Multiverse| USD v6 provides you of a complete and artist-friendly workflow to generate USDZ assets for Augmented Reality(AR) directly out of Autodesk® Maya® 2018, 2019, 2020.
You can then use USDZ assets generated by Multiverse with Apple iOS 12, 13 and Apple macOS 10.14“Mojave”, 10.15“Catalina”.
USDZ is a rather new format and in evolutionary phase. Before reading the documentation on how to export assets to USDZ, you should be aware of the native USDZ limitations and characteristics:
“PBR” shading / look development
You can use any number of materials in Maya.
The currently supported material is the StingrayPBS and it can be assigned directly to your geometry, or via the hardwareShader parameter that is present on any Maya materials(e.g. on aiStandardSurface).
Note that StingrayPBS UV offset and UV scale must be left with the default settings.
No refractions
No indirect illumination, though iOS casts soft occlusion automatically and computes some environment illumination.
Geometry
Avoid N-gons, loose vertices and non-manifold topology.
Bad topology is never good!
No volumes nor fog
No displacement
Texturing
One set of PBR textures per material
Only one single UV set, with all UVs packed in within a[0,1] region, no overlapping UVs
No UDIMs
No per-face assignments
Animated transformations: from TRS
Animated affine transformation via animated translations, rotations and scaling of your geometries and transforms.
Animated deformations: from binding of animated joints
Animated deformations from binding of joints/skeletons with geometries.
NOTE — Remember to freeze transformations for all objects before writing the asset.
How to generate USDZ files in Maya with Multiverse
In order to correctly generate USDZ file with shading and texturing you must use the“Stingray PBS” material for assignment. This has also the advantage of providing a correct preview for the look of your asset in the Maya Viewport.
Here’s a step by step tutorial:
Launch Maya(2018, 2019, 2020 on all O/S is supported)
Make sure Load the“ShaderFX” plug-in(this plug-in is part of Maya but is typically not loaded by default):
Load the ShaderFX plugin which provides the StingrayPBS node
Choose which 3D model/asset you want to use, in this case we are using the beautiful Maneki 3D model from J CUBE Inc(the model has a simple hierarchy and a total of 9K polygons):
Assignment of materials — You can either:
Direct assignment StingrayPBS → Shape — Assign one or more StingrayPBS materials to your geometries.
Understand what you can write into USDZ
How to generate USDZ files in Maya with Multiverse