I really don't think it's anywhere as simple as you seem to think, but I don't think that's necessarily a problem. If you can managed to get a workable 3-D engine into Simutrans, I'd be happy with that.
I wouldn't be surprised if you don't find much in the way of coding help here, though - we're a pretty small community, and most everyone who can work on things is already spending their free time doing so. So if you make calls of "help me!" and very few respond, if doesn't mean everyone hates the idea; I think it means more than everyone who can do, is already doing.