Artisitc Merits

Great Scott!  So perfect, especially the mountain in the background.

Question: how much direct control do you have over placement: trees, shoreline, etc? How much of that picture is your choice?

{{Well it all starts with your terrain.
In this instance I used a particular type of fractal terrain called the Alpine fractal for the good reason I wanted Alpine style mountains.
Now that will generate a planet sized terrain based off the random seed and whatever individual settings you give it.

So for example here is the scale tab for the terrain-



To that there are adjustments in the displacement tab, this essentially displaces the surface, increase it and the surface will displace upwards, increase the roughness you will get more cracks, ledge and small features ect



Another powerful tab here is the Tweak Noise tab, this lets you change which type of fractal mathematics are used to generate the land, producing wildly different landscapes from the same seed and settings.



There are other ways to adjust how the land will look, you can use masks to have it only render your mountains in certain areas, or you could even plonk a heightfield fractal terrain on top of it as this will get priority over the original, but you can adjust the size of a heightfield to have it only cover the area you want- handy if say you want a small area of flattish ground in terrain that's otherwise very rocky and mountainous. So you can have quite a free hand to creating the sort of landscape you want.
If you take a look through the pictures Ive done you can get an idea of the variety of landscapes you can produce.

You can also if you want to have more direct sculpting control over it use a 3rd party program like World Builder which can import the terragen terrain files and let you make more fine tune adjustments to them.

When it comes to objects you have a great deal of control over placement.
Here is one of the tree populations highlighted that I used in the above picture-



On the right you can see a mini-map of how they will appear within the area length I have set for populating. On this tab you can set the spacing, how far apart form one another the objects are, set minimum and maximum sizes, set the siz eof area to cover and some other adjustments.
Note that it also has a distribution shader plugged into in the density shader tab- they are very handy.
Here's the distribution shader for that population-



It's on the slope constraints tab, as you can see I have set that the trees never grow on a slope more than 37.6 degrees. The altitude tab is also in use here setting the maximum altitude they will appear at, leaving the mountain tops clear of trees above the snow line, and also I set the minimum altitude to be just above the water altitude, preventing trees being rendered in the water.
You can also adjust the amount of coverage, if say you want it a bit patcher and further modify that by plugging in in a fractal breakup shader.

As well as that you have an editing tab. When you calculate the population you can have them visible on your quick render screen.



Here's the manner in which they will be displayed in the preview mode is textured, but I normally work with it set to boxes as its a clearer interface-



But I do sometimes switch to wireframe to check where branches near the camera are exactly-



With the editing tool you can select any individual object and do what you like with it, re-position it, change its size, rotate it on any axis or delete it altogether - useful to get trees out the way that render blocking the camera. For example in this picture I cleared a space of trees near the shore line to both give a clear sight of view and to expose the shore line to the camera and just to break up the trees a little.
So for example you could generate a random group of trees but then just with the delete tool make paths through it, glades and clearings, and if you wanted with the edit tool position every tree exactly here you want it to be.

But the place you really have the maximum control over everything is working in the node network, but that can be a bit daunting looking when you first start using terragen, here's the node network for this picture-



And that's just the top level of it. But once you start to get your head round how it works and it becomes more intuitive you begin to appreciate just how much it can let you do.

Hope that helps explain things. I know a lot of people dont really consider this sort of thing as art in any way as 'the computer does all the work' but I always find that a bit odd, like saying when I paint traditionally on canvas its just the 'brush doing all the work'. Its not the tools that count, its what you do with them I say.   }}}}

nice job

{{Thanks guys!

Halfy, thought this might highlight how the terrain generation can work  and just how much variety you can get from it.

Heres the alp pic above again, as this is the base for the rest. The settings for the terrain here are exactly as above.



Now regards setting up a picture and the issue of control- here's a second picture with the camera just moved within that terrain down to the shore line where I have created a scene.
In this example everything in the foreground is hand placed to create the picture-



But its still the same setting, all that's changed here is the camera and the objects.

Now the following examples, and this is the important bit, are all the same landscape with one exception (well two in one case!) -all I change between pictures is the 'noise' flavour for rendering the terrain.
By default the alpine fractal is set to 'perlin mix 1'- each of the following I have changed just that one setting.
Everything else is done by changing the surface shaders, the object models and the atmosphere.

desert version- all Ive done here is add a starta and outcrops shader to the terrain, surface shaders for the cliffs and fake stone shader for the ground.



Snowy- this was nice and easy, just a matter of adding surface layers for the snow and adjusting the lighting.



Islands- another straight-forward one- I just upped the water altitude to near the mountain tops and changed the plantlife and the lighting.



Alien -this  is the only one with more than one change to the terrain as I also altered the displacement on it for more interesting shapes and on the same displacement tab increased the spike limit to get ore pointy bits, and added a twist and shear shader to make the terrain lean. Throw in some odd coloured clouds, some greenish lighting and a bit of fog add some planets job done!



So you can get an idea of how versatile the terrain generation can be when used in combination with atmosphere, lighting and surface shaders. And all this is just tweaking (mainly) 1 tab in the terrain generation out of one terrain type. You also have the power fractals and the heightfields for that too which offers different things. And of course there are all the other settings I never touched in making these.
So it is best when you go in to have an idea of what it is you want to create- as the options otherwise are huge and you could just spend hours tweaking and experimenting if you dont have an idea what you want to begin with.
Hope that gives some insight into how it can work and how powerful the effects can be, even from a singular change.}}}

I should have realized I'd be opening the floodgates by asking a question.

