Omniverse Realtime Viewer

Feature patterns

Controllers

• Sample both IWER controllers every animation frame on the controlled-client path; sample native actions through public borrowed handles after OVXR startup.

• Freeze grip/aim pose, profile, trigger, squeeze, thumbstick, and focus.

• Enforce the client 1024-byte wire ceiling and the server decoded-size ceiling.

• Normalize physical components before semantic actions.

• Cancel active actions on blur, visibility loss, tracking loss, stop, or profile replacement.

• Extract composed scene triangles once per stage generation in a disposable USD worker and upload one persistent Warp/CUDA mesh. Cast only fixed preallocated right-grab and left-teleport slots while their mapped controls are active. Refit a moved allowlisted target only at release/cancel; never traverse USD, rebuild a mesh, mint an ordinal, or launch an idle query per frame. Unsupported gprims/instances fail closed.

• Keep reported interaction profile, declared physical hardware, measured grip, measured aim, and profile-scoped ray policy separate. Model/trigger alignment may derive from authored locator geometry; never rewrite poses by eye.

Hands

• Sample XRFrame.getJointPose for WebXR's 25 joints and synthesize only the OpenXR palm, yielding the canonical 26-joint order.

• Use periodic int16 keyframes and keyframe-relative deltas. A lost delta must not corrupt later frames; reacquisition requires a new full keyframe.

• Publish all 52 proxy leaves in one documented scene transaction on the render owner; native source support is conditional on the installed lifecycle capability. Do not treat the camera-update helper as a general hand API. Visual size may differ from measured contact radius, but never feed display scaling into contact logic.

• Position/orientation VALID bits authorize a joint pose. Preserve TRACKED bits as active-versus-inferred quality telemetry; do not discard valid inferred poses and do not read invalid fields.

• Use hand-scale-relative pinch hysteresis; validate open→pinch→hold→open.

• Keep a validation fixture absent until the first pinch creates it. Once a valid grab owns that fixture, retain ownership and follow the pinch midpoint while the pinch remains active; do not require overlap with the fixture's previous-frame position after motion begins.

• Treat the OVPhysX child write/step/read proof separately from contact-pair verification. If the bridge lacks contact reads, label overlap analytic.

Navigation and anchors

• Store absolute translation, floor yaw, scale, and revision.

• Capture the pivot at gesture begin; compute later updates from the begin state so packet loss cannot accumulate drift.

• Route controller locomotion, teleport, desktop movement, and client gestures into one state stream.

• Reset and increment revision on stage change. Focus loss clears latched input.

• Keep source USD and metersPerUnit unchanged.

• Left-stick forward comes from current VIEW forward projected to the floor. Use the live managed anchor for user movement, yaw and scale; preserve the head pivot and source scene roots. See the self-contained navigation contract.

XR UI

• Keep UI out of USD and OVRTX scene geometry.

• Prefer the controlled-client renderer when runtime composition layers are not public. Use stable surfaces/nodes, revisions, ray/UV hit tests, capture, and cancel on focus or tracking loss.

• Correlate actions to server state; reject stale document revisions.

• Controller-pointer features inherit the same measured ray, source lifetime, capture cancellation, and navigation-space tests as scene tools even though client-native UI creates no USD geometry.

Cross-feature acceptance

Use the spatial-input feature validation checklist for every new tracked pose, interaction tool, anchor, or generated visual. A feature-specific happy-path test is not enough: preserve the disabled-feature head-tracking control, transaction ownership, lifecycle cleanup, bounded hot path, consumed-stage proof, and visible-pixel gate.

Mirror

• Probe and exercise /dev/shm from the publisher/consumer execution namespace; do not infer native availability from a sandbox mount. Size the mount for the negotiated frame depth and resolution rather than silently redirecting to /tmp.

• Publish pixel order and exact per-frame foveation metadata atomically when the API permits it.

• When NPP is available, downscale on a private CUDA stream to an independent, aspect-preserving publication bound. Rescale pixel-space foveation metadata with the image and report source, requested bound, actual publication size, backend/fallback, pixel reduction, and unchanged headset resolution.

• Use a long-lived staging buffer and asynchronous synchronization.

• Letterbox to preserve aspect ratio. Bound publication and client draw cadence.

• Preview the cadence gate before acquiring an OVXR readback, then enforce it again under the publisher lock. The first check avoids needless context-lock traffic; the second remains authoritative when desktop and headset products share a stream.

• Treat connection and presentation demand separately. A minimized or hidden WebView can remain connected; report visibility over the control plane and use the idle heartbeat until it becomes visible again.

• Keep newest-frame-wins semantics at every handoff. If sequence ordering is already enforced before publication and RAF only draws newer sequences, one retained full-frame WebView buffer is enough.

• Correlate a published frame without changing OVStream's ABI by assigning a monotonic public VideoFrame.start_timestamp_ns and sending a bounded app-owned sideband keyed by the exact resulting SHM capture timestamp. Carry producer epoch/sequence, the ordinal actually consumed by OVRTX, source product, and live submission state as decimal strings. Copy and release the borrowed native pixels before a short exact-key wait; never join nearest timestamps or substitute the current stage floor for a missing mapping.

• Measure each boundary honestly: producer submit time/bytes, native SHM copy, response-body materialization, and WebGL upload. Do not label sequence gaps as queue depth or time only the callback after an arrayBuffer() transfer.

• Verify the installed ovstream version's buffer-lifetime contract before removing application staging; do not infer a newer contract from one machine while the sample still supports an older wheel.

• A performance proof must use the real SHM source, demonstrate advancing frame hashes or sequences, and measure foreground versus idle publication demand. A responsive-layout capture proves presentation and aspect preservation; it does not by itself prove producer throttling, GPU unwarp, or native resize.

• Capability-check ContextDesc.readback_foveation_unwarp in the installed SDK. When it produces rectilinear captures, omit client PQW inversion; applying it again distorts the preview. Distinguish configured readback domain from an actually received image. Some current warped-submission configurations produce no captures despite requesting unwarp: keep headset settings unchanged, report preview unavailable after sustained misses, label any retained image stale, and clear that diagnosis only after a fresh capture sequence. A working disabled-foveation mirror does not prove warped capture compatibility.