Detail 2 takes a LOT longer to render and adds virtually no discernable detail to the end result (output image). As you can see, the slider only goes up to 0.8, there's a reason for this. Terragen allows you to manually set almost any crazy value you want for every setting, this is part of its power and flexibility, but that doesn't mean that doing so will have any benefit, and in fact often times going outside the slider ranges (the generally recommended values) will produce "bad" results (it seldom crashes, but often increases render time without benefit, for example).
Cranking up the detail is really not the way to get "super HD looking pictures". Just like buying an expensive, high megapixel count digital camera won't give you great-looking photos! The *biggest* contributor to the quality of the final images is the quality and detail of the *scene construction*. Putting lots of care and attention into creating detailed terrains with lots of fine displacement (but balanced with smoothness, not *just* "fine displacement" everywhere), making subtly varied and complex surface maps, finely tuning your cloud shapes, density, etc. and your atmosphere settings, using high quality plant models and adjusting population variation and other settings carefully, etc, etc. Increasing quality only increases the "accuracy" with which Terragen evaluates what *you* put into the scene. You need to put a good amount of time and work into any scene to create a quality end result.
To give you a clear example of how this works, think about this: you can load up the default scene and turn detail to 10 and AA to 32 and render it, and it will still look plain, boring, ugly even; turning up detail only makes *what is already there* look better. At the same time, if you load up one of the nice example scenes included with TG3 and render it at, say, 0.25 detail, AA3, it still looks pretty good! Yes, it could look better with higher detail, but *most* of the sense of realism and quality comes from the scene construction itself, not the detail settings. Examples are attached.
First, you have the base scene, rendered at defaults, 0.5 detail, AA3, render time was a mere 49 seconds. Then the same base scene at Detail 2, AA16, render time was 17 minutes, 51 seconds! As you can see there is virtually no difference, certainly nothing to justify the huge increase in render time (flipping back and forth I actually prefer the lower detail version in some respects, though again the difference is minor, and certainly subjective). Finally, we have a scene included in the TG3 content bundle called "example_high_complexity_scene.tgd", rendered at detail 0.25, AA3 (purposely below the defaults to emphasize that scene quality matters more than detail levels). Render time for this was only 1 minute, 11 seconds, but while you certainly *notice* that it's at a lower detail, I think it's clear that the scene is of high quality, and simply turning up quality moderately, even to 0.5 detail and AA4 shows that the end result improves markedly, which is shown in the next image, render time was 2 minutes, 49 seconds. Rendering it at detail 1 took nearly 10 minutes and looked only marginally different, much less of an improvement than with 0.25 to 0.5.
This is obviously an extreme example since the default scene is very simple, but I think it actually illustrates the point very well when you look at the comparison scene at low detail. Essentially, you get diminishing returns with higher and higher detail levels, and we really don't recommend above 0.8.All that being said, it's also possible that the "super HD quality" you're talking about is simply the result of some post processing work that has little to do with Terragen. I find this is often true in photography especially, where someone with the same camera, lens, and shooting position can get an entirely different (and much better) result in post processing because they know how to use their processing tools better. Many people use HDR/tonemapping on Terragen images (especially EXR output), or other "light tuning" type of operations, levels adjustments, sharpening, etc.
I would suggest actually that you post some links to images that have this quality you're trying to achieve. It's probably a mix of baseline scene construction quality and correct (not necessarily super high!) detail/quality settings (including AA, soft shadows, etc.), but hopefully it will help us point you in the right direction for achieving the results you want. But I must reiterate that there are no real shortcuts, it will inevitably take you time and work to improve your scenes to the high level of quality you probably want. There is a lot to learn.
- Oshyan
