Rolling Hills. Again?

Started by TheBadger, August 09, 2012, 08:21:12 AM

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TheBadger

My every effort has failed.

I cannot believe that this is as hard as I'm finding it.
All I want is what you see in this image at real world scale.
[attachimg=1]

Anyone?
It has been eaten.

dandelO

A basic Perlin fractal should give you this type of terrain. Just don't have a tiny smallest scale. Make your 'smallest scale' the same as your 'feature scale', and maybe lower the default displacement multiplier.
Try this(copy the entire code and paste with ctrl+v into your node network)...

<terragen_clip>
<power_fractal_shader_v3
name = "Fractal terrain 01"
gui_use_node_pos = "1"
gui_node_pos = "-680 640 0"
gui_group = ""
enable = "1"
input_node = ""
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
seed = "45710"
feature_scale = "500"
lead-in_scale = "2500"
smallest_scale = "500"
noise_octaves = "4"
apply_high_colour = "0"
high_colour = "1 1 1"
apply_low_colour = "0"
low_colour = "0 0 0"
colour_contrast = "0.5"
colour_offset = "0"
colour_roughness = "5"
clamp_high_colour = "1"
clamp_low_colour = "1"
apply_displacement = "1"
displacement_direction = "1"
displacement_amplitude = "250"
displacement_offset = "0"
displacement_roughness = "0.875"
displacement_spike_limit = "0.25"
continue_spike_limit = "1"
adjust_coastline = "0"
coastline_altitude = "0"
coastline_smoothing = "30"
noise_flavour = "0"
noise_variation = "2"
variation_method = "2"
buoyancy_from_variation = "0.5"
clumping_of_variation = "0.25"
noise_stretch_XYZ = "1 1 1"
distort_by_normal = "0"
distortion_by_normal = "5"
lead-in_warp_effect = "1"
lead-in_warp_amount = "0.75"
less_warp_at_feature_scale = "1"
allow_vertical_warp = "0"
blend_by_shader = "0"
blending_shader = ""
fit_blendshader_to_this = "0"
invert_blendshader = "0"
>
</power_fractal_shader_v3>
</terragen_clip>


A regular Perlin terrain should be nice and smooth-rolling, keep the octaves low, I'd use the same smallest scale as I would feature scale. Lead-in scale could also be the same but you might want it to be larger to spread out the features somewhat. I wouldn't use any other 'noise flavour' than Perlin, it should be smoothest.

Try a few 'random seed' clicks on this clip, should be good for such a terrain. You can also mess around with the warp and variation settings, above they're all the defaults from adding a new power fractal terrain in the 'terrain' tab's 'add terrain' button.

TheBadger

Thanks DandelO,
That gives me pretty much exactly the kind of hill I wanted. The trouble is still that there seems to be no way to get the hills sized right.
I need them to look like your (same spacial distance from one another) but no bigger than the reference image. Perhaps even smaller.

Of the things that you mentioned, the only thing I could not find is the "displacement multiplier". I could not even find a result by putting the term onto the search field of the wikki. I have heard it before but could not find a direct reference to where and what it is. Is the displacement multiplier how I get my scale real world?

All I can think of now is to make all of my objects gigantic in order to make the hills look smaller. But I really don't want to do that.

Thanks for the info Martin. You got me as close as I have been.
It has been eaten.

Kadri

Try this too please.
I made this more like small hills.
It is mostly like Martins's file but different parameters.
Probably the most different part is the noise variation. I made it zero.
The hills are a little more uniform.

Play with the other parts and i hope you will get what you want Michael.

[attachimg=1]



dandelO

* Think I meant displacement amplitude, whatever the term, I just meant to lower the displacement in the fractal's displacement tab from the defaults of '2000m' for a regular fractal terrain.

I'd maybe just remove a zero from every scale field(50, 250, 50), and also again from the displacement tab, too(25).
That'll give you the same overall noise but shrink it by a factor of 10. Maybe even try the same scale in each field, the clip above was just an example of a roughly rounded noise. :)

TheBadger

Quotethe clip above was just an example of a roughly rounded noise.
Perfectly (for me) rounded!

