Blender 3D: Noob to Pro/Advanced Tutorials/Advanced Rendering

= Alternative Renderers =

You previously learned about the Blender Internal renderer. This is the old, original renderer that was included from the earliest days of Blender. However, it is not the only way to render scenes created with Blender.

Cycles
Beginning with Blender 2.61 came the new Cycles renderer. Its most important new feature is more physically-accurate handling of lighting in the form of global illumination. What this means is that Cycles automatically implements subtle indirect-lighting effects, where light can bounce off a diffuse surface and provide some illumination to other diffuse surfaces nearby. And it doesn’t distinguish in its lighting calculations between “lamp” objects and non-lamp objects which have “emissive” materials; in Blender Internal, the latter do not provide any light to other objects, whereas in Cycles they do.

Cycles also offers high-fidelity previews in the interactive 3D view. As it continues to be developed, it will perhaps replace the old Blender Internal renderer someday, but not all the features are there yet for this to happen.

See also:
 * Manual on Cycles.
 * Andrew “BlenderGuru” Price’s Introduction to Cycles.

Freestyle
This is not a complete renderer in itself, but a new addition to the Blender Internal renderer in version 2.67 of Blender. It adds sophisticated options for accentuating edges to produce cartoon-like renders.

See also:
 * Manual on Freestyle.
 * Report by Libre Graphics World on the origins of Freestyle.

External Renderers
There are also a great number of stand-alone renderer programs, both proprietary and Free Software, around (e.g. Aqsis, LuxRender, Octane, RenderMan, Yafaray). These have no capability to create or edit 3D models or scenes, they are designed purely to perform rendering on already-created models and scenes. Several of them—particularly the Free Software ones—are supported by addons to allow them to work with Blender almost as conveniently as its built-in renderers.

= Disadvantages of Other Renderers = Of course, there can be a downside or two to choosing a renderer other than good old Blender Internal.

Say Goodbye to Your Materials and Lighting
One important thing to note when constructing models is that materials and lighting are renderer-specific. If you have painstakingly set up transparent materials and bump maps and all the rest of it, then decide to switch renderers, you will have to do that work all over again. And you may find that there is no exact one-to-one correspondence between particular features of Blender Internal materials and lights and those supported by the alternative renderer, so you will have to find approximate workarounds.

Of course, the actual geometry of your models remains unaffected.

High-Quality Renderers Are S-L-O-W
If you are accustomed to hitting and seeing an image appear after just a few seconds with Blender Internal, using one of these other renderers will likely come as a shock. To get a good-quality render can easily take 10-100 times as long as with Blender Internal. You can speed things up by choosing lower-quality settings, but then the results tend to be filled with noise and not fit for much more than preview purposes.