AIF-Entity Profile USD Authoring Guide#

This document describes how to author a USD asset that conforms to the AIF-Entity profile. A single profile covers all of the currently defined NVIDIA AI Factory data center equipment classes. This set will continue to grow and evolve as more equipment types are added; for now it covers the Coolant Distribution Unit (CDU), Computer Room Air Handler (CRAH), Uninterruptible Power Supply (UPS), and Compute Rack (e.g. GB300). Equipment-class differentiation is driven by the aif:core:assetClass property and data-driven validation, not by separate profiles.

Profile definition#

The AIF-Entity profile includes the following feature set (see profiles.toml and the feature dependency graph). Each feature’s requirements and dependencies are defined in the feature specifications.

[AIF-Entity]
"0.1.0" = {features = [
    {"FET000_CORE" = {version = "0.1.0"}},            # Core
    {"FET001_BASE_NEUTRAL" = {version = "1.0.0"}},    # Minimal Placeable Visual
    {"FET200_AIF_NEUTRAL" = {version = "0.1.0"}},     # Core Metadata (capability; interim feature carrier)
    {"FET201_AIF_NEUTRAL" = {version = "0.1.0"}},     # Connection Points (capability; interim feature carrier)
    {"FET202_AIF_NEUTRAL" = {version = "0.1.0"}},     # Thermal Cooling (feature; assetClass-gated to CDU/CRAH)
    {"FET203_AIF_NEUTRAL" = {version = "0.1.0"}},     # Electrical (feature; assetClass-gated)
]}

Features and capabilities#

The AIF-Entity profile composes two kinds of rule set:

  • Features (These rule sets change simulation output): Thermal Cooling (FET202) and Electrical (FET203). These are gated by aif:core:assetClass – thermal applies to CDU and CRAH; electrical applies to CDU, CRAH, and UPS.

  • Capabilities (These rule sets organize and validate, without changing simulation output): AIF Core Metadata and Connection Points.

Note

NOTE: The AIF Core Metadata and Connection Points rules are currently carried inline in the FET200/FET201 feature JSON as an interim measure so they still validate, until SRF supports Profile-to-Capability referencing.

Equipment-class differentiation#

A single profile validates all four equipment classes. The aif:core:assetClass property selects which expected attribute set and connection-point types apply. The validators read assetClass, look up the per-class expectations from configuration, and validate generically.

aif:core:assetClass

Thermal

Electrical

Notes

CDU

Yes

Yes

Facility/technology water loops; full attribute set

CRAH

Yes

Yes

Air-side cooling; liquid connection points

UPS

No

Yes

Power conditioning; no thermal loop

Rack

No

No

Compute rack (e.g. GB300); metadata + connection points

Required USD properties and schemas#

Stage metadata (required)#

  • defaultPrim must be set on every layer.

  • upAxis = "Z" and metersPerUnit = 1 must be set on every stage.

AIF core attributes (required on default prim in *Properties.usda)#

Set aif:core:assetClass to identify the equipment class ("CDU", "CRAH", "UPS", or "Rack"). The full aif:core:* identity, dimension, and documentation attribute set, plus the aif:spec:* attributes defined for the declared equipment class, must be present. See the AIF Core Metadata capability for the authoritative attribute list and the per-class aif:spec:* requirements validated by AM.007 (equipment-class template compliance).

Connection points (required)#

Connection point prims must be authored under a ConnectionPoints Scope prim directly beneath the default prim, following the <vendor>_<type>_<suffix> naming pattern (e.g. nvidia_fws_supply_01) and composed as a separate <AssetName>_ConnectionPoints.usd sublayer. The valid connection-point types depend on the equipment class. See the Connection Points capability for the authoritative type enumeration per class.

Stage composition requirements#

<AssetName>.usd                    <- root stage (sublayer references only)
  <AssetName>_Properties.usda      <- all aif:core:* and aif:spec:* attributes
  <AssetName>_ConnectionPoints.usd <- ConnectionPoints Scope prim and children
  <AssetName>_Geometry.usd         <- mesh geometry (or references to it)

  • The root stage must reference *Properties.usda and *ConnectionPoints.usd as sublayers.

  • All layer paths must be relative.

  • defaultPrim must be set on every layer.

Naming conventions#

Prim naming#

  • Use PascalCase for prim names (e.g., CW375, ConnectionPoints).

  • The default prim name should match the asset model identifier.

File naming#

  • Use the asset model identifier as the base name (e.g., CW375).

  • Sublayer files: <AssetName>_Properties.usda, <AssetName>_ConnectionPoints.usd, <AssetName>_Geometry.usd.

  • Use lowercase for all file extensions.

Connection point naming#

  • Pattern: <vendor>_<type>_<suffix> (e.g., nvidia_fws_supply_01).

  • Vendor prefix: lowercase alphanumeric only.

  • Valid type prefixes depend on the equipment class (see the Connection Points capability).

References#