tu-canyon wall tutorial

8/3/2019 TU-Canyon Wall Tutorial

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Canyon Wall Tutorial

by

Martin Huisman



Introduction:

I’ve been working on this image for well over 4 weeks. Think it took me approximately.

120h to set up the scene (including countless test-renders) and another 60 hours to renderit in total.

This image was created using many clipfiles, knowledge gained from the forum and of course (and the most) lots and lots of fiddling with the settings, making test-render aftertest-render.

In this tutorial I will try to cover each step I made in creating this scene. From setting up

the general terrain form, adding displacements, details, lighting and rendering.

I hope it will be of good use to you and I look forward and hope to see some of theaspects to be implemented in your projects☺

This tutorial will cover the majority of aspects involved creating my Canyon Wall image.Please bear in mind that all the settings and node workflow is not the only way to achieve

similar results/effects.

Also please bear in mind that I’m like many others still learning this piece of magnificent

software and therefore some explanations or chosen methods/techniques aren’t correct.

In case of errors or unclarity please mail me or add me to your IM:

[email protected]

Enjoy!

mailto:[email protected]





Chapter 1: the node-screenshot of this project

As some of you may have already seen on my previous posted screenshots at the forum I

use a lot of clipfiles and I group them to keep track on my nodes.This is essential to keep track on your work and will make it also a lot more easier to

quickly adjust certain features of your image.Let’s take a look at the complete node-setup in figure 1 below to see what I mean.

Fig 1: complete node-setup of this project

Higher res: http://forums.planetside.co.uk/index.php?topic=3217.msg36421#msg36421

http://forums.planetside.co.uk/index.php?topic=3217.msg36421%23msg36421

http://forums.planetside.co.uk/index.php?topic=3217.msg36421%23msg36421



Chapter 1: setting up the canyon shape and camera

Some time ago I ran into a topic which contained a clipfile with a basic wall shape based

on function nodes. Unfortunately I can’t remember the topic starter nor the originalcreator of this node-setup. So kudos to the yet anonymous creator.

Fig 2: node-group specific for the general terrain form

This is the hardest part for me to explain, because I honestly don’t really understand how

these function-nodes result in this particular shape.Like I said I’m not the original creator of this function-node setup but it’s pretty obvious

it has been created using David Burnett’s ‘A Function Only Landscape’ which you can

find here: http://forums.planetside.co.uk/index.php?topic=1166 Please visit his tutorial for the best explanation on how to create the overall canyon

shape. So in this case it’s hardly an explanation, more of a ‘how to’.

The constant scaler ‘h=width of canyon’ not really surprisingly determines the width of the canyon. In this case its value is 15. Of course you can increase or decrease this value,

whatever is convenient to you. Don’t forget to adjust the height of the canyon which is

determined by the constant scalar ‘h_1 = height of canyon’. Value for this scalar is 500.

http://forums.planetside.co.uk/index.php?topic=1166




Chapter 2: creating outcrops and base details

Though linked and activated, the heightfield-shader is not in use in this setup, so I could

have deleted it in the schematics, but for unknown reasons I didn’t ☺ After the compute terrain there is 1 PowerFractal (PF), base colours and 2 other PF’s.

The PF’s apply displacement at various scales on the terrain and are blended by anotherPF (Powerfractal shader v3 01_1) responsible for adding variation in the displacements.The 3 PF’s have different scales, respectively 40, 1 and 0.1 metres, creating larger

outcrops and additional detail.

Result:

Fig 4: a closer look at the PF generated displacements as seen in figure 3.



Chapter 2: creating a cracked and rocky surface

This is one of the fun parts to create for me and thanks to Moodflow I was able to design

a node-setup way less complicated and much faster to render than my previously showncracks. So, thanks John! You can view the screenshot I used from his work here:

http://forums.planetside.co.uk/index.php?topic=2944.0

Fig 5: node-setup for creating the cracks, derived from Moodflow’s screenshot.

The cracks are built up by 4 separate cracksizes and displacements, all stacked by using

surface layers parenting/sibling.When using ‘exotic’ type of displacements like these I always create a ‘base’ surface

layer which allows me to control the amount of displacement (using the coverage setting)

and to constrain it to certain heights and slopes. In this case this ‘base’ layer is ‘ surface

layer 02’.

This base layer has a function group attached to it and like I said I’m not really good at

functions, but I’ll try☺





The ‘Voronoi Scale’ is a constant scalar and determines the size of the cracks in metres.This is being fed into a ‘Voronoi 3D diff scalar’ which creates the voronoi shapes. Also

connected to the 3D scalar is the ‘Get Position’ for input of starting point of the function.

The 3D scalar is then connected to a ‘Power Colour’ together with a constant colour.According to John (Moodflow) this constant colour ‘rounds off’ the edges of the voronoi

to make them look less artificial.All together this is being fed into the displacement input of the corresponding surfacelayer.

