Autodesk has released an updated to Arnold, with Arnold 6.1, boasting new feature improvements, including new post-processing nodes for creating exposure, color correction, and vignetting effects and support for nestled dielectrics for rendering realistic overlapping surfaces, such as bubbles or ice cubes in a drink.
Building on Arnold 6, this update also introduces a number of USD enhancements and brings even more speed and flexibility to GPU rendering with improvements to on-demand texture loading and support for light linking, light AOV groups, and more.
New post-processing nodes, or “imagers,” have been added to allow chaining of pixel effects before reaching the output driver, so users can get their render looking just right. New imagers in this release, include:
Exposure: Specify additional exposure compensation.
Color Correction: Adjust saturation, contrast, gamma, gain and offset for the whole luminance range, or only for shadows, midtones, or highlights.
Lens Effects: Apply optical lens effects like vignetting.
White Balance: Correct your image's white balance with reference illuminants, custom colors, or a blackbody temperature.
Tonemap: Artistically modify your image's tone mapping using a filmic or a modified Reinhard curve.
Autodesk has also added nestled dielectrics, a new priority system for overlapping transparent objects. By allowing users to assign priorities to models, this new feature gives scenes more physically accurate reflections and refraction of rays. This allows for more realistic renders of scenes such as glass containers with liquid contents and bubbles or ice cubes.
In addition, the GPU renderer can now partially load textures which means bigger savings on both memory consumption and rendering time. In a typical scene, the amount of memory needed for textures is now up to 5x smaller. Other GPU enhancements introduced in Arnold 6.1 include support for light linking and light AOV groups, enhanced OSL JIT compilation performance, and improved thin-walled sampling.
This release also adds the following USD improvements:
Light shaping: The procedural now supports the UsdLuxShapingAPI, allowing the use of spot and IES lights.
UsdTransform2d: The render delegate now supports the UsdTransform2d preview shader.
Per-face material assignments: The render delegate now supports per-face material assignments.
Render stats: The render delegate now returns render stats via GetRenderStats. This can be used to show render progress in Solaris.
Schema for custom procedurals: The schemas now include ArnoldCustomProcedural for describing custom procedurals.
Schema updates: Schemas now support cameras, render settings, and new output types.
Parent scope: There is a new flag to specify a custom root for all exported prims.
ST for texture coordinates: Texture coordinates are now written as primvars:st to match the USD convention.