As we've discussed in previous threads, there are a number of things which make Terragen's images look the way they look.

1. No perceived sense of scale. Because of the nature of the rendering engine, and the lack of other objects in a scene (until TG2), there is no sense of scale in an image. In fact, with TG2, now that one can put in a tree or forest, the realism is certainly less with 'other' objects inserted than before. With no sense of scale, there is lessto 'throw the eye off' that an image is not real. This picture demonstrates the effect:

2. Terragen's superior fractals. Terragen has a super grainy fractal which works great for stills, but wreaks havoc when trying to do an animation. Of course, with TG's rendertimes and lack (to my knowledge) of a network renderer, few an actually can do any animation. With the two new fractals David mention above, Vue 7 can now do the same. If I wasn't bogged down in work right now, I feel positive I could create very similar results to Terragen renders.

On a side note, Vue's fractal terrains aren't as good as GeoControl. Many times you can get nice results from importing a TG terrain directly into Vue. Not hard to do-- search this forum and you'll quickly find the recipe.