If you’ve been to the Blender forums recently, you’ll know that quite a few people are a buzz with new hair rendering feature of Blender Cycles.
On December 9 2012, the first hair renders started appearing online, and since then it’s grown from an experimental feature, into something stable. In fact, hair rendering will be included in the next official Blender release: 2.66, which is due out in the next week ;)
So what better time to get into it?
Hope this tutorial was useful!
Create something cool from this tutorial? Post it in the comments below.
Not a fan of videos? Here’s the full text version:
This tutorial is all about taking a previously made model with hair, and making it work with Cycles.
Learning how to render hair has more uses than you may think. Whether you’re an architect or a character animator, you’ll probably be called upon to use strand rendering at some point.
This phenomenal hair render was made with 3ds max. Can you top it?
The old way of rendering strands entailed a lot of button pushing, certain lamps, fiddly textures and aligning of the planets to make it work.
The new method is simpler, faster to set up and produces more realistic results.
Kick open the starter file and you should see Sintel, posed and ready to render with only the hair needing materials:
With the hair selected, go to the particle panel and scroll down till you see the Cycles Hair Rendering settings:
If you don’t see those options then:
The first thing we’ll look at is the hair rendering modes:
The modes on the left side are faster to render but lower quality, and the modes on right side are slower to render but higher quality:
If you aren’t sure what to pick, stay with the default mode: True Normal. It offers the best results for most scenes. Change modes depending on how close the camera is to your subject.
Now lets move onto the next setting: Shape.
The shape setting defines how quickly or slowly the width of the hair strand will taper off:
For human hair, you should use something in the negative value.
We’ll use -0.8:
Next are the Root and Tip values. These are quite simply the width of the hair at it’s Root and Tip (duh).
For some bizarre reason the default value for Root is 1, which will give you strands almost as big as Sintel’s head. A more reasonable value for hair is 0.002:
Leave Tip as 0, since we want the hair to taper down to 0 width.
Add a new Material and name it Hair. You may also wish to set the preview to Strand mode (and also let out a mighty hoorah for the introduction of preview capabilities).
Thankfully, you don’t need to relearn materials for the sake of strands, since the strand’s materials work the same as any other object in Cycles.
Switch to the Node editor. To get hair shiny we’ll add a Glossy shader node and connect it to the default Diffuse shader, using a Mix node. Set the values as shown:
Now let’s give the hair some color. We’ll be using the hair texture that comes bundled with Sintel:
Add an Image texture node and load in the hair texture, then connect it to the Diffuse Shader node:
You should now get this noisy mess:
…but at least you can see that it’s working :)
Now to make her a red head.
Add an RGB Curve (which is another new feature!) between the Image texture and Diffuse Node. Click the R (red) channel and give it a slight hump:
Finally, we’ll give the hair some translucency so that light can pass through it.
Add a Translucency node and connect it to the RGB node:
Next add an Add Shader node and connect it between the Translucent Node and the final Material node.
You should now have hair that would make a balding man weep.
In certain circumstances, it may be necessary to have the hair fade out. Generally this isn’t good for human hair, but it’s great for fur.
1. Using the node setup from above, add a Transparent node and connect it with the output from the Add shader, using a Mix node:
2. Next add in a Hair Info node and connect the Intercept output to the Fac input of the Mix shader:
The Intercept acts to alter the material along the length of the strand (like this).
Here’s a before and after from a different scene:
And if that’s a bit extreme, you can add a ColorRamp between the intercept and mix node for added customization.Close Summary