Stable Features


  • Highly scalable multithreaded rendering
  • Backward path tracing, with or without next event estimation (explicit direct lighting)
  • Forward path tracing (light tracing) with next event estimation
  • Stochastic Progressive Photon Mapping (paper)
  • Distribution ray tracing
  • Progressive, interactive rendering (video)
  • Multipass rendering
  • Camera motion blur with arbitrarily many transforms (image 1, image 2)
  • Ray traced deformation motion blur with arbitrary many motion segments per object (image)
  • Image-based lighting
  • Multiple Importance Sampling (image)
  • Render layers
  • Up to 16 AOVs per render
  • Pixel reconstruction filters (Box, Triangle, Gaussian, Mitchell-Netravali, Cubic B-spline, Catmull-Rom, Lanczos, Blackman-Harris)
  • Texture cache with user-settable memory limit
  • Fully spectral rendering pipeline (31 equidistant channels in the 400-700 nm range)
  • Automatic, on-the-fly color space conversions
  • Automatic, on-the-fly gamma / inverse-gamma correction of textures and output frames (linear workflow)
  • Per-object instance ray bias to overcome "shadow terminator" problems
  • Fractional sample counts for direct lighting and IBL in the distributed ray tracing and path tracing engines


  • Pinhole camera
  • Thin-lens camera (depth of field)
  • Spherical camera (to render latitude-longitude environment maps)
  • Perfectly diffuse and perfectly specular BRDF
  • Ashikhmin-Shirley BRDF (image)
  • Kelemen BRDF (image)
  • Microfacet BRDF with Blinn, Beckmann, Ward and GGX microfacet distribution functions
  • Perfectly specular BTDF with Fresnel reflection (image)
  • BSDF Mix
  • Thin translucency (similar to VRay2SidedMtl)
  • Perfectly diffuse EDF
  • Cone-shaped EDF
  • Point lights
  • Spot lights with smooth falloff and gobo support
  • Directional (infinite, parallel) lights
  • Mesh lights (any geometry can emit light)
  • Preetham physically-based day sky model (paper)
  • Hosek & Wilkie physically-based day sky model (paper)
  • Physically-based sun model
  • Latitude-longitude environment maps
  • Mirror-ball environment maps
  • Powerful geometry instancing (with per-instance materials)
  • Bump mapping
  • Normal mapping, Y/Green or Z/Blue up (video)
  • All inputs can be texture-driven
  • Support for CIE XYZ, linear RGB, sRGB and spectral color spaces
  • Support for non-physically-based surface shaders
  • Support for mixed physically-based / non-physically-based rendering


  • Image/texture formats: OpenEXR, PNG
  • Geometry formats: Alembic, Wavefront OBJ, BinaryMesh (proprietary, compressed binary format)


  • Complete C++ API
  • Complete Python API (compatible with both Python 2 and Python 3)


  • XML-based project and settings files with well-defined grammar using industrial-strength parser & validator
  • Parsable logs with standard-compliant UTC timestamps
  • Clean, modern, portable C++ code with strong emphasis on correctness, speed and readability
  • 1000+ unit tests, using a modern C++ unit testing framework (image)
  • Stable, cycle-accurate unit benchmarking framework with performance historization and visualization
  • CMake-based build system
  • Fully cross-platform, available on 64-bit Linux, Mac OS X and Windows

Applications and Tools

  • Command-line interface with optional coloring (image)
  • Qt-based GUI application for interactive rendering, scene composition, inspection and debugging (image)
  • mayaToAppleseed (full integration of appleseed into Maya 2012/2013, C++) (video)
  • mayaseed (Maya-to-appleseed translator, Python/C++)
  • Blenderseed (Blender-to-appleseed translator, Python)
  • Full-featured devkits with prebuilt libraries for Windows/Visual Studio 2012
  • Python scripts to build a robust render farm over Dropbox
  • Many additional command line tools and Python scripts for mesh format conversion, project file upgrade, batch render, etc.

Experimental Features

  • Support for the Open Shading Language
  • Support for geometry that does not fit in memory
  • Fast voxel-based ambient occlusion
  • Fast voxel-based volumetric smoke shader
  • Fast, non physically-based subsurface scattering shader (image, image)