Graphics Reference
In-Depth Information
By switching the Emission node connection to the first Mix Shader input socket, it's obviously
possible to invert the direction of the light emission.
Using volume materials
Very briefly (because there are dedicated recipes in the last chapter of this Cookbook), let's
take a look at how volumetric materials work in Cycles.
Volumetric materials are exactly what they sound like. Instead of the surface of an object,
Cycles renders the inner volume of that object, and this gives space to a lot of interesting
possibilities—not only can elusive materials such as smoke, fire, clouds, or light transmission
effects through the medium be realized, but peculiar shapes can also be obtained from the
volume itself by Boolean operations made through material nodes.
The drawback is that volume materials are slow—a lot slower compared to the surface
materials, but hopefully, this is an issue that will be fixed in some way in the future
(be aware that from Version 2.72, volume materials are available on GPUs too).
Getting ready
Let's start with our usual Spheroid blend file:
1.
Open the
start_02.blend
file and delete the material assigned to the Spheroid.
2.
Put the mouse cursor in the 3D view and press
Shift
+
Z
to navigate to the
Rendered view.
3.
Click on the New button to add a new material, and then switch the Diffuse node
link from the Surface input socket to the Volume input socket of the Material
Output node.
How to do it...
Now let's go to the volume section of the Material window with the following steps:
1.
Go to the Material window under the Properties panel, and click on the
Diffuse BSDF labeled button to the side of the Volume item. In the pop-up
menu, select the Volume Scatter node as shown in this screenshot:
