Runtime Variants#
Capability: Runtime Variants (RV)
Overview#
The Runtime Variants capability defines how a neutral SimReady asset exposes runtime-specific physics behavior through USD variant sets that layer in runtime payloads. The base (neutral) asset stays unchanged when the runtime variants are disabled, and each supported runtime (PhysX, Newton, or MuJoCo) is opted into by selecting its variant, which non-destructively prepends a runtime payload layer.
Summary#
This capability captures the structural contract for runtime physics variants: which variant set an asset root must expose for a given runtime, where that runtime’s payload layer lives on disk, and how the variant is documented in SimReady metadata. Requirements are grouped per runtime so a feature can adopt only the runtimes it targets, mirroring the neutral/PhysX/Newton/MuJoCo feature expansion pattern at the asset-composition level.
Each runtime has three requirements: a variant-set rule, a payload-location rule, and a metadata rule.
Runtime |
Variant set |
Payload |
Metadata |
|---|---|---|---|
PhysX |
RV.001 |
RV.002 |
RV.003 |
Newton |
RV.004 |
RV.005 |
RV.006 |
MuJoCo |
RV.007 |
RV.008 |
RV.009 |
Two cross-runtime rules govern how the variants compose so a selected runtime gets a clean, isolated physics stage:
Rule |
Scope |
|---|---|
RV.010 |
Variant-section purity: |
RV.011 |
Runtime physics isolation: the composed stage for a selected runtime carries only that runtime + neutral data. See the runtime physics isolation matrix. |
For an authoring-oriented overview of PhysX + Newton + MuJoCo on one asset, see Multiple Physics Solvers.