Blender is free and open-source 3D computer graphics software, commonly used to create and animate 3D models, or to edit videos.
There are many additional features that can be enabled via USE flags, and some of them are explained a little more in-depth later on in this article.
USE flags for media-gfx/blender 3D Creation/Animation/Publishing System
||Build for OpenVDB ABI 6.|
||Build for OpenVDB ABI 7.|
||Add support for Alembic through media-gfx/alembic.|
||Enable Bullet (Physics Engine).|
||Add support for Collada interchange format through media-libs/opencollada.|
||Enable color management via media-libs/opencolorio.|
||Build cycles renderer with nVidia CUDA support.|
||Build cycles renderer (requires media-libs/openimageio and dev-libs/boost).|
||Adds DDS textures support to Blender.|
||Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces|
||Build C and Python API documentation directly from the source code.|
||Adds surface fluid simulation to Blender using El'Beem library.|
||Enable ffmpeg/libav-based audio/video codec support|
||Use FFTW library for computing Fourier transforms|
||Build without graphical support (renderfarm, server mode only).|
||Add support for the JACK Audio Connection Kit|
||Use dev-libs/jemalloc for memory management|
||Support for JPEG 2000, a wavelet-based image compression format|
||Enable features depending on llvm.|
||Build and install man pages.|
||Enable NDOF input devices (SpaceNavigator and friends).|
||Add Native Language Support (using gettextGNU locale utilities)|
||Add support for the Open Audio Library|
||Allow OpenCL Graphics Acceleration. This may require extra graphics card drivers.|
||Support for the OpenEXR graphics file format|
||Enable OpenImageIO Support|
||Build support for the OpenMP (support parallel computing), requires >=sys-devel/gcc-4.2 built with USE="openmp"|
||Add rendering support form OpenSubdiv from Dreamworks Animation through media-libs/opensubdiv.|
||Add GPU preview rendering. Only works with nVidia cards.|
||Add support for OpenShadingLanguage scripting.|
||Add support for Simple Direct Layer (media library)|
||Add support for libsndfile|
||Build the standalone version of Cycles.|
||Use the system numpy implementation rather than a local copy.|
||Use the system python implementation rather than a local copy.|
||Use threading building blocks library from dev-cpp/tbb.|
||Build the provided unit tests.|
||Add support for the TIFF image format|
||Add support for memory debugging using dev-util/valgrind|
emerge --ask media-gfx/blender
To test what unstable packages an unstable version might need, making use of the
--autounmask=y --autounmask-writeemerge options can be helpful in populating a list for further review.
This section lists many of the optional features available in blender and gives a brief overview of their use for beginning users.
Audio device support
Support for Jack, OpenAL, or SDL audio can optionally be enabled through their respective USE flags.
Inside Blender, go to the Edit->Preferences->System tab and set the Audio Dev to the desired setting.
Cycles renderer can work on GPUs, for example Nvidia GTX 970 is about twice as fast as an i5 4690k on traditional BMW benchmark.
To enable graphics card rendering with Nvidia graphics cards, install Cuda:
emerge --ask --verbose dev-util/nvidia-cuda-toolkit
Inside Blender, go to the Edit->Preferences->System tab and set Compute Device to CUDA and select the graphics card in the box below. If the graphics card is not supported these options will not be visible.
Now set the renderer to Cycles Renderer and in the renderer panel under the Render options set the Device to GPU Compute.
The first time a render is created with a new version of blender, the CUDA kernels will need to be compiled. This may take over 15 minutes.
File format support
Support OpenCOLLADA (.dae), jpeg2k, sndfile, and tiff image file formats can optionally be enabled through USE flags.
collada USE flag adds entries to File->Import/Export for Collada (Default) (.dae) files.
The others can be used with background images in the properties panel of the 3D View or as output formats in the render panel.
Blender should work with either ffmpeg or libav libraries, although only ffmpeg is officially recommended by the Blender developers.
Headless (server only)
For render farms it is possible to compile blender with the
headless USE flag. This is not recommended for most users.
This feature reduces the Blender file size by around 5 MB, but it will not be possible to run blender normally as the GUI is not available.
In headless mode, Blender can still be used to run python scripts from the commmand line:
user $ blender -b -P script.py [-- [--optionsforscript .. ] ]
This functionality is also available with regular versions of Blender, it is not necessary to enable the
headlessUSE flag to run scripts from the command line.
It is recommended to enable
jemalloc to use a more efficient memory allocator. This reduces wasted memory during rendering and allows for larger scenes to be rendered.
Support for memory profiling can be enabled using the
valgrind USE flag. See Debugging for instructions on setting up Valgrind.
Open Colorio provides additional options under the Color Management section of the Scene panel.
Inside Blender, select the Render View and Look options, and adjust the exposure, gamma, and curves to obtain the desired look.
Opensubdiv is a set of libraries that improve subdivision surface modifier evaluation. This can dramatically improve the frame rate of viewing animations in the viewport when using high levels of subdivision.
Not all cards are suitable. The current code checks for geometry shader, GL_ARB_gpu_shader5, glProgramParameteri, glProgramParameteriEXT, and glProgramParameteriARB. These are available as part of OpenGL 3.2, 4.0, and 4.1, or as extensions.
The only way to use a subdivision surface modifier is to enable the
opensubdiv USE flag.
OpenVDB provides a data structure for storing and manipulating volumetric information efficiently. It can be compiled into blender using the
openvdb USE flag, and
openvdb-compression is also recommended as the data can require upwards of 20MB.
In Blender, set the renderer to Cycles Renderer. Go to the physics panel and enable physics for Smoke. In the smoke section select Domain. Save the file to enable editing of the smoke cache. Change File Format to Openvdb and select Blosc compression if desired. Now create and bake the simulation.
- OpenCL — a framework for writing programs that execute across heterogeneous computing platforms (CPUs, GPUs, DSPs, FPGAs, ASICs, etc.).
- Project:Artwork/Artwork: Gentoo artwork, including a .blend file used to create some of it.