Terragen 2 TerraTurf Tutorial
(TTTTT)
By dandelO.
Help Files
Grass
Help Files
Grass
20th October 2007.
For ages I've required a way to cover VAST areas of real looking grass to take
my Terragen 2 work to the next level.
So, here's the easiest way I've found of creating a
convincing looking grass surface with shaders directly inside T2, without any objects!
Oh, did I mention that this method renders as fast as a single colour surface
layer does? And that the coverage is on a planetary scale?
It does and, it is! ;)
Right, let's get straight to the Terra-Turfing...
my Terragen 2 work to the next level.
So, here's the easiest way I've found of creating a
convincing looking grass surface with shaders directly inside T2, without any objects!
Oh, did I mention that this method renders as fast as a single colour surface
layer does? And that the coverage is on a planetary scale?
It does and, it is! ;)
Right, let's get straight to the Terra-Turfing...
Here's the .tgd for the tutorial scene shown above.
.tgd 34.3kb: DOWNLOAD
Groundrock wiring explained.
Instead of just adding layers through the main window you should definately get yourself used to working in the bottom right hand side of T2, that's where the real magic happens and the possibilities of t he node network system are limitless.
I add all my shaders this way because of the control you have over everything as opposed to the 'add layer -add child- move up/down' method, don't do that, it's more hassle than it's worth if you have real specifics in mind.
Here we're using blank surface layers as distribution shaders for all elements of the terrain texturing, read on...
Part 1 - Rock
1. Open Terragen 2, add a default powerfractal(PF) terrain and get a nice rock surface texture going for the ground. For this tutorial scene it's already done, your rock surface shaders are in the group 'Rock Base Shaders'. They consist of 3 PF colour shaders.
2. Make new 2 new 'surface layers' in your 'shaders group', call one 'rock mud mixer' the other 'final rock surface'. Delete the fractal breakup shaders, they're not required. Set both shaders to full coverage, no colour.
3. Plug your last rock shader(rock base 3) into the input of 'rock mud mixer', next plug 'rock mud mixer' into the 'colour function' of 'final rock surface'.
Now we take the 'base colours' input OUT of 'planet 1' and plug it into the
input' of 'final rock surface', which will then be plugged into 'planet 1' instead of 'base colours'.
input' of 'final rock surface', which will then be plugged into 'planet 1' instead of 'base colours'.
4. Open the settings for 'rock mud mixer' and ensure that 'Apply colour' has been unchecked on this surface layer, I'm only using it for it's distribution functions and I find a lot more can be done with a surface layer than with an actual distribution shader. I call this 'Rock mud mixer' because it will only serve to distribute the mud beneath the grass.
That's the rock taken care of, now for the grass which is why we're here in the
first place, isn't it?
Part 2 - Grass and Mud
5. Make a new group and call it 'Grass shaders'.
In this group add, 2 new PF shaders and 3 new surface layers(delete 2 of the breakup shaders, keep the other aside, we'll use it soon)
In this group add, 2 new PF shaders and 3 new surface layers(delete 2 of the breakup shaders, keep the other aside, we'll use it soon)
6. Take one surface layer, call it 'grass surface layer', uncheck 'apply colour' and place it at the bottom of the group. See 'Node Network view' for the following wiring...
*** Call another surface layer 'grass distribution' and plug it into the 'child layers'
input of 'grass surface layer'
Plug one PF shader into the 'child layers' input of 'grass distribution' Call this
PF 'fractal grass shader' it's your grass.
With the remaining surface layer and PF shader, wire them together with the
PF as the child to the surface layer and call them 'Fractal mud shader' and
'mud distribution'.
'Mud distribution' goes into the 'rock mud mixer' child layer input and 'grass
surface layer' goes into 'final rock surface' child layers input.***
input of 'grass surface layer'
Plug one PF shader into the 'child layers' input of 'grass distribution' Call this
PF 'fractal grass shader' it's your grass.
With the remaining surface layer and PF shader, wire them together with the
PF as the child to the surface layer and call them 'Fractal mud shader' and
'mud distribution'.
'Mud distribution' goes into the 'rock mud mixer' child layer input and 'grass
surface layer' goes into 'final rock surface' child layers input.***
NODE NETWORK VIEW
(click for fullsize)
Now we get to the distribution and breakup area. I'll list all the numerical
values I've used for each shader here, also the RGB values for the grass/mud
shaders.
values I've used for each shader here, also the RGB values for the grass/mud
shaders.
