I've recently got really into playing Kerbal with the USI Modular Kolonization Systems mod, and had an idea for a small-scale add-on for that suite of mods. I have some background coding in Unity (although my grasp of C# is still a bit hesitant), and thought this would make a fun project to build my coding skills. I've been reading through a lot of the "how to get started" guides and have a rough idea of how to... well, get started, but before I start barking up the wrong tree, I thought I'd ask here for opinions on how best to approach designing and building the mod.
The core idea is to add structural parts that are affixed to the ground, like the ground pylon in the MKS mod (the one that is basically a launch clamp without the decoupler, rather than the KIS ones that are fixed to the ground on EVA), but using an "in-line" model rather than the radial surface-attached model. I know this needs three parts (the surface attachment, the vessel attachment, and a stretchy bit in between) and I think I can probably figure it out by pulling apart the stock models and the cfg file, I just wondered if there was any subtlety to it that I should be aware of before I start noodling with them? For example, would it need any custom .dll files?
The other arm of the project was that the structures should be initially deployed (using MKS Ground Construction, i.e. you establish a small workshop, ship out a DIY kit and build the structure in situ) as a part-built superstructure (i.e., all the metal bits), and in order to "finish" the structure, you import a large amount of local raw materials(e.g. ore, silicates, gypsum) and hit deploy. Basically, you're making the large amount of concrete needed to build the structure on site rather than abstracting it as "material kits" or the special parts int the DIY kit).
I don't really envision this being extremely complicated, but I might be missing something subtle. The idea would be to have two meshes for the part; when you're designing your base in the VAB you see the "complete" model (with, I expect, a button to preview the "incomplete" model), but when it is "launched" (either via Ground Construction or if for some bizarre reason you rolled it out of the VAB on Kerbin) it defaults to the "incomplete" model. Then, when you've accumulated the materials and hit "deploy", you get a puff of smoke and the model switches to the "complete" model (preferably without any way of toggling back to the incomplete version).
So my core question is, what's the best way to implement that kind of behaviour? Does any of that get baked into the .mu file, or should I be building a .dll that gets tied to the part?
Thoughts, comments and suggestions appreciated (including "this idea sucks" :P)