SimReady 3D Art Asset Creation¶
Building 3D art assets for Omniverse and the SimReady standard involves not only being able to create a 3D asset that is photoreal in its visual appearance, but also ensuring that it is set up with proper metadata so that it is immediately useful for anyone who wants to use that content within the Omniverse simulation platform.
The principles of good 3D modeling, UV layout and material creation all need to be adhered to in order to create a successful SimReady art asset. Most of these requirements are standard, common sense practices that a 3D artist should already follow to produce great looking results in the most efficient way possible. For new users, here’s a quick overview of the various things to consider when building a new 3D art asset for SimReady.
Modeling Best Practices¶
There are a small number of basic 3D modeling practices all 3D artists should stick to when building SimReady 3D art assets. These should not be ignored as they affect everything else an artist does beyond this point and can impact whether a model can be considered SimReady. At a high level, ensure you consider the following:
All 3D art assets need to be built to real-world scale
Orientation for an exported 3D model should always be Z-up and it should always be placed at the origin
Required unit scale for export is always set to meters
The 3D art asset must face Front in the “front” viewport of the chosen 3D app
Create models with optimal geometry for curvature without wasting polygons
Name all objects cleanly so they are easily identifiable (no Box01 or pSphere27)
Pivot points must be placed and aligned so the art asset “sits” properly with respect to the ground plane
Any custom created physics collision meshes should avoid convex hulls and can contain multiple component meshes
Each of these requirements will be covered in more detail in the next sections within the documentation.
UV Layout Best Practices¶
When you begin to think about how to unwrap a 3D art asset for texturing and material application, there are some fundamental considerations to make in regard to SimReady. Before cutting up the 3D art asset into UV islands, put some thought into the following requirements:
Ensure all UVs are non-overlapping
Use only UV Channel 1 when generating UVs for a 3D art asset
The target Texel density for your UVs should roughly be 512 pixels per meter (higher density is okay for complex patterns)
UVs should live within 0-1 UV space
Before packing UVs, consider the material being assigned and align the UV orientation to make materials easier to apply based on the texturing pattern
If a model has originated as a CAD/CAM part or assembly, it won’t likely have clean UVs and the user should export that model as an STL file and create UVs in another package (e.g. Rizom, UV Layout, etc.) to make sure they adhere to the SimReady spec points above
Each of these requirements will be covered in more detail in the next sections within the documentation.
Materials Best Practices¶
Building materials for SimReady 3D art assets follows many existing common-sense practices in use today, and further tunes their creation for simulation specific end-uses. Remember that you’re trying to match the real-world aspects of a material, so be sure to gather visual reference materials to assist as needed. It doesn’t matter which 3D application or package an artist chooses to create the materials, but please make sure that the guidelines below are followed:
PBR Metal - Rough workflow is required for all 3D art assets (albedo / roughness / metallic / normal maps are required)
Individual PBR texture maps should be provided at a maximum resolution of 4K or 8K pixels
When conforming to Omniverse, artists should use OmniPBR and OmniGlass MDLs as the baseline for material creation
Limit one MDL material per object for SimReady 3D art assets
Strictly follow the SimReady material naming conventions to ensure your materials can be properly linked to RTX-sensor physical materials.
Each of these requirements will be covered in more detail in the next sections within the documentation.