Based on Solid Angle's technology, a leader in production ray tracing, Arnold 5 is expected to provide a productive rendering environment for artists worldwide. In addition to offering various feature updates, it introduces a transition to a new architecture prepared for future content environments. Through core Arnold updates, faster rendering, new features, and enhanced workflows, it helps artists produce exceptional visuals.

The core of Arnold technology is a powerful C++ Application Programming Interface (API) that allows users to create custom tools, such as shaders, geometry procedures, and transformation plugins for major DCC tools. The C++ API in Arnold 5 has been restructured with the removal of legacy features, and through extensions and simplifications, it makes writing new Arnold-based applications easier, enabling faster and more consistent code. Additionally, Arnold 5 introduced a decoupled shading API and a BSDF API that relies on closures. Internally, all of Arnold's built-in shaders now rely on closures.


Melanin content reduction effect of the new Standard Hair Shader (Image source: Zeno Pelgrims)


Comparison of the existing and new samplers in quad and disk lighting represented by samples/pixels

Arnold 5 features several sampling optimizations. New 2D dithered sampling improves the visual dispersion of noise at lower sample rates, significantly enhancing sampling results for soft shadows, indirect lighting, and depth of field. Direct lighting sampling has been redesigned for quad, disk, and cylinder lighting to reduce noise in surfaces and volumetric lighting. Improved indirect lighting rendering also significantly shortens the speed of indoor scenes.

Arnold 5 features new built-in shaders such as Standard Surface, Standard Hair, Standard Volume, and Utility that are accurate and allow artists to expand the boundaries of realism through rendering.


A new standard volume shader has been applied (Image source: Lee Griggs)

Shaders for Arnold 5 can be written in C++ as well as Open Shading Language, an advanced shading language for production GI renderers. OSL shaders placed in the shader search path are automatically registered as Arnold shader nodes, and their parameters are converted into Arnold parameters.

Light Path Expressions are used to extract specific lighting components and create separate AOVs. In addition to the existing simple shader-specific AOV definition mechanism, you can define AOVs of various layers using direct and indirect lighting and general expression syntax within individual shaders to define all the points of contact, such as light scattering and reflections in the scene, that need to be written in each AOV.

Arnold 5 natively supports synColor and OCIO to better handle input (texture) and output (rendered image) color conversions, and can be extended with custom color manager nodes to perform all internal calculations more easily and accurately in radial linear space.