The clumping variation doesn't do anything, even though it's active. Was just having a go with wild settings to see what sorta noise I could create and noticed in Clamped variation method, it doesn't do anything but the setting is exposed, where buoyancy is disabled. Might as well disable both it seems?
It does work, but it's very subtle compared to the other modes and not visible with default'ish settings.
To make it visible:
Set contrast to 5, offset to -1 and roughness to 1.
Set noise variation to anything but 0.
Clumping works now, but only within 0-1 range. Negative values seem to be ran through an abs transform as -0.5 gives the same result as 0.5.
Why it's way less strong and obvious than the other variation methods, I have no idea.
Oh yeah, it's very subtle isn't it. I couldn't even see a difference in displacement or colour added, needed to use a differnce shader.
PS a difference of perlin with unclamped variation produces a nice perlin billows mix without the meandering lines.
<terragen_clip>
<power_fractal_shader_v3
name = "Power fractal shader v3 01_1"
gui_use_node_pos = "1"
gui_node_pos = "900 420 0"
gui_group = ""
enable = "1"
input_node = ""
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
seed = "28089"
feature_scale = "1"
lead-in_scale = "1000"
smallest_scale = "0.01"
noise_octaves = "19"
obey_smoothing_filter = "1"
noise_stretch_XYZ = "1 1 1"
apply_high_colour = "1"
high_colour = "1 1 1"
apply_low_colour = "0"
low_colour = "0 0 0"
colour_contrast = "0.5"
colour_offset = "0"
colour_roughness = "1"
clamp_high_colour = "1"
clamp_low_colour = "1"
apply_displacement = "0"
displacement_direction = "1"
displacement_amplitude = "1"
displacement_offset = "0"
displacement_roughness = "1"
displacement_spike_limit = "1"
continue_spike_limit = "0"
adjust_coastline = "0"
coastline_altitude = "0"
coastline_smoothing = "30"
noise_flavour = "0"
ridge_smoothing = "0.1"
gully_smoothing = "0.1"
noise_variation = "1"
variation_method = "0"
buoyancy_from_variation = "0.25"
clumping_of_variation = "1"
better_colour_continuity = "0"
better_displacement_continuity = "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"
four-d_noise = "0"
four-d_noise_speed = "0.1"
reference_frame_number = "0"
blend_by_shader = "0"
blending_shader = ""
fit_blendshader_to_this = "0"
invert_blendshader = "0"
>
</power_fractal_shader_v3>
<power_fractal_shader_v3
name = "Power fractal shader v3 01"
gui_use_node_pos = "1"
gui_node_pos = "720 420 0"
gui_group = ""
enable = "1"
input_node = ""
gui_use_preview_patch_size = "1"
gui_preview_patch_size = "31.25 31.25"
seed = "28089"
feature_scale = "1"
lead-in_scale = "1000"
smallest_scale = "0.01"
noise_octaves = "19"
obey_smoothing_filter = "1"
noise_stretch_XYZ = "1 1 1"
apply_high_colour = "1"
high_colour = "1 1 1"
apply_low_colour = "0"
low_colour = "0 0 0"
colour_contrast = "0.5"
colour_offset = "0"
colour_roughness = "1"
clamp_high_colour = "1"
clamp_low_colour = "1"
apply_displacement = "0"
displacement_direction = "1"
displacement_amplitude = "1"
displacement_offset = "0"
displacement_roughness = "1"
displacement_spike_limit = "1"
continue_spike_limit = "0"
adjust_coastline = "0"
coastline_altitude = "0"
coastline_smoothing = "30"
noise_flavour = "0"
ridge_smoothing = "0.1"
gully_smoothing = "0.1"
noise_variation = "1"
variation_method = "0"
buoyancy_from_variation = "0.25"
clumping_of_variation = "0"
better_colour_continuity = "0"
better_displacement_continuity = "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"
four-d_noise = "0"
four-d_noise_speed = "0.1"
reference_frame_number = "0"
blend_by_shader = "0"
blending_shader = ""
fit_blendshader_to_this = "0"
invert_blendshader = "0"
>
</power_fractal_shader_v3>
<difference_scalar
name = "Difference scalar 01"
gui_use_node_pos = "1"
gui_node_pos = "800 340 0"
gui_group = ""
enable = "1"
input_node = "Power fractal shader v3 01"
gui_use_preview_patch_size = "1"
gui_preview_patch_size = "31.25 31.25"
input_2 = "Power fractal shader v3 01_1"
>
</difference_scalar>
</terragen_clip>