Release Date

April 12, 2017

This version uses the Arnold core. 


MtoA 2.0 is based on Arnold 5. This version contains major changes. It is not backwards compatible with older scenes. An Arnold 5 FAQ is available here. 

New Shaders:

Older shaders like aiStandard and aiHair are still supported but considered deprecated (and don't appear in the hypershade list of nodes). It is possible to replace old shaders by new ones in the shading tree, through the menu "Arnold -> Utility -> Convert Deprecated Shaders". This preserves the shading tree connections, but doesn't guarantee that the look of the old shader will be preserved.

Improved Sampling:

Open Shading Language (OSL):

Shaders can now be written in both C++ and 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, with their parameters converted to Arnold parameters. Once loaded, they can be inspected, instantiated and linked in exactly the same way as C++ shaders. OSL shaders can be used to implement anything from simple texture patterns to full materials using closures. See the Arnold OSL documentation for more details


Namespaces for standins:

Arnold scenes are organized in hierarchies of procedurals, which previously could lead to naming conflicts when identically named nodes existed in different procedurals. Each procedural now has its own naming scope, which automatically solves these conflicts. Nodes inside a standin or procedural can be replaced by other nodes with the overrideNodes parameter. This may be used, for example, to replace shaders in an existing standin. When the parameter is enabled, nodes will replace identically named nodes inside the procedural.

Skydome Light camera visibility:

New camera and transmission parameters control the amount of light contributed to camera and specular transmission rays. It is no longer necessary to create a separate background sky shader for such purposes. A new shader parameter may be used to link closure shaders for additional control in color and transparency. Skydome lights are now preferred over background shaders, as they provide the same lighting functionality with much better sampling.

Color Management / TX:

Arnold now supports color_manager nodes. Maya scenes will be exported with synColor's color manager. This allows output rendered images to be color managed. For input textures, even though it is strongly recommended to rely on preprocessed TX files, non-TX textures will be applied the correct color space per texture lookup at render time (with a corresponding hit in render times). It is also possible now to choose a specific rendering color space.

TX generation is now multi-threaded. Auto-Tx is therefore much more efficient and is in fact instantaneous when textures are up-to-date.

Volume Implicit:

It is now possible to render volumes as implicit surfaces, by changing the volume attribute type to implicit.


Bifrost Liquids are now supported natively. For Aero, Liquid, and Foam, new parameters appear in the Arnold section to control the rendering of the simulation.