Kadri,
I was able to see the differences in your file from Martins, so I was able to find which parameters are important to this. Thank you, the file helped.

So thank you DandelO and Kadri, between the two .tgds I was able to get this finely!

As it happens, "Buoyancy from variation" is an important parameter. But I have never played with it because the details about it in the wiki don't really tell me anything. It appears that its only having an effect now because of some other parameter that was changed in the files. But "Buoyancy from variation" seems to be giving me the most control over the scale. Or at least thats what I think I am seeing?
It has been eaten.

TheBadger

"Buoyancy from variation" Ok, scratch that part. But I am still getting what I wanted. SO the thanks is still good ;)

"Buoyancy from variation" is a strange parameter though. I thought it was raising my low areas up by entering increasingly larger negative numbers. But is seems to raise the entire terrain, I guess giving the planet a larger volume over all.
It has been eaten.

Dune

It's nice to play with these variables. Buoyancy makes the noise more contrasting, and you can get some nice terrains by carefully playing with it.

Hetzen

Quote from: TheBadger on September 14, 2012, 07:36:20 PM
My every effort has failed.

I cannot believe that this is as hard as I'm finding it.
All I want is what you see in this image at real world scale.
[attachimg=1]

Anyone?

You need to start off by working out how big those features are and setting your scales and displacements accordingly, then set your camera height to human eye level to see how your changes look in 'world space'.

Have a look at this clip, there are some notes attached talking through the process. I've put in some variation, but you might want to pull that back. Using Shader previews let you know what each stage of the process is doing to the greyscale.

Quote<terragen_clip>
   <power_fractal_shader_v3
      name = "Power fractal shader v3 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-920 720 0"
      gui_group = "Terrain"
      enable = "1"
      input_node = ""
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      seed = "63247"
      feature_scale = "9"
      lead-in_scale = "9"
      smallest_scale = "9"
      noise_octaves = "2"
      apply_high_colour = "1"
      high_colour = "1 1 1"
      apply_low_colour = "1"
      low_colour = "0 0 0"
      colour_contrast = "0.8"
      colour_offset = "0"
      colour_roughness = "0"
      clamp_high_colour = "1"
      clamp_low_colour = "1"
      apply_displacement = "0"
      displacement_direction = "1"
      displacement_amplitude = "30"
      displacement_offset = "0"
      displacement_roughness = "0.1375"
      displacement_spike_limit = "0.19375"
      continue_spike_limit = "0"
      adjust_coastline = "0"
      coastline_altitude = "0"
      coastline_smoothing = "30"
      noise_flavour = "0"
      noise_variation = "1.4"
      variation_method = "2"
      buoyancy_from_variation = "0.6125"
      clumping_of_variation = "0"
      noise_stretch_XYZ = "1 1 1"
      distort_by_normal = "0"
      distortion_by_normal = "5"
      lead-in_warp_effect = "0"
      lead-in_warp_amount = "0.5"
      less_warp_at_feature_scale = "0"
      allow_vertical_warp = "0"
      blend_by_shader = "0"
      blending_shader = ""
      fit_blendshader_to_this = "0"
      invert_blendshader = "0"
      >
   </power_fractal_shader_v3>
   <note
      name = "Note 02"
      gui_use_node_pos = "1"
      gui_node_pos = "-600 640 0"
      gui_group = ""
      gui_node_size = "665.6878744 84.20709383 1"
      gui_note_text = "This is an example of the sort of effect we can apply to a greyscale, but not so easily apply to a displacement.&#xD;&#xA;&#xD;&#xA;Look up Gain Scaler in the wiki, and have a look at the graph shape. What is happening here, is that we are applying that curve to the greyscale, to bring it towards the curve shape. In this instance, flatter valleys and rounder tops."
      gui_note_text_colour = "0 0 0"
      gui_note_use_custom_text_size = "0"
      gui_note_custom_text_size = "10"
      gui_node_colour = "0.9900000095 0.9599999785 0.6100000143"
      >
   </note>
   <note
      name = "Note 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-640 800 0"
      gui_group = ""
      gui_node_size = "741.8799009 78.84403691 1"
      gui_note_text = "Displacement is turned off. I'd rather use values of colour between 0 to 1 to drive a displacement shader, because we can apply all kinds of effects to this greyscale."
      gui_note_text_colour = "0 0 0"
      gui_note_use_custom_text_size = "0"
      gui_note_custom_text_size = "10"
      gui_node_colour = "0.9900000095 0.9599999785 0.6100000143"
      >
   </note>
   <displacement_shader
      name = "Displacement shader 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-860 360 0"
      gui_group = ""
      enable = "1"
      input_node = ""
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      function = "Gain scalar 01"
      displacement_direction = "1"
      displacement_multiplier = "3"
      >
   </displacement_shader>
   <note
      name = "Note 03"
      gui_use_node_pos = "1"
      gui_node_pos = "-600 440 0"
      gui_group = ""
      gui_node_size = "658.0590595 88.7843828 1"
      gui_note_text = "The moddified greyscale is now used to displace the planet surface. The displacement amount in this case is set within the node, but you could quite easily leave it as 1, instead multiplying the output of the previous node by the amount of your wanted displacement."
      gui_note_text_colour = "0 0 0"
      gui_note_use_custom_text_size = "0"
      gui_note_custom_text_size = "10"
      gui_node_colour = "0.9900000095 0.9599999785 0.6100000143"
      >
   </note>
   <gain_scalar
      name = "Gain scalar 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-860 520 0"
      gui_group = ""
      enable = "1"
      input_node = "Power fractal shader v3 01"
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      gain = "Constant scalar 01"
      >
   </gain_scalar>
   <compute_terrain
      name = "Compute Terrain"
      gui_use_node_pos = "1"
      gui_node_pos = "-940 300 0"
      gui_group = "Terrain"
      enable = "1"
      input_node = "Displacement shader 01"
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      gradient_patch_size = "20"
      smooth_surface = "0"
      >
   </compute_terrain>
   <constant_scalar
      name = "Constant scalar 01"
      gui_use_node_pos = "1"
      gui_node_pos = "-860 560 0"
      gui_group = ""
      enable = "1"
      input_node = ""
      gui_use_preview_patch_size = "0"
      gui_preview_patch_size = "1000 1000"
      scalar = "0.94375"
      >
   </constant_scalar>
</terragen_clip>

