A feature that you will often hear people asking about in Cycles is the possibility to distribute a render between multiple network computers. Since Cycles works with threads to render still images, it makes a lot of sense to get different each one of those threads rendered by a different computer.
Other render engines allow that kind of distribution for render, but Cycles doesn't have that feature yet. Rendering an animation using multiple computers works great, but only for full images. Each computer will work on a single frame.
You will find distributed rendering in the roadmap for future releases of Cycles, but nothing available today. Not officially, at least.
What if I told you that part of the code for distributed network rendering with Cycles is already present in Blender today? The code is there but disabled by default.
A developer called fjuhec found that code and made a “special†version of Blender, which gives access to the distributed network rendering with Cycles. He calls that custom build Blender pigeon.
Here is a screenshot of the distributed network rendering feature.
Image credits: fjuhec
The primary purpose of Blender pigeon is not to give access to that particular feature. You will find several other tweaks and changes.
Here is a link to download Blender pigeon, which uses Blender 2.78 as a base. You can try the distributed network rendering with Cycles using Blender pigeon.
The existence of a disabled feature in Blender probably means that it is either unstable or not working properly. Don't expect a completed feature. Make tests to evaluate if it might suit your needs.
As a precaution, it is always wise to backup any important files before dive into experimental, unfinished features in Blender custom builds.