7. Open 'Grass surface layer', set the coverage to 0.9 and then visit the slope constraints tab.
Set 'Maximum slope angle' to 40, 'fuzzy zone' 10. Click 'use Y for slope'.
Use the fractal breakup shader you didn't delete earlier to break up this layer.
Open the 'breakup shader' settings and set: 'Feature scale' 1, 'Lead in scale' 100 and 'Smallest scale' 0.1
Open the 'breakup shader' settings and set: 'Feature scale' 1, 'Lead in scale' 100 and 'Smallest scale' 0.1
No colour or displacement, choose a 'noise flavour' you like.
8. Open 'Grass distribution' Set, Coverage 0.8 and use the same breakup shader as before here aswell. Next,visit slope constraints and set this one to Max 40, Fuzzy 15. Use Y for slope.
9. Open 'Fractal Grass Shader' now we can set up these blades!
10. Open 'Mud distribution'. We want this mud to be visible just beneath and around the grassline so, uncheck 'Apply colour', coverage 1, and then, slope constraints we'll set to Max 45, Fuzzy 15. Use Y for slope.
11. Go to 'fractal mud shader' Feature scale 0.01 lead in scale 0.02 smallest scale 0.005
RGB High colour 41, 28, 22, Low colour 34, 27, 16
Choose a noise flavour.
No displacement. in this tutorial.
12. Find your POV and render!
The key to these scales is 'tiny and tight'.
Very small scales with a very tight range.
Ok, Feature scale 0.007, Lead in scale 0.009, smallest scale 0.003
This scale range means that each peak of displacement will have a general size of 7mm, a largest size of 9mm and smallest size of 3 mm.
The noise octaves are very low now you'll see(3 hopefully if it's correct), the higher these octaves go when you're setting lead in/smallest scale the longer it will take to render as it's a more complexed scale range to deal with and calculate, this grass however, has a tiny, tight range which makes it VERY fast to render.
The noise octaves are very low now you'll see(3 hopefully if it's correct), the higher these octaves go when you're setting lead in/smallest scale the longer it will take to render as it's a more complexed scale range to deal with and calculate, this grass however, has a tiny, tight range which makes it VERY fast to render.
Visit the displacement tab and set it to 'Along vertical', amplitude to 3, offset 0, roughness 1, spike limit 1 and check 'continue spike limit'.
Go to the colour tab. Change 'High colour' to RGB values 94, 103, 55 and 'Low colour' to 31, 34, 16.
Set contrast to 0.5, offset 0, roughness 5.
Set noise flavour to 'perlin ridges'. Grass!
Go to the colour tab. Change 'High colour' to RGB values 94, 103, 55 and 'Low colour' to 31, 34, 16.
Set contrast to 0.5, offset 0, roughness 5.
Set noise flavour to 'perlin ridges'. Grass!
Now, the grass distribution layer and grass surface layer are laying this all over
the planet keeping it from the high slopes where grass doesn't belong but, it's
growing out of the rock... Let's make some mud, we won't spend much time
doing this, as long as it's brown ;)
the planet keeping it from the high slopes where grass doesn't belong but, it's
growing out of the rock... Let's make some mud, we won't spend much time
doing this, as long as it's brown ;)
This is just a slightly wider slope range than the grass distribution
so the grass will always appear on mud, not rock.
11. Go to 'fractal mud shader' Feature scale 0.01 lead in scale 0.02 smallest scale 0.005
RGB High colour 41, 28, 22, Low colour 34, 27, 16
Choose a noise flavour.
No displacement. in this tutorial.
12. Find your POV and render!
I hope this helps someone, I know I've been needing this for a long time for loads of stuff.
It won't be pretty if viewed closeup(a matter of mm) as it's really only just tiny (but ugly) perlin spikes.
At a 1 to 2 metre height above the ground it still holds up though, this tutorial scenes height above the surface is about 7m. for the main render camera. The directors camera is set at about 1.65m. to view this pov, select the 'directors renderer' and then click on 'view camera' twice.
Good luck and, keep me posted on any ideas you have for improvement or renders you create with it.
Thanks,
dandelO.
dandelO.
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