm saying is, I'd like the ability to read the model file as text outside the CAD package, and edit and compile (update) exportables in a scripting languge. Again, what I am saying is actually already the way many tools, like Catia and NX, etc work... but they lack an external API/callable module in an external language (Catia can be scripted with VB script, blegh.) And nothing that is FOSS.