Release Date


  • Many rendering optimizations in Arnold 4.2 including faster ray accel build, subdivision, displacement, polymesh processing, rendering of many-light scenes, backlighting, SSS, image shader and deep output.
  • Improved quality in motion blur sampling and indirect specular sampling.
  • Smoother bump near shadow terminator and reduced edge darkening in Cook-Torrance BRDF.
  • The Standard shader can now output refraction opacity as an AOV. It is advised to write the complete RGBA set of channels, since the alpha component will constitute a mask that can be used to mix it in with the regular opacity, multiplying in refraction opacity to regular opacity based on the mask.
  • Support for Custom shutter shapes.
  • Support for Rolling shutter.
  • trace_set shader implemented.
  • ICE improvements: Hierarchies can be shape-instanced and texturable rectangular ICE shapes.
  • sib_texture2d_grid, txt2d-grid shaders and Factory Modulus Shader implemented.


  • This will be the last version supporting Softimage 2012.
  • We are statically linking OIIO in Windows, the same way we were doing in Linux and OSX.
  • Photometric IES files are now searched for in texture_searchpath.
  • Removed the AutoTransparency Mode.
  • The low_light_treshold and camera exposure parameters from the Arnold core have been exposed in the SItoA UI.
  • "Use Autobump in SSS" checkbox added in the sampling tab to control whether displacement autobump is taken into account when computing sub-surface scattering.
  • skin_sss has been removed.


  • Removed cubic format from the sky and skydome light.
  • Removed specular_brdf from standard shader: Since the Cook-Torrance is similar in performance to the Ward-Duer BRDF yet superior in quality due to its reduced edge darkening and higher energy conservation, the specular_brdf parameter has been removed from standard, leaving Cook-Torrance as the default (and only!) BRDF of the standard shader. Therefore, the look of existing standard shader-based materials that use the anisotropic Ward-Duer BRDF might change a little bit for the better.
  • Removed the lens shaders defining the camera type; this is now done in the camera options property. We have also moved the DOF controls here as well, so DOF can be enabled per camera.
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