Hi
Is it possible to divide cloud scape in different depth layers?
(I know that is possible create different layers of clouds, turn the visibility ON\ OFF and render separate images)
What I'm looking for is something different.
I want the ability to slice the cloudscape in Depth layers (for example: background / mid/ foreground) render 3 different images with alpha re project the images on planes in NUke or maya and render the final animation in there.
Cheers
D
This capability will be included in v2.5 (later this year), as part of the Render Layers feature.
You can do this in the current version using a somewhat manual process. You can use a Distance Shader to control where the clouds are rendered, by using the Distance Shader as the "blend shader" for whatever shaders are driving your clouds. The Distance Shader creates a ramp from one value to another (usually from 0 to 1, or black to white), so you'll need to combine two Distance Shaders to produce a region of white surrounded by a region of black.
Copy and paste this example into the Node Network:
<terragen_clip>
<distance_shader
name = "Distance shader 01"
gui_use_node_pos = "1"
gui_node_pos = "300 420 0"
gui_group = ""
enable = "1"
input_node = ""
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
apply_far_colour = "1"
far_colour = "1 1 1"
apply_near_colour = "1"
near_colour = "0 0 0"
far_distance = "8001"
near_distance = "8000"
distance_mode = "1"
camera = ""
clamp_far_colour = "1"
clamp_near_colour = "1"
>
</distance_shader>
<distance_shader
name = "Distance shader 02"
gui_use_node_pos = "1"
gui_node_pos = "300 360 0"
gui_group = ""
enable = "1"
input_node = "Distance shader 01"
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
apply_far_colour = "1"
far_colour = "0 0 0"
apply_near_colour = "0"
near_colour = "1 1 1"
far_distance = "16001"
near_distance = "16000"
distance_mode = "1"
camera = ""
clamp_far_colour = "1"
clamp_near_colour = "1"
>
</distance_shader>
<cloud_fractal_shader_v3
name = "Density fractal 01"
gui_use_node_pos = "1"
gui_node_pos = "200 280 0"
gui_group = "Atmosphere"
enable = "1"
input_node = ""
gui_use_preview_patch_size = "0"
gui_preview_patch_size = "1000 1000"
seed = "54041"
feature_scale = "500"
lead-in_scale = "20000"
smallest_scale = "10"
noise_octaves = "13"
apply_high_colour = "1"
high_colour = "1 1 1"
apply_low_colour = "0"
low_colour = "0 0 0"
contrast = "1"
coverage_adjust = "0"
roughness = "1.5"
clamp_high = "0"
clamp_low = "0"
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"
noise_variation = "1"
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 = "0.5"
less_warp_at_feature_scale = "1"
allow_vertical_warp = "1"
blend_by_shader = "1"
blending_shader = "Distance shader 02"
fit_blendshader_to_this = "0"
invert_blendshader = "0"
>
</cloud_fractal_shader_v3>
</terragen_clip>
The first shader produces a ramp from 8000 metres to 8001 metres that goes from black to white. The second shader then ramps back down to black from 16000 metres to 16001 metres. "Apply near colour" is disabled on the second shader so that it only ramps towards black but doesn't change anything else that was produced by the first shader. It fades from whatever ramp was produced by the first shader at 16000 towards black at 16001.
The purpose of this is to produce cloud between 8000 and 16000 metres away from the camera.
I also changed the distance mode from "distance (spherical)" to "z depth (planar)" so that you can map them onto planes.
When you plug these Distance Shaders into your own fractals, make sure to enable "blend by shader" on the fractals.
There are some limitations to the Distance Shader method. It turns off visible and cloud-casting clouds, so you'll only get shadows cast by clouds that are in the depth range you're rendering. Renders can take longer than they would if the renderer was able to do the clipping for you. Terragen 2.5 will be able to do this in a more efficient way with the Render Layer settings.
Matt