From top to bottom there are 4 function groups creating the cracks in a size increasing

order. The sizes (values for constant scalars) used in this image were 12, 24, 48 and 96.From top to bottom the displacement of the cracks is also in an increasing order,

displacement multipliers set to 2.4, 2.6, 2.8 and 3. All with an offset of about 0.7.

Result:

Fig 6: example showing the cracks. The red box is a crop render at higher detail for visualization

purposes. Since the cracks are fine rendering at high quality is adviced (>0.65)



Chapter 3: creating the strata

So, now the probably most important part of this image/tutorial, the strata.

The strata were created by mixing strata with different settings as shown in figure 7.

F

What I’ve basically been trying to do is to mix strata with different appearances in

hardness, plateau buildup and hard layer

and also some ‘classical’ strata shapes.There are 2 great references/tutorials of the strata and outcrops shader on the web

from Oshyan and one from Piliph whichtr

Strata and outcrops shader node reference by Osh

ig 7: node connections and shader settings for the strata and outcrops

spacing to give the rocks a flaky stacked look

, one

is in French, but with the use of googleanslation it’s quite easy to understand.

yan: opic=974http://forums.planetside.co.uk/index.php?t

Strata and outcrops tutorial by Piliph:








http://flore-de-bourgogne.chez-alice.fr/tuto1/strata.html

ta

sense, but that’s also dependent on the

ard layer steepness and plateau buildup settings.

are fed by a twist and shear shader which ‘push’ or ‘pull’ the strata outwards or

wards.

In excerpt the hard layer depth is the ‘horizontal space’ between the vertical stra

features. Hardlayer spacing is the ‘vertical space’ between the hard layers, thusdetermining the thickness of your strata layers in a

h All strata

in

F

For ‘Strata 1’ the spacing is 15 meters, quite small in relation to the displacementfeatures created by the PF’s, so this will give quite subtle strata ‘horizontal wise’.

The hard layer spacing is 25 meters, in combinati

kind of stair with very short footsteps, so to say.

I wanted to have quite extreme sharp and short edges so I upped theto 2. The higher the value the more ‘vertical’ the hard layer will be.

A low plateau builtup value would result in very flat spacing between the har

I wanted the hard layers to blend into each other better so I increased it toT

ig 8: twist and shear settings for emphasizing the outcropped effect

on with the spacing this will result in a

hard layer steepness

d layers and

6.he result of these settings are shown in figure 9 and is encircled as ‘#1’.



For ‘Strata 2’ I used slightly larger hard layer depth and spacing to get bigger strata.It is fed by a twist and shear with negative lean factor resulting in more ‘retracted’ strata,

so they don’t look that much outcropped. The lower hard latyer steepness and plateau

buildup result in less extreme strata than ‘Strata 1’. The result of these settings areshown in figure 9 and is encircled as ‘#2’.

Finally, for ‘Strata 3’ I used slightly larger hard layer depth and spacing to get biggerstrata. It is fed by the same twist and shear as ‘Strata 2’ The lower hard latyer steepness

and plateau buildup result in less extreme strata than ‘Strata 1’. The result of these

settings are shown in figure 9 and is encircled as ‘#3’.

Result:

Fig 9: result of the strata and outcrops shaders, red circles represent corresponding number of the strata

node in the node-setup so you can visualize their effect.



Chapter 4: further surfacing

Prior to adding the strata there already has been some coloring via the base colour nodes.

I aimed for darker colors that I already had and also wanted to give the rocks a shinylook. In summer dry rock can look really shiny and I wanted to achieve this.

Fig 10: main surfacing nodes



Adding specularity to a surface to get the shiny look can be achieved using a ‘default

shader’ as child layer of your surface layer. Controlling specularity is quite easy, since it

is mostly regulated by 2 parameters which speak for themselves.

Reflectivity determines the amount of reflectivity, the amount of shiny look you want onyour surface. Specular roughness determines the spread of the highlights created by

reflectivity. Low roughness results in small bright highlights while higher roughness givesofter results in more widely spread and softer highlights.For this image I used a reflectivity level of 0,075 and roughness of 0,5 for the surface

layers I wanted to be ‘reflective’.

When you add a default shader as a child of your surface layer keep in mind that the

diffuse color setting of the default shader determines the color of the surface layer insteadof the surface layer’s node self.

Adding PF’s to the color input will add additional color detail.

‘Surface layer 04 and 05’ do have a PF attached to their displacement input. This PF is a

small scale fractal with low displacement values. This creates bumpy details.

