Thursday, October 29th, 2020 Posted by Jim Thacker

Autodesk ships Arnold 6.1

Autodesk has released Arnold 6.1, the latest version of the VFX-industry-standard production renderer, adding a new framework for post effects and for rendering physically correct nested dielectrics.

The update also adds support for partial texture loading in Arnold GPU, and initial support for light linking; plus support for light shapes within USD scenes.

The integration plugins for 3ds Max, Cinema 4D, Katana and Maya have also been updated.

New set of imagers nodes for applying post-effects to interactive and final-quality renders
Arnold 6.1 introduces a new framework for applying post effects to renders, adding a new set of ‘imagers’ nodes to modify images before they reach the output driver.

In the initial implementation, there are five imagers, for tonemapping images, and applying colour corrections, lens effects, and exposure and white balance adjustments.

Imager nodes can be chained, and can be used during both final-quality and interactive rendering, although currently it is only possible to edit existing imagers during IPR, not add new ones.

New priority system in the Standard Surface shader for physically correct nested dielectrics
The update also introduces a new system for rendering nested dielectrics, where adjacent transparent materials, such as water within a glass container, are modelled as overlapping volumes.

Arnold’s Standard Surface shader now includes a dielectric priority property, which enables artists to control which material within a region of overlap determines dielectric properties like index of refraction (IOR).

Unlike the legacy mode – still available by setting a global property – the new system correctly calculates light refraction at boundaries between materials.

Support for partial texture loading reduces memory usage in Arnold GPU
GPU renderer Arnold GPU gets support for partial texture loading, reducing memory use when rendering scenes with tiled or mipmapped textures, such as those in .tx format.

Autodesk says that in a typical scene, the amount of memory needed for textures “could be … up to 5x smaller”, although the reduction in overall GPU memory usage is smaller.

In the scene shown in the documentation, overall GPU memory usage is 2.2x lower in Arnold 6.1 than in Arnold 6.0.2.

Other changes to Arnold GPU include support for light AOV groups within light path expressions, and initial support for light linking: currently, it isn’t supported on volumes.

Updates to USD support and overall render performance
The update also builds on the initial support for Universal Scene Description-based production pipelines begun in Arnold 6.0, with the Arnold USD procedural now supporting the UsdLuxShapingAPI.

In the current release, that means that spot and IES lights are supported within scenes in USD format.

The Hydra render delegate, which enables Arnold to run as a viewport renderer within applications like Katana or Solaris, now supports per-face material assignments and the UsdTransform2d preview shader.

In addition, there are a range of performance improvements, particularly on Windows: Autodesk says that Arnold now “runs on average 7-8% faster overall” on the operating system.

There are also individual improvements to interactivity in IPR renders, and when using adaptive sampling.

Integration plugins for 3ds Max, Cinema 4D, Katana and Maya also updated
Most of the integration plugins for DCC software have been updated, with MAXtoA 4.2 for 3ds Max, C4DtoA 3.2 for Cinema 4D, KtoA 3.1 for Katana and MtoA 4.1 for Maya all supporting the features added in Arnold 6.1.

At the time of writing, only Houdini integration plugin HtoA does not support the new features.

System requirements and availability
Arnold 6.1 is available for Windows 7+, RHEL/CentOS 6+ Linux and Mac OS X 10.11+. Integrations are available for 3ds Max, Cinema 4D, Houdini, Katana and Maya, and there is a legacy plugin for Softimage.

The software is rental-only, with single-user subscriptions starting at $45/month or $360/year. Multi-user subscriptions start at $630/year. The plugins are free.

Arnold GPU is supported on Windows and Linux only, and requires a compatible Nvidia GPU.

Read a full list of new features in Arnold 6.1 in the online documentation