Cycles Render Engine
====================

Cycles is a ray tracing renderer focused on interactivity and ease of use, while
still supporting many production features.

= Building =
------------

== Requirements ==
-------------------

Crucial dependencies:
- OpenGL
- GLEW
- Boost (version at least 1.48).
- OpenImageIO (plus all the libraries which OIIO depends on).
- PugiXML unless OpenImageIO is compiled with embedded version of this library.

Optional dependencies:
- OpenShadingLanguage

== Precompiled libraries ==
---------------------------

It is possible to use precompiled libraries for OSX and Windows The libraries could
be checked out from Blender's library repository:

  https://svn.blender.org/svnroot/bf-blender/trunk/lib/

Currently the full checkout of platform libraries is required. This means, i.e.,
to use OSX libraries this folder is to be checked out:

  https://svn.blender.org/svnroot/bf-blender/trunk/lib/darwin-9.x.universal/

Build system expects precompiled libraries to be stored in the lib/ folder next
to folder with Cycles sources.

== Compilation Options ==
-------------------------

- WITH_CPU_SSE                  // Enable SIMD instruction if they're detected on
                                // the host machine.
- WITH_CYCLES_STANDALONE_GUI    // Build standalone app with GUI.
- WITH_CYCLES_OSL               // Build with OpenShadingLanguage support.
- WITH_CYCLES_LOGGING           // Build with logging support.
- WITH_CYCLES_DEBUG             // Build with extra debug capabilities.

== Compilation ==
------------------

Once all the requirements are met, either invoke `cmake` with all desired
parameters from a build folder, or simply type `make` in the root directory of
Cycles repository.

== Extra Dependencies ==
------------------------

Depending on how the dependencies were compiles it is possible that manual tweaks
to the linker are required.

For example if OpenImageIO is compiled as a static library it'll be required to
pass all the OIIO dependencies to the linker using  CMAKE_EXE_LINKER_FLAGS CMake
variable.

Dealing with such kind of dependencies is not really possible automatically, so
we can't reduce entropy of a hassle here.

It is possible to pass CMake configuration arguments to GNU Makefile, i.e.:

  make BUILD_CMAKE_ARGS="-DBOOST_ROOT=/opt/lib/boost"

= Examples =
------------

The repository contains example xml scenes which could be used to test Cycles
render engine.

Example usage:

  ./cycles scene_monkey.xml

You can also use optional parameters (see ./cycles --help), like:

  ./cycles --samples 100 --output ./image.png scene_monkey.xml

For the OSL scene you need to enable the OSL shading system:

  ./cycles --shadingsys osl scene_osl_stripes.xml

= Known TODOs =
---------------

- Installation target is not tested and would need more work.
- Compiled .oso files are not put to the final location, so manual copy is
  required for now.

= Problems =
------------

If you encounter problems, please mail the blender's mailing list bf-cycles:

  http://lists.blender.org/mailman/listinfo/bf-cycles

or ask for help on

  irc://irc.freenode.net/blendercoders