First test : Prairie

[Antoine]

Here is my first test realisation, very simple one, with Terragen.
I need to improve so I am waiting for expert advices.

[Alcaeru]

In my opinion, that's a very good first render. The only thing I have to say is that there is a grey looking mountain in the background that looks a little unsurfaced and perhaps isn't meant to be there. Maybe you could move the camera slightly so that it is not in the shot.
Good job though, I love the grass and flowers.

[Antoine]

Thanks Alcaeru.
I'll try to fix that later on.

[Tangled-Universe]

Welcome Antoine

First render? Very good!

I agree with Alcaeru about the mountain lacking a bit of surfacing.
You can either try to remove it from the view or perhaps try to make use of it by bringing it more in view and texture it nicely

I noticed something else, actually, that in the foreground in between the grasses you can see flat shading.
You can try to add a powerfractal with small scales and low displacement value to create some bump.
Then add some surfacelayers (2 or 3) and it will likely look more natural.
You can make nice gritty soil by using 2 or 3 fake stone shaders with small scales.

Let me know if you need any help. Getting the bump and stones is relatively easy, but the colours can be a bit tricky to make realistic.
I do find that one of the most difficult things in TG2, actually.

Cheers,
Martin

[TheBadger]

Hi,
Great render. Don't like the dogwood or roses though, they just don't fit for me. They look nice, but I think they would not be found in a natural prairie. At least not in my part of the world

[Antoine]

Thank you all for you comments,

Martin, I definitely agree with you, but before I will have to do some tests and works on these 2 area : bump and stones.
In fact, a few days ago, I have bought (from NWDA) the two stones packs to begin with and when I see what is all about, it looks like very difficult to handle (if I had to do that by myself).
I have to understand the way the nodes are working.

For example, when it is said "connect to surface shader chain", in the surface layer node, do I have to create a new shader ? Because the only shader available (after having generated a terrain) is the base color shader and when I connect the surface layer to the blend connector (there are no other one) of that shader, nothing appears.
I know for you all this may be a stupid question but I have to understand.

[Tangled-Universe]

In this case you're confusing "blending" with "mixing in/adding to".

The "blend shader" function in TG2 means "mask channel" and mostly expects a greyscale input to allow the presence of that particular layer to be broken up by the input of that "blend shader" port.

What you need to do to hook the stones shader up in the network  is to connect the "base colours" output to the the most left connection of the surface layer you mentioned. Then connect the output of that surface layer into the planet node, since that's where the "base colours" originally was connected to.

You now basically added a layer in between "base colours" and "planet 01" node.
That's what generally is meant by "connect to (surface) shader chain"

If you need more help with the stones then please let know.

Cheers,
Martin

[Antoine]

Many thanks Martin for your explanations, that works now.
I am now going to play with these packs for color and bump variations in order to get some training of these.

An another question : what is the "fractal breakup" all about ?
And if I wanted to place rocks to a precise area of the generated terrain what should I do ?

[Tangled-Universe]

Many thanks Martin for your explanations, that works now.
I am now going to play with these packs for color and bump variations in order to get some training of these.

An another question : what is the "fractal breakup" all about ?
And if I wanted to place rocks to a precise area of the generated terrain what should I do ?

Fractal breakup is another type of blending where you can also use a greyscale value to breakup/mask the surface layer.

However, it offers more options, as you can set the amount of breakup in the surfacelayer.
If the surface layer coverage = 0.5 and the fractal breakup = 1 then the surface layer's coverage will ben entirely controlled by the greyscale values of the breakup shader. (since the fractal is connected to the breakup input we call it breakup shader, but if it would be connected to the blendshader input we call it blendshader)
If you set fractal breakup to 1 and surface layer coverage >0.5 then the effect of the breakup will be reduced.

You may consider the next as possibly not true, but I believe when you have the surfacelayer being controlled by a breakup shader that you can achieve extra interesting breakup effects by using "distort by normal" for example. You can find that parameter in the last tab of your breakup fractal.
It might also be that you can only use this "distort by normal" effect when you use the breakup fractal as a surface shader itself.

As you can see a fractal can serve many purposes. You can use to blend/mask surfaces or as breakup or even as a surface shader itself.
A lot to explore!


You can use a painted shader, for example, to restrict stones to precise areas.
Also, if you want to restrict it to the foreground only, you can also use a distance shader to mask stones (create shader -> colour shader -> distance shader)
If you do an advanced search here for "painted shader" or "distance shader" + my username then you'll probably find a post or two where I describe the process.
Same you can try for other usernames like Dandel0 (likely I made a typo here) or Dune.
They post a ton of information as well.

Good luck and have fun

Cheers,
Martin

[Antoine]

Thanks Martin for your help and these detailled explanations.

[Antoine]

Here is an update of the scene. I have added some cirrus clouds, changed the terrain color with some fractal noise, and some rocks (my first ones).
The setting is a little higher : detail at 0.9, AA 10, GI 3/3 raytrace objet and atmosphere. It took 7h45 with an i7 950.
There is a little oddity : at the upper right one can see 2 patchs of grass on one rock. Well it is not so bad after all, because in nature it may well happen
that grass grows on some muddy part of a rock. But this could be bothering in other situations.
What can I do to avoid this ?

[Tangled-Universe]

To avoid this you must make sure that the mud shader is somehow being masked already, that makes things a lot easier since you can use that same mask to tell other shaders to use it as well or use the inverted version of it. The latter is what you would need to do.

Suppose you already have a density shader for your population, most of the times that would be a distribution shader 04. Connect the output of your mud mask to the blendshader input of your density shader (the distribution shader that is in this example) and enable "blend by shader" + "invert blendshader".

(In addition to this you can try something more advance and that is to connect a colour adjust shader in between the mask and the density shader. The colour adjust works like Photoshop Levels function and allows you to alter the contrast and coverage of your mask without altering the original mask (since you need that for the mud).)