Environment Series 5: Trees



Hey guys, today we have part 5 in the environment series.
This series is based around nature and cycles.

Bear in mind that this is NOT a beginner series,
Of course Beginners will still be able to follow along but be ready to do a bit of googling ;)

So the theme is: “Environments”

So we will be doing a 8 part series on modelling an environment scene, you may have already seen the teasers on facebook, but if not you can jump there now :D
facebook.com/cgtutorials
So why so many parts for one scene?
Well basically this is going to be reference material, so you can just jump to a section you need to refresh on.
What will be covered?

1. Landscaping: The ground, path, river, and background
2. Grass: The grass, flowers, and butterflies
3. Bridge: The old bridge
4. Well: The old Well
5. Trees: All the Trees
6. House: An old fashioned cottage
7. Ivy: We cover everything in Ivy
8. Finish: Touch-ups, Compositing etc

So Lets get started, For this tutorial you will need a current cycles build from graphicall.org.
In this part we will be looking at creating trees in cycles, also we will look at quick ways to optimize the trees so they will render on slower computers.
We will also look at texturing trees in cycles to get the look we want.

NOTE: Ok so some things have changed since part 4, For some reason all my shaders refused to work (they actually managed to make my monitor look like an old tv with no reception)
This is part of the reason I procrastinated getting this tutorial done for so long.

Sooo, I have re done the shaders and it looks about the same, feel free to download the file if you want to inspect anything.
One thing I did change is the grass shader, It is now just translucent with an alpha channel.
I have been informed that glass shaders slow down the render a LOT, so out they go for grass, the translucent grass is just as good anyway :)

So let’s get started!

1. Creating the Tree

We are creating trees, so turn on the sapling addon, And on a new layer add in a curve->Tree
There is an excellent tutorial by David Ward on creating trees here
There is also another good one on Blender Nerd I believe,
Anywho, The shape of the tree is entirely up to you, I used a bevel resolution of 3, 3 levels of branch splitting, 0.3 base size (where the braches start)
And for the leaves I have 40 leaves with a scale of 0.2 and x-scale of 0.5
This gives us a standard tree withlots of tapered leaves.
Do note however
that it is best to craete more leaves than you think you need, it’s much easier to delete leaves than add them in.

2. Preparing the tree

Now we have made our tree, we need to convert it all to polygons so we can begin texturing.
Select all the trunk(s) and branches and convert them from curves to polygons with “Alt+C”.
Now make sure you UV unwrap your tree, UV-Unwrap the trunk and automatic unwrap the branches. we won’t see the branches much so no point spending a lot of time on UV’s.
You don’t need to keep to within the UV bounds as we will be using a tileable texture.
The leaves are already unwrapped by the sapling addon

3a. Texturing the branches

Let’s create a new shader for our branches, make it display brown in the viewport so we can easily see it, and bring a tileable bark image into a diffuse shader.
Go into shaded viewport (Alt+Z) and you will get an idea of the mapping of the texture, scale it around in the UV editor to get the right scale.
I am using a texture from the nature academy bark pack, but there is plenty of textures available on cgtextures that are free to use.

3b. Texturing the branches

Now we will use a simple shader for our branches, connect your image texture through a HSV node so you can tweak to colour to your preference, then to the color value of the diffuse shader.
For the bump map, we will take the same image, pass it into a BW node as cycles prefers black and white for bump, then we use a color ramp to pinpoint the values we want it to bump, and finally we use a multiply node to tone down the bump.

4. Texturing the leaves

Everyone seems to texture leaves differently. This is a way that works for me, which is quite different to some of the other ones I have seen, but makes more sense to me personally.
Add in two translucent shaders nodes, one is a medium green, and the other a light yellow. Mix these together with a Layer weight – facing, set to 0.6 for the factor value.
This will cause some leaves to be a lighter green, this looks more realistic as if you look at a leaf, the bottom is lighter, so we are simulating this as if we can see the bottom of some leaves.
Now blend that mix together with a glossy shader node with a very light yellow, and use a fresnel node set to 1.125 for the factor value. This is our specular mix.
And that is our tree done!

QUICK TIP:
Change the colors to a burgandy and orange-yellow and it will give you a very nice autumn look.

5. Placing the trees

Now we have a tree, instance them around the area a little, and give them a little rotation and scale variation, we instance as it improves render times significantly, however feel free to add in some tree variations.
Finally hit render and you should have something like below :)


So I hope you enjoyed this tutorial, and stay tuned for part 6 where we look at building an old fashioned cottage!

Got stuck? Leave a comment below

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  • Jimmy Nilsson

    Do you have any plans to update these now that cycles supports strand rendering?
    Also, when is part 6 coming? Or have i just missed it? :P