TheBadger

Thanks  a lot guys. Everything is understood now. I got just what I wanted! Can't believe this was so hard for me :o
Funny a mountian should be easier than a Molehill  :P

Camera is 6'1" off the ground, so scale here is working fine.
[attach=1]



Thanks Dune^^ that may be the first post I have seen on the subject.
It has been eaten.

Tangled-Universe

Quote from: Dune on September 15, 2012, 04:09:25 AM
It's nice to play with these variables. Buoyancy makes the noise more contrasting, and you can get some nice terrains by carefully playing with it.

I don't know Ulco.

Your first example has noise variation @ 200 with 100 for buoyancy.
Second example has noise variation @ 2 and 80 for buoyancy.
Third example has both set to 0.

From that you can't draw that conclusion. It's a change between 2 parameters and not 1.
In my experience noise variation is a very strong modulator of the noise function.
Noise variation at these high levels acts more likely as "clumping of variation". Resulting in flat areas and sudden increase of localized noise.
You explain and account that sudden increase as contrast because of buoyancy.
You may be right, but I'm just not sure about the reasoning and it's also not really what I see in my experiment. Although those were mostly on clouds, honestly.

Dune

You're right, Martin, that it's not as simple as I stated it (nothing is in TG  ;)), but low variation and low buoyancy gives an overall smoother gray noise, whereas if you increase them the contrast increases, whether clumpy (with variation up) or more spread out (with low variation, but buoyancy up). I just wanted to point out to our fellow terrageneers that it's nice to see what happens if you play with these numbers, just to understand the workings.

Tangled-Universe

Oh yes absolutely. Playing with it in the way you demonstrated is definitely a good way of learning understanding. In this case the discussed TVR would sort this out for us.