Extend Ovrtx Interactive Edits

Extend OVRTX interactive edits

When to Use

Use when implementing Blender depsgraph extraction, typed USD value conversion, live runtime submission, durable write routing, topology fallback, user diagnostics, and tests.

Boundary

Work in the distributed source checkout and use documented runtime interfaces. Prove a missing runtime capability with the escalation probe before declaring an add-on-only implementation impossible.

Preserve the architecture

Route every edit through this pipeline:

Blender depsgraph signal → InteractiveEdit → EditPlan → InteractiveEditWorkflow → RuntimeScheduler or durable USD write → OvrtxSessionUpdatePort.

Do not call the native client from a Blender callback, UI operator, conversion policy, or depsgraph builder. Do not mutate Blender data from the render thread. Blender RNA reads and writes stay on Blender's main thread; runtime calls stay on the serialized viewport session-owner thread. Queue work through the scheduler and use the existing main-thread handoff in engine.py for results.

Code map

• addon/ovrtx_blender_example/blender_interactive_edit_builders.py: extend build_interactive_edits_from_depsgraph and add a narrowly named builder beside object_transform_edit, material_value_edits_from_resolver, light_value_edits_from_prim, world_value_edits_from_prim, or uv_value_edits_from_resolver. Resolve authored prim identity and attach provenance; never infer a target from display names alone.
• addon/ovrtx_blender_example/value_edit_conversion.py: add or register a ValueEditConversionPolicy in default_value_edit_conversion_policies. Put domain-specific mapping in a focused *_value_conversion.py module. Return typed UsdAttributeValue records and one normalized classification: supported, unsupported, non_rendering, or topology.
• addon/ovrtx_blender_example/interactive_edit_planner.py: extend InteractiveEditPlanner.plan and _value_update_kind only when the new family needs a distinct routing rule. Keep value, topology, authority, and persistence separate in InteractiveEdit, EditPlanImpact, and EditPlan.
• addon/ovrtx_blender_example/write_target_resolution.py: use resolve_write_target for durable opinions. Fail closed on anonymous, session-only, ambiguous, mismatched, or topology-owning layer stacks.
• addon/ovrtx_blender_example/interactive_edit_workflow.py: preserve InteractiveEditWorkflow.preview_edit as the single choice point between update, composition replacement, durable write, and unsupported outcomes. Extend _plan_diagnostics or _topology_fallback_diagnostics when the new route has observable state.
• addon/ovrtx_blender_example/runtime_scheduler.py: queue accepted EditIntent values in RuntimeScheduler.submit_edit; apply them during tick_viewport. Keep view-authoritative updates in ViewUpdateStream and simulation-authoritative initial conditions in SimUpdateStream.
• addon/ovrtx_blender_example/ovrtx_value_updates.py: use OvrtxTransformValue, OvrtxAttributeValue, and OvrtxSessionUpdatePort. Add a new typed value and protocol method only when neither transform nor attribute semantics can represent the operation accurately.
• addon/ovrtx_blender_example/topology_edit_fallback.py: add a stable reason to topology_reasons_for_edit and preserve canonical coalescing and topology_rekey_diagnostics when an edit changes graph shape, prim type, relationships, membership, or authored object topology.
• addon/ovrtx_blender_example/engine.py: keep _live_interactive_edit_depsgraph_handler, submit_depsgraph_interactive_edits_to_active_viewports, register_interactive_edit_bridge, and the persistent file-load lifecycle as the integration boundary. Extend submit_interactive_edit only if the existing generic path cannot carry the result. Surface state through interactive_edit_bridge_diagnostics and viewport diagnostics rather than ad-hoc logging.

Instructions

1. Define the exact Blender source field, authored USD target, USD type, data authority, and whether the change is a value or topology edit.
2. Build one InteractiveEdit per independently writable target. Include blender_property_path, exact usd_prim_path, usd_property_name, typed value metadata, and verified identity. Deduplicate repeated depsgraph signals.
3. Convert Blender values without reading global context. Reject linked, ambiguous, unsupported, or unproven values explicitly; do not silently approximate them.
4. Plan live preview separately from persistence. A live update may remain preview-only; a durable write requires a verified layer target. Never turn a missing write target into permission to modify exported source USD.
5. Submit value edits to the scheduler. Preserve edit wake-up, batching, refinement reset, failure propagation, and session identity. Ensure the native call executes only inside the session-owner render loop.
6. Route topology edits to scene-generation replacement or a verified selected write. Emit a stable topology reason and confirm composition identity changes once; never retry a rejected value update as an untyped topology mutation.
7. Add change-only user reporting and structured diagnostics containing source field, target identity, classification, route, status, reason, typed update counts, and topology re-key state. Do not report success before runtime acknowledgement.

Required tests

Extend these existing suites:

• tests/test_blender_interactive_edit_builders.py: Blender source extraction, evaluated/original identity, exact prim mapping, deduplication, selection changes, and fail-closed cases.
• tests/test_value_edit_conversion.py plus a focused test_<domain>_value_conversion.py: units, typing, boundary values, linked inputs, unsupported values, and topology classification.
• tests/test_interactive_edit_planner.py: value/topology, authority, persistence, missing identity, and unsupported routing.
• tests/test_interactive_edit_workflow.py: scheduler update, write target, composition fallback, rejection, and diagnostics.
• tests/test_runtime_scheduler.py and tests/test_latest_view_render_loop.py: batching, edit wake, owner-thread application, ordering relative to simulation, refinement reset, and failures.
• tests/test_write_target_resolution.py and tests/test_topology_edit_fallback.py: layer ownership, ambiguous stacks, stable reasons, coalescing, and one-time re-key.
• tests/test_interactive_edit_bridge_persistence.py: registration and file-load survival when the handler path changes.

Add tests/test_<feature>_interactive_edits.py for end-to-end behavior. Use fake Blender IDs and a fake typed update port to prove:

1. one supported drag produces the expected typed target and one queued update;
2. repeated callback noise coalesces without duplicate native writes;
3. a topology change replaces composition instead of entering the value lane;
4. unsupported or unresolved targets fail closed with actionable diagnostics;
5. runtime rejection is visible and is never recorded as applied; and
6. no runtime method runs on the Blender callback thread.

Run the focused tests first, then the complete documented test suite. Include one small generic scene with a mesh, material, light, and camera for Blender-level acceptance; do not depend on project-specific assets.

Runtime capability gate

Probe the documented runtime interface with the smallest typed update against one known prim in a temporary scene. Record client/runtime versions, request type, target, response, and diagnostics. Report a runtime capability gap only if the interface cannot express the required operation, rejects a documented supported typed operation, or cannot acknowledge application sufficiently to avoid false success. Missing extraction, conversion, scheduling, fallback, UI, or diagnostics remains add-on work.

Handoff

Return a focused add-on commit, the tests above, generic acceptance evidence, and an explicit addon-only or runtime-capability-gap conclusion.