The rest of the surfacing aspects speak a bit for themselves and are covered by much

better tutorials☺

Result so far:

Fig 11: just the terrain, cracks, strata and surfacing, a preliminary result I’ve posted before



Chapter 5: adding even more displacement features

A while ago Frank Basinski posted a clipfile showing his way to achieve cracks on fake

stones. His clipfile wasn’t only able to create nice cracks but also nice gashes and ‘rips’.Since I already had nice cracks I was mainly interested in getting some nice gashes and

rips in the rocks and strata.You can find Frank’s topic and explanation about his clipfile here:http://forums.planetside.co.uk/index.php?topic=2009.0

Fig 12: Frank Basinski’s ‘cracks and gashes’ clipfile

What I basically have adjusted in this clipfile is the ‘Size of Voronoi’, ‘Warping the

cracks’, ‘Adjusting the deeper gashes’ and the ‘Make cracks and gashes’.All to fit and match the scales of my project, since this clipfile was optimized for stones

of about 3 meters. I also increased the displacement multiplier settings to match the

increased scales. All the scales and displacements settings were multiplied by around 8 –10 times.





Result:

Fig 13:

Fig 13: a detail cropped from a high-res render showing the specific effect achieved by Frank’s clipfile

Chapter 6: adding ultra-fine detail; sand

In the meantime when I was working on this project there were periods I got fed up withit and I decided to leave it for a couple of days. If you ever get stuck in a complicatedproject and can’t seem to improve it or get up with new ideas…just leave it for a couple

of days or maybe even some weeks. A refreshed look and mind will give you sparks of

creativity. At least, it works fine for me.

During this break I was trying to create a nice looking sand-surface using tiny fake

stones. I went for a simple fake stones stack approach, see figure 14.

This was a straight copy & paste from a project where I intended to create a sunset at a

beach with wet shiny sand ripples (still in progress).

The ‘Shiny Sand Base’ forms the base layer for all the fake stones nodes on top.It controls the slope and height constraints of the sand.

The ‘Sand MicroBump’ node is a PF with small scale displacements to form a very

subtle rough base layer for the fake stone shaders.Each ‘Sand x’ node has a ‘Default shader Sand x’ attached which were intended for

specularity settings. Specularity was not enabled in this scene.

Attached to each ‘Default shader Sand x’ is a PF without displacement.

It only outputs color information.



Fig 14: sand shader setup…

Let’s take a look at the settings in figure 15 on the next page.

All fake stones have the same size, only their density differs. I didn’t want too many dark

tiny stones, so their density is just 0.15. As you can see I increased the density of the

more ‘common’ colored fake stones.As I mentioned before each fake stone has a default shader attached with a PF as color

supplier. The colors in the PF were initially set the same as in the default shader and then

I increased the high color and decreased the low color to create a bigger color range.

The PF scales were set the same as the fake stone scales.

Figure 15 shows an example of a test render showing the sand texture I implemented in

this scene. As you can see the render-quality was not sufficient. Further testing showedthat rendering between quality 1.3 and 1.8 was absolutely necessary to make the best of

it. Render settings are discussed later.



Fig 15: …and the sand shader settings

Fig 16: a pre-viz I made for an other project, showing the sand shaders and also showing the lack of

very high render-quality which is absolutely necessary to get the best result with this method



Chapter 7: lighting & rendering

So finally the scene is ready to be rendered, except for the lighting which should

absolutely not be underestimated.While learning TG2 and its GI I’ve found out that increasing GI’s ‘strength on surfaces’

in the ‘enviroment light’ node creates lighter surfaces and a greater ‘GI feel’ to theimage. See figure 17.

Fig 17: lighting and GI setup

Disadvantages were the increased saturation of coloring so I had to reduce the ‘ color on

surfaces’ and the ‘soft clip effect’ under the ‘effect’ tab of the render node.Soft clip effect can be compared more or less to (color) ‘toning’ of the image.

When an image has a certain dominant color or color semblance reducing the soft clip

effect can be useful.



Another important feature in the lighting setup is the usage of a fill light, although incombination with GI. The fill light ‘Shadow Fill’ doesn’t generate any kind of shadows

or specular highlights. It’s only plain light projected from the opposite side of the main

sun. This light only has a strength of 0.2 which is enough to further lighten up the dark shadows.

Fig 18: render settings and effect settings which are related to camera-exposure

As I mentioned before I increased the camera exposure to 1,35.The reason for this is the decreased ‘Gamma correction’ and increased ‘Contrast’

which generates a slightly darker image.

The render detail was set to 1,5 due to the fake stones sand layers.

Anti-aliasing was set at 16 for the tree-model (Aleppo Pine, Xfrog).GI relative detail and sample quality were set at 2.

Increasing render detail also increases GI quality, so setting it higher than 2 wasn’t

probably necessary. Although I have to admit the image could have used GI set at 3/3 forbest coverage of lighting and GI (see darker triangular shapes in the upper part of the

final render on the front-page or forum).



Chapter 8: final result and conclusion

This tutorial covered many aspects involved in creating this image. As you may have

understood already I’ve been using many clipfiles and techniques learned from otherartists around. Without them, creating this image would have take a lot longer, maybe not

even possible! So thanks to everybody for contributing to the community with these greatclipfiles and thus sharing their techniques and knowledge.

Thanks for downloading this tutorial and the support on the net.

I hope you enjoyed this tutorial as much as I did when I was creating this image.

Martin Huisman

tu-canyon wall tutorial

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