[Bf-cycles] Roadmap / Focus

[Brecht Van Lommel]

Hi all,

There's been some discussion about what the focus of Cycles should be,
let me try to clarify. Cycles is supposed to be a render engine for
individuals / small studios, aimed primarily at rendering animations.
This goal is what I evaluate priorities of features by.

For the next few months, my main priorities are:
* Render layers, passes, full sample, compositing layer, ..
* Performance improvements / noise reduction for typical two bounce
animation scenes
* Some smaller things for completeness (blender integration stuff,
ramps, multi GPU, ..)

After that, we should get to some more exciting features, which ones
are a bit unclear, but this will be influenced by Mango. Volume
rendering and motion blur seem like good candidates, but we'll see.
Performance work will be ongoing during Mango of course, and I see
that quite broadly, it's about low level performance tuning, better
algorithms and better user control.

Beyond that, this is roughly what I'd like to see added over the next 2 years:
http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/ToDo

There are some things obviously missing that people would like to see
added. Bidirectional path tracing, photon mapping, MLT and similar
algorithm are not a priority for me, since I do not believe they are
the main possible performance improvements for animation frames.
Shading language support, resumable rendering ,  is another one that I
do not think should get very high priority.

Lastly, GPU rendering can be somewhat of a bottleneck to development.
It seems that with older cards and current OpenCL support in the
drivers, we'd have to considerably complicate the code to get Cycles
working fully, to the point where it would be too hard to add new
features. This also means we're dependent on improving driver
implementations or language features. I'll keep track of this, but
also can't justify spending too much time on this, to try to work
around issues with every possible card / driver combination.

Thanks,
Brecht.