5.7.1.0

27 March 2024

MAXtoA 5.7.1.0 is a major feature release using Arnold 7.3.1.0.

Installation

Download Arnold for 3ds Max from your Autodesk Account. See Download Arnold for more information about downloading MAXtoA from your Autodesk Account.
Follow these installation instructions.

Enhancements

Automatic Denoising: By default, new scenes automatically have an Intel ® Open Image Denoiser (OIDN) imager. A new option in the Render Settings controls whether a denoiser is automatically added when you create new scene. Existing scenes do not get the default denoiser. (MAXTOA-1745)



without denoising	with imager_denoiser_oidn

Arnold RenderView Updated: Arnold RenderView (ARV) has new snapshot functionality and other polish. (MAXTOA-1727)

Arnold RenderView is now dockable: The Arnold RenderView window (ARV) is now dockable by default, and follows the behavior of other dockable windows. If this is not desired, it can be turned off in the MAXtoA render settings. (MAXTOA-1722)

OCIO environment variable behavior follows 3ds Max color management settings: The color management setup in 3ds Max 2025 has explicit modes to use different OCIO configurations: a default mode, a custom mode, and a mode to follow the OCIO environment variable. MAXtoA passes this mode setting on to the Arnold renderer so that Arnold uses the OCIO environment variable override only when 3ds Max is explicitly set in the OCIO - Environment Variable mode. (MAXTOA-1737)
Ability to use custom imagers: MAXtoA now fully supports the new Imager API, and user-supplied imager plugins (in the Arnold plugin path) are usable from inside MAXtoA. Since Imagers are now considered their own node type in Arnold, they have their own selectable category on export. (MAXTOA-1736)
Support metadata from core: MAXtoA can now use metadata from Arnold core for things like the help text and tooltips for shaders, imagers, and other nodes. However, MAXtoA still ships with its own overrides for some metadata. (MAXTOA-1715)
Update Intel Open Image Denoise (OIDN) to version 2.2.2: The updated denoiser has 10% better performance on CPU, includes some critical bug fixes, and handles high-frequency details better. (ARNOLD-14772)
OptiX denoiser runs on progressive negative AA passes: The OptiX denoiser imager now denoises the low-resolution progressive passes (renders with AA < 0). This should result in higher quality feedback in IPR. (ARNOLD-11487)



Left side shows the previous behavior where denoising was only applied to the AA > 0 passes. Right side is new behavior where all progressive passes are denoised.

MaterialX node definitions: The MaterialX node definitions for Arnold shaders now use the standard surfaceshader and volumeshader types, which make them easier to use in DCCs and mix with standard library shaders. The UI for Arnold MaterialX shaders is also improved with the addition of parameter groups and node categories. (ARNOLD-14717, ARNOLD-14736, ARNOLD-14716)
OCIO environment variable priority: The OCIO environment variable now takes priority over the configuration file set in the Arnold OCIO color manager as well as the builtin OCIO configuration file. A new ignore_environment_variable parameter on the OCIO color manager causes Arnold to ignore the value of the environment variable and restores the previous behavior. The OCIO environment variable is also now taken into account by maketx. (ARNOLD-9012)
Curves in procedural viewport API: Procedurals now return curves nodes in AI_PROC_POLYGONS viewport mode. MAXtoA does not yet support this new API. (ARNOLD-14756)

USD Enhancements

Light linking on custom procedurals: You can now use light linking on custom procedurals such as Yeti in the render delegate. (usd#1730)
Improved tooltips: The tooltips in DCCs for Arnold nodes in USD is much improved. usd#1835
Imager node support: USD support for the new Arnold AI_NODE_IMAGER node type. usd#1870
Export ArnoldOptions as UsdRenderSettings - The Arnold USD exporter covnerts the Arnold options node to UsdRenderSettings, UsdRenderProduct, and UsdRenderVar nodes. usd#1852, usd#1865
Velocities motion blur for points - Points with a velocities attribute now render with motion blur. usd#1868
Better default for transmission ray depth - Set the default transmission depth to 8, so that the default settings work better with glass, and to match default in other Arnold plugins like HtoA and MtoA. usd#1889

API changes

Imager plugin API: A public API is now available for imagers. This adds support for custom and third-party imagers in Arnold. (ARNOLD-10322)

The API is built upon a new AI_NODE_IMAGER node type and is implemented via two main API.

imager_evaluate allows you to modify output pixels of a render.

