Omniverse Usd Performance Tuning

Execute recorded targets

Execute the manifest's retained prims, dependencies, mesh paths and tolerances in its output workspace. Process each distinct asset once per pass. An approved operation chain may supply these records directly. Fill missing information without reselecting boundaries. A request to validate before optimizing continues into authorized operations when preconditions pass. Invalid or stale inputs block only dependent work.

Validation scope

Use the concept registry and executor to resolve checks for the requested scope. Register standalone optimizer validators explicitly with usd_optimize.validators.register_all(); importing the module alone does not register them. Use ValidationEngine(init_rules=False) and enable only the resolved checks. Category discovery is evidence of availability, not authorization for a full-category sweep.

The end-to-end workflow runs whole-stage source safety checks before asset authoring and captures the source profile before optimization. Use its recorded results; do not run those phases separately before invoking it. For standalone operations or reconstruction outside that workflow, select every registry concept with role: safety_gate and scope_policy: whole_stage before mutation. Resolve composition and binding failures before dependent work. Asset authoring may supply missing model kinds and organizational Scope types in the output; verify those corrections there. Record pre-existing broken shader connections separately and reject any new connection failure. This registry query avoids a copied checklist. On selected geometry targets, include primvar_unused, primvar_indexability, vertex_weld, topology_zero_area_faces and normals_winding even when the structural assessment has no geometry flags. Check primitive_fit on eligible converted CAD/BIM/MEP targets. A structural scan cannot establish that mesh arrays are already clean.

Use flagged containment pairs for spatial_occluded, excluding transparent enclosures; use flagged routing/overlap pairs for spatial_overlapping and spatial_coinciding. Check nominated duplicate regions with geom_duplicates, adding geom_duplicates_fuzzy for near-match evidence. For simulation, Boolean or printing targets, include topology_manifold, normals_validity and topology_general at the affected targets. Honor recorded skipped targets and explain their unverified coverage. A selected probe can time out or be unavailable; it must not disappear.

Scope costly checks to recorded candidate definitions or containment pairs. Preserve sampled, timed-out, unavailable and not-performed coverage. Check affected authored composition after operations; deep geometric regression checks belong in development tests.

Use validate_concepts(stage_path, concepts, registry=load_registry()) for a cheap selected-rule batch. For costly checks, call run_scope_note with the existing scope-note schema and a bounded subprocess_concept_runner(timeout_seconds=...). Import these functions from the shipped executor; do not reimplement rule resolution. It distinguishes providers with identically named checkers. Every selected concept needs an entry in the scope note's targets; its concepts list alone does not execute checks. Record missing-runtime exceptions as blocked_validation_runtime and timeouts as timeout_recorded. Keep their coverage incomplete even if other targets pass.

Operation parameters

Consult this section while preparing the assessment's operation configuration. The workflow confirms exact cached results before optimization. Apply the conditional execution order to each owned interior. An authorized standalone chain may use deduplicateHierarchies on selected regions and local depth limits, but the successor worker does not accept that operation. The successor worker preserves authored animation samples. optimizeTimeSamples is outside that execution route because this route retains authored samples.

Read only the selected entries in the operation catalog. Use curation, apply_authority, requires_confirmation and parameter_prerequisites; read arguments from the installed version's upstream guide. Prefer canonical operations for matching findings. documentary entries require explicit user intent; specialty operations need supporting findings. Check every operation key against the verified operationsAvailable before execution.

For articulation, physics, metrology, simulation or behavior that depends on variant selections, use the geometric error limit and functional requirements for that use case. The default physical budget alone does not establish functional suitability. Animation and the currently selected variant do not establish a functional accuracy requirement. Preserve their transforms and authored state while applying the visual budget to eligible owned geometry. Physics and contact requirements apply to the retained geometry owner, without propagating through independent child assets to the factory assembly. The successor's supported fitPrimitives configuration is appropriate for eligible piping and large-spatial targets with a notice, provided required identity and appearance survive. encapsulated-product targets need their part identity and fitting intent resolved. Inspect prismatic generic targets on their evidence. The worker enables Sphere, Cone, Cube and Cylinder fitting and preserves nonconstant primvars and subsets. Use USD Optimize's default fitting tolerances; the agent does not tune them or convert a millimeter budget into relative fitting settings. Explicitly requested vertexTolerance and volumeTolerance settings pass through unchanged. vertexTolerance controls relative root-mean-square (RMS) surface error; volumeTolerance controls relative volume error. Neither is a millimeter limit or a maximum surface-deviation guarantee. Exact-geometry requirements exclude fitting; resolve a stricter fitting requirement before enabling it in that scope.

A pipeline inherits each selected operation's requirements. Read prerequisite arrays or the object's fields and elicit_from_user entries. Missing required preflight fields block that operation; optional fields refine its parameters. Batch unresolved questions using the catalog's defaults, conversion and skip option. When no prerequisites block exists, derive parameters from user constraints, scoped evidence or the documented physical budget/upstream default. Ask for a necessary value with no defensible default. Never invent an option ladder. Existing authorization remains effective for the same scope and budget. Weld-only meshCleanup may run as auto within the authorized scope; its catalog base remains intent-gated because topology-repair modes require their own decision. Explain the proposed change, its affected prims and the loss it introduces when a new decision is needed. Offer the catalog's skip option, or a plain instruction to skip that operation. Only present applicable operations with supporting findings.

For small-mesh deletion, set request.remove_small_geometry_mm to the authorized maximum dimension in millimetres (for example, 