This is a table comparing some of the features (mostly import/export functionality) of AL_USDMaya and Pixar's USDMaya plugin (roughly up to date at 15/10/2018). Thanks to Christopher Moore from Blue Sky Studios for making the first version of this
| Feature Type | Feature Description | AL_USD | PxrUSD | Notes |
|---|---|---|---|---|
| Exporting | ||||
| Animated Visibility | yes | yes | ||
| Camera | yes | yes | ||
| Filtering / Compressing | ||||
| Duplicate Instances | yes | yes | see AL_USDMaya docs | |
| Merging Transforms | yes | yes | see AL_USDMaya docs | |
| Time Samples | yes | needs investigation | pxr seems to have no compression flags | |
| UVs | yes | needs investigation | pxr seems to have no compression flags | |
| Frame Samples / Sub-Frame Export | yes | yes | see AL_USDMaya docs | |
| Instancing | yes | yes | ||
| Lights | no | yes | Pixar only supports RfM Lights. AL todo: Include Reference Translator for Maya Lights | |
| Mesh | ||||
| Topology and Point Positions | yes | yes | ||
| Varying Topology | no | yes | ||
| Indexed UVs | yes | yes | ||
| Color Sets (by default RGBA and faceVarying) | yes | yes | AL_USD requires colorSet to be called displayColor ( displayOpacity is also supported ). See AL_USDMaya docs. pxrUSD has the same displayColor set requirement, however it handled the missing 'flood data' elegantly. multiple colorSets have not been tested yet* | |
| Subdivision Edge and Vertex Creases | yes | yes | ||
| Dynamic Attributes | yes | yes | ||
| Metadata / extra attrs | yes | yes | ||
| NurbsSurface | no | yes | ||
| NurbsCurve | yes | yes | Note: Not currently renderable in Hydra | |
| BasisCurve | no | no | Note: Renderable in Hydra | |
| Particles | no | yes | ||
| Shaders | no | yes | PxrUsd only supports RfM Shaders | |
| Skin/Joints | no | yes | PxrUsd has basic USDSkel support | |
| Transforms | yes | yes | ||
| Importing | ||||
| Lights | no | yes | PxrUsd only supports RfM Lights | |
| proxyShape | yes | yes | Both have this implemented in similar ways ( at least from USD -> Hydra -> Viewport ) | |
| Supported Animation | yes | yes | through time1 connection | |
| Load Part of Stage | yes | yes | yes, each plug-in has it's own way of importing 'fast' (ie: proxyShape), then diving down into transforms to interact with / update the usd stage (visible in the viewport ) | |
| Load / Switch Variants | yes | yes | AL_USD supports this through listening to variant switches in the USD Stage. PxrUsd has a variantKey on the proxyShape, but that does not seem to work. However the pxrUsdReferenceAssembly nodes are sub-classes of kAssembly's and do offer the representation switching | |
| Shaders | no | yes | PxrUsd only supports RfM Shaders | |
| Selecting / Editing | ||||
| Constraint Based Workflows | yes | limited | AL_USD has bi-directional constraint support, including access to constrain to individual elements of the USD Stage. PxrUSD has limitations due to the Assembly node and not having 'connect to prim' capability (out-of-the-box, might be possible through scripting and such ) | |
| Interface with Native USD | no* | no* | not natively, but through custom commands / plugins ( pxrUsdReferenceAssembly or AL_usdmaya_Transforms or a proxyShape node to each USD Stage ) | |
| Layer Management | yes | no | (not out-of-thebox) AL_USD serializes 'live layer data' so when artist re-opens maya session it opens the usd stage, then your local edits. Once task is complete, layer can be saved out and merged back to the usd stage/file ). PxrUSD seems to require full import / export from usd -> maya nodes, which can impact Maya performance | |
| Partial Stage Selection | yes | yes | ||
| Variant Switching to Rigs | yes | no | AL_USD has a schema for MayaReferences to allow to switch out to rig representations. PxrUSD, while it has slightly better UI to switch model/shading variants (mainly due to being a sub-class of an assembly node), does not have built-in support for switching to a rig variant | |
| VP2 Selection from Stage to Outliner | yes | under investigation | AL_USD has extra selection management going on, and hooks into it's ProxyShapeImportTransforms command. PxrUSD selection ( back to native dag nodes of some form) might not be possible this is being investigated | |
| VP2 Selection of Stage | yes | no/ip | see AL_USDMaya PR |