USD for 3ds Max 0.4 Release Notes

USD for Autodesk 3ds Max version 0.4 is a feature release with your installation of 3ds Max 2024. For important legal information about this version, please refer to the following: About USD for 3ds Max.

Important:

3ds Max USD 0.4 and MaxtoA 5.6.1 both use a version of USD that provides important security enhancements. It is recommended that you upgrade to these versions or higher of 3ds Max USD and MaxtoA. 3ds Max USD 0.4 is available for download from your Autodesk account and MaxtoA is available for download from the Arnold downloads page.

Note:

USD for Autodesk 3ds Max is supported by systems capable of running 3ds Max 2022 and higher. USD for Autodesk 3ds Max is a standalone product that must be downloaded and installed separately of 3ds Max. For installation instructions, visit Install USD for 3ds Max.

What's New

Latest Features

The following features are available with USD for 3ds Max 0.4:

Support: Updated the USD version to 22.11 for 3ds Max 2024.
Updated USD Exporter:
- New Skin option (USDSkel support) in the USD Exporter. When enabled, skinned meshes will export as USDSkel instead of animated vertex caches.
- Plug-in Configuration Options in USD Exporter. Updated the material target list in USD exporter UI to only list USD Preview Surface, other targets are expected to be enabled as part of plug-in configurations (ie. targets are available when contexts are registered).
- USD Exporter now exports a basic material even when the material is not understood (Name and diffuse color).
- Added an option in the USD Exporter to allow nested Gprims. This option is off by default. When enabled, it produces "invalid" USD files but maintains the hierarchy of prims, with the potential benefit of improving roundtripping performace by keeping the prim count low.
- Updated USD Exporter default primvar names are now st0, st1, st2, etc. to align more closely with the names used in other applications (such as Maya). This enables ease of material library reuse across applications.
Updated rollouts for a USD Stage Object (see work with USD data in the Command Panel):
- Fixes/Updates to Animation Rollout in USDStageObject.
- USDStageObject now has better support for multiple UVs in the Viewport, for offline USD Stage rendering using the fallback method.
Release of the Max USD SDK that allows 3rd-party developers to extend the USD Exporter. SDK available in a separate download from the Autodesk developer network.

What's Fixed:

Fixed some transparent materials not displaying in the Viewport.
Added warnings to the USD Export log when exporting to USDSkel and there are modifiers above the Skin modifier.
Disabled modifiers changing the geometry in a way incompatible with UsdSkel on export.
Fixed USDStageObject.SelectRootLayerAndPrim() not returning the Payloads option. The Payloads option now returns as a boolean in the third item in the resulting array.
Improved support for opacity in the MaxUsdPreviewSurface material.
Fixed defect causing unexpected evaluation of the stage while manually editing the Stage mask.
Fixed defect where texture paths could be wrong in the USDZ exporter.
Fixed crash when changing a USD Stage's prim's active state via scripting and then changing the display settings of the stage.
Fixed defect where the RenderUSDTimeCode could only be queried at the current frame in the Max timeline.
Fixed crash in USD Exporter when a PrimWriter had changed the USD hierarchy in a way that the exporter did not expect.

Known Issues and Current Limitations

USD Exporter and USD Importer Limitations
Texture graphs are not supported, only direct bitmap inputs are supported in the USD Exporter, Importer and Stage.
Motion Blur data is unsupported.
USD Importer does not import animations.
When importing a USD file containing Normal Map data into 3ds Max 2024, the object's surface may look facetted/ the UV seams become apparent. Workaround: Ensure that gamma correction is enabled. Open the bitmaptexture node in slate, click the file browse button and explicitly set the gamma to 1.0.

USD Blend Shapes Limitations
Morph targets export with USD blendshapes, but skinning information may not properly display in USDView. If you use 3ds Max 2023 or below, this issue presents in USDView. Workaround: Set the Windows Environment variable to: USDSKELIMAGING_FORCE_CPU_COMPUTE=1.
USD cannot resolve the modifier stack like morphers. Any morpher modifier is expected to be below the Skin modifier when they both are present in a 3ds Max node. A warning presents when this hierarchy is incorrect.
USD Skel does not support faceVarying Normals. This extends to other features that use USD Skel (including Morpher).

USD Stage Object Limitations
The USD Stage Object will not display lights, cameras or shapes in the viewport.
Most modifiers will have no effect on a USD Stage Object.
Rendering support for the stage is dependent on each renderer. See the rendering section for more information.
Display of baked bitmaps can cause blurriness of scenes even in high quality mode in the Viewport. Baked bitmaps (ie. with Uberbitmap) are unsupported even in high quality mode in the Viewport.
A 2024 OpenGL Import error is reported relating to the Numpy module. This warning is expected but won't affect the usage of USDView with 3ds Max 2024.
USD Skel does not support faceVarying Normals. This extends to Morpher, as well. This is a USD limitation, and not specific to USD for 3ds Max tools.

MaterialX Limitations
3ds Max 2022: MaterialX materials on a USD Stage reference cannot be displayed in Nitrous (Viewport) nor using Arnold as a renderer.
For USDView bundled with 3ds Max 2022 and 2023: when exporting or viewing an existing .usd file with MaterialX data present, the viewport in USDView will be black and unusable.
Loss of parameters when exporting MaterialX material. In maps, for example: subsurface_scale value is lost.
MaterialX samples have unexpected UV stretching. For example at the equator of a sphere prim. Workaround: Edit the MaterialX file's UVs manually using 'Explode Permanently'. However, in this technique, the material becomes an OSL composite representing the MaterialX file rather than a true MaterialX sample.
Importing USD files when MaterialX is present in the data can result in a failure to import all Materials (like USD Preview Surface).
USDZ format cannot export MaterialX data as part of the USDZ framework. See USDZ specifications.