Excellent work here! I really love good strata maps, they add so much to an image.
As to the Terragen debate, my feeling on it is that while it may not be as powerful and versatile as larger rendering/modeling packages, that’s mainly because it’s built solely to do one thing, and do it well. So no, I can’t make a character model in Terragen. I can’t make anything, really, but a landscape - but that’s ok because most of the time, that’s really all I want to do anyway.
I also really like Terragen because the learning curve is very distributed. The beginner can start up the program and not be utterly overwhelmed by the complexity of the interface and the countless buttons and windows that, say, MAX and Maya are comprised of. In terragen, you can start as simply as you like, and with practice slowly become more adept at managing the advanced options - there’s as much depth there as you need, but you don’t need to see it unless you want to.
I myself tend to view my own Terragen work as a kind of photography - except of course that you now have control over every aspect of the shot, instead of being subject to the bounds that nature imposes on me. I spend days working on images, and I think the work I put into them shows in the final product. I make all of my texture-maps by hand now, and I use World Machine’s amazing “flowchart” interface to tailor-design my terrains to my own (somewhat exacting) specifications. I also design every aspect of the atmosphere myself. I could let Terragen do all of that for me, but I’ve moved well beyond the stage where I feel I need to - I get much better results on my own anyway.
In short, that’s the beauty of Terragen. It starts you off simply, and you can progress as far as you like from there, instead of dropping you into the deep-end headfirst like my attempts with Max and Maya have felt like. Who learns to ride a bike without training wheels, anyway?