#define imager_evaluate
static void ImagerEvaluate(AtRenderSession* render_session, AtNode* node, struct AtOutputIterator* iterator, int bucket_xo, int bucket_yo, int bucket_size_x, int bucket_size_y, uint16_t tid)

imager_prepare is an optional API allows you to query the outputs an imager will recieve and prepare any evaluation specific data.

#define imager_prepare
static void ImagerPrepare(AtRenderSession* render_session, AtNode* node, const AtNode* driver, struct AtOutputIterator* iterator, AtImagerSchedule& schedule);

Additionally, there are a couple of helper APIs for the imager_prepare method. These API let you request additional inputs to be rendered for imager evaluation, and to add additional output layers that the user may want to write to the driver.

AI_API bool AiImagerAddInput(AtRenderSession* render_session, const AtNode* imager, const AtNode* driver, int aov_type, AtString aov_name, AtNode* filter);
AI_API bool AiImagerAddOutput(AtRenderSession* render_session, const AtNode* imager, const AtNode* driver, int output_type, AtString output_name);

Tip: See Imager Nodes in the Arnold API Reference. For some example code, see Imagers Nodes in the Arnold Developer Guide. |

Improved builtin metadata: Node and node parameter definitions have been further augmented with metadata that could be useful across DCCs. The metadata that have been added or improved are the following: help, category, ui.groups. Some of these metadata were previously distributed as separate mtd files in each DCC. (ARNOLD-14677, ARNOLD-14678, ARNOLD-14702, ARNOLD-14661)

USD Enhancements

Light linking on custom procedurals: You can now use light linking on custom procedurals such as Yeti in the render delegate. (usd#1730)
Improved tooltips: The tooltips in DCCs for Arnold nodes in USD is much improved. usd#1835
Imager node support: USD support for the new Arnold AI_NODE_IMAGER node type. usd#1870
Export ArnoldOptions as UsdRenderSettings - The Arnold USD exporter covnerts the Arnold options node to UsdRenderSettings, UsdRenderProduct, and UsdRenderVar nodes. usd#1852, usd#1865
Velocities motion blur for points - Points with a velocities attribute now render with motion blur. usd#1868
Better default for transmission ray depth - Set the default transmission depth to 8, so that the default settings work better with glass, and to match default in other Arnold plugins like HtoA and MtoA. usd#1889

Incompatible Changes

OCIO environment variable priority: The OCIO environment variable now takes priority over the file set in the Arnold OCIO color manager. Setting color_manager_ocio.ignore_environment_variable to true restores the previous behavior.

Bug Fixes

MAXTOA-1269 - The width of several UI elements in MAXtoA was unnecessarily large, forcing the 3ds Max command panel to grow
MAXTOA-1688 - Arnold RenderView IPR session should be stopped on color management changes
MAXTOA-1726 - When clicking between multiple Arnold Ramp shaders in SME, the ramps themselves did not update properly
MAXTOA-1742 - In Arnold RenderView, the hot keys sometimes were picked up by 3ds Max. For example, pressing the G key would toggle the grid in 3ds Max, rather than the Green channel in ARV. This has been fixed.
ARNOLD-6309 - System locale should not affect .ass reading or writing
usd#1547 - Fix mesh lights shutoff when there is a light link in the scene.
usd#1859 - Support PointInstancer invisibleIDs for lights
usd#1881 - Support UDIM and relative paths on mtlx image shaders
usd#1884 - Set a proper name to skydome image node in Hydra
usd#1890 - Reduce VtArray memory consumption, specially in the instancer.
usd#1874 - Shader output attributes should be outputs:out to match the Sdr registry
usd#1878 - Make Arnold relative path optional for image shaders
usd#1873 - Ensure materials are written under a scope primitive

System Requirements

Autodesk 3ds Max 2023, 2024, 2025
Windows 10 or later, with the Visual Studio 2019 redistributable.
CPUs need to support the SSE4.1 instruction set.
GPU rendering works requires an NVIDIA GPU with the Maxwell architecture or later. We recommend 537.13 or higher drivers.
Optix™ denoiser requires an NVidia GPU with CUDA™ Compute Capability 5.0 and above.