Extend Ovrtx Semantic Aovs

Extend OVRTX semantic AOVs

When to Use

Use when adding semantic or instance AOV support.

Boundary

Implement stable authoring, product selection, parsing, and presentation in a feature branch of the distributed source checkout. Treat renderer IDs as runtime outputs, not persistent scene identity, and use documented typed readback interfaces.

Code map

• Add semantic_identity.py to inventory evaluated Blender instances, choose stable owners, and produce deterministic class/instance records. Keep this policy separate from renderer-generated numeric IDs.
• Use addon/ovrtx_blender_example/scene_generation.py and the existing geometry/material prim builders to attach semantic records to the same generated prim identities. If semantic opinions are overlays, contribute them through ovrtx_scene_composition.py rather than editing exported source USD.
• addon/ovrtx_blender_example/properties.py and ui.py: expose product selection and identity diagnostics.
• addon/ovrtx_blender_example/render_requests.py: replace a single color-only render_var assumption with normalized requested product descriptors while preserving the existing LdrColor/HdrColor path.
• addon/ovrtx_blender_example/ovrtx_scene_composition.py: author each RenderVar's exact sourceName and orderedVars membership; include product identity in composition/session digests.
• addon/ovrtx_blender_example/ovrtx_runtime_client.py: the current render_result branches accept only LdrColor/HdrColor. Add generic typed selection/decoding beside _render_var_paths; return a new typed AOV result carrying bytes/array, shape, dtype, product path, frame/time, and status.
• Add semantic_aov.py for active-count parsing, ID-map reconciliation, palettes, tight boxes, and derived overlays. Do not put semantic parsing in the native binding adapter.
• addon/ovrtx_blender_example/ovrtx_session_controller.py and viewport handoff code: preserve product identity and never feed integer/record buffers into the RGBA upload path.

Instructions

1. Define stable class and instance ownership across Blender objects, linked data, collections, evaluated instances, USD composition, and flattening.
2. Author typed semantic schemas or supported primvars deterministically and retain an object/prim/label map. Never derive persistent IDs from traversal order or display colors.
3. Expose supported native products such as StableIdSegmentation, SemanticSegmentation, SemanticIdMap, and SemanticBoundingBox2DTight. Record product path, type, shape, dtype, orientation, frame, and camera.
4. Parse raw buffers losslessly, including active-count versus capacity rules. Keep raw integer maps separate from palettes, boxes, labels, and overlays.
5. Test identity propagation, request composition, buffer parsing, and stale frame/camera rejection. Validate a tiny occluded fixture, then a representative multi-object scene at first/middle/last frames.

Required tests

Add tests/test_semantic_identity.py, test_semantic_aov.py, and test_semantic_aov_runtime.py. Extend test_ovrtx_runtime_client.py, test_render_requests.py, test_generated_presentation_defs.py, test_ovrtx_session.py, and test_viewport_handoff.py. Fixtures must cover two classes, two instances of one class, one occluder, padded tight-box capacity, an ID map, unsupported products, stale frames, and lossless integer IDs.

Client/server escalation gate

Use a direct-client fixture with known typed semantics and RenderVars. Escalate only if a documented native product is unavailable, its typed buffer or ID map cannot be retrieved through the official API, or the worker returns incorrect data on the minimal fixture. Missing Blender identity policy, USD authoring, product UI, parsing, or overlays is add-on work.

Handoff

Return the changed files, semantic fixture result, unit/runtime tests, raw product identity, and any add-on/runtime boundary finding. Add previews or a provenance bundle only when requested.