I think I see the level of control. On another track, I see that things can look indistinguishable from reality from a certain distance, but takes real work up close. Which of course is what you normally get from a movie: foreground is set, background is rendered. You can sense the dividing line between the Hobbit and LotR movies, where PJ made more of an effort to construct sets for foreground in LotR, but pushed the render technology for the Hobbit. It produced a slighty uneasy feeling of things being not quite real, but was hard to put your finger on.

I should have realized I'd be opening the floodgates by asking a question.- Halfy

{{Its like when someone asks you a science question Halfy, the simpler the question the more complex the answer!

'I see that things can look indistinguishable from reality from a certain distance, but takes real work up close.'

Yeah there are several reasons for this chief among them the quality of the model and the resolution of the textures, plus if the model has specular and bump maps too. As I tend to work from freely available models put in the public domain the quality can be very variable model to model.
But terragen is primarily a landscape and atmosphere rendering program on a planetary scale.

Here for example is a short animation made by the makers of Terragen Planetside Software, and even at these high render levels and with a render farm to produce the end results there is still some unrealness to objects in the scene as opposed to ground or terrain or lighting effects. }}}

Fun video when you think it's all rendered. Some things to work on (some trees too solid, stream water too clear), but it's about 95% there, I'd say.

That really is amazing, considering it's being generated out of nothingness!  

Pettytyrant101 wrote: and even at these high render levels and with a render farm to produce the end results there is still some unrealness to objects in the scene as opposed to ground or terrain or lighting effects. }}}

The remaining unrealness is at about the same level as a mild drunk gives me. A couple stiff drinks and I might not be able to tell the two apart.

{{{{Petty, I couldn't get the files to upload to youtube. It seems to be a problem with the file extension. For some reason VLC converted .avi to .ogg when I trimmed them. I'll keep working on this....maybe I can solve the problem on this end....}}}}

that's your best yet gorgeous.

{{Thanks Figg- always helps I think to aim close to home, thats my stab at a Scottish loch }}}

{{Variations on a theme- seemed a waste to just use the setting for one picture }}

All quite nice and impressive. Now I'm trying to figure out why the last one seems the most obviously unreal to me. I think it's because the trees (and perhaps the birds) seem too dark. Perhaps the structure behind the viewpoint is non-existent so we don't get reflected light from behind us illuminating the immediate foreground?

The background is incredibly real. The reflection of the birds from the water is amazing.

'All quite nice'- Halfy

{{{ Americans! }}}

'Perhaps the structure behind the viewpoint is non-existent so we don't get reflected light from behind us illuminating the immediate foreground?'

{{Interesting you should note this. Although the terrain and indeed trees are behind the camera, they are a good bit behind the camera!
In that image I nicked a film and tv idea, the foreground is a set made up of a few bushes and a couple of trees shoved in front of the lens to create a fake foreground.
In reality all the bushes and trees are floating in the air a couple of metres above the water surface and a long way from the shore. }}}

Oh, so you have an entire landscape rendered, you just pick a point to view it from. In that case I'd think there'd be some backlight from the atmosphere at least, especially the clouds. Perhaps my intuition is wrong on this - it's very possible the program does a better job with light scattering than my head does.

so you have an entire landscape rendered, you just pick a point to view it from- Halfy

{{Sort of- this is where the question of how much control comes into it to a degree. If you use a power or an alpine fractal to generate the land then it covers the whole 'planet' and you then find a nice view you like- or more commonly you have an idea of what sort of picture you want to create and adjust the settings for the terrain to produce that sort of thing, then find a good viewpoint of it.

However you can also use heightfield terrains and these as default cover a square with side lengths of 1000m, though that's adjustable to as small or large as you want it.
Heightfield allows some more direct control over the shaping of the land and real world terrain can be loaded this way too.

As an experiment I rerendered the above one you thought looked the most fake without the added 'set' of foreground trees and bushes. }}}

So it seems like a full planetary atmosphere is always assumed, in which case I'd expect the foreground trees to have been lit a bit more.

If they get a touch more light, it would be .... if I can figure out your backwards Brit jargon... not quite nice.

it seems like a full planetary atmosphere is always assumed- Halfy

{{ Yes, no matter what type of generation you use for the terrain the atmosphere is always global - things affecting light in that picture are mainly the thickness of the atmosphere- the haze is high, there is also a cumulus cloud doubling as the mist the light it passing through on the way, and ceiling adjust for the blue sky is increased too- also increasing the 'thickness' of the atmosphere. The only thing reflecting light where the camera is would be the water, the shore is a long way behind it still so won't be reflecting anything back through the mist that far. So where the camera is placed there is effectively no ground for light to reflect off of.}}}

What I'm saying is all that atmosphere should light up the foreground trees more than they are.  The reason the background is so bright is because of light reflected off the atmosphere between us and it.  So those foreground trees should not be so dark in my estimation since we've got a whole hemisphere behind us shining light on them.

Mind you, the forward scattering we see in the direction of the view should be brighter than the backscattering I want to light up the foreground trees (if you can follow all of that), but I still feel they should be a touch brighter.  

It might be a camera/screen effect though: a photo or even a computer screen can't reproduce the outside intensity your eyes see, so everything is dialed down proportionally.  In which case, a dim but still quite visible foreground may end up looking nearly black.  If you could scale the brightness up of everything equally it may look correct.

its so dreamy and atmospheric, Elven- Figg

{{{ I was trying to create a golden light of the sort I imagine you get in Lorien in the right conditions}}

'I prefer the framing of the trees of the first version though.'

{{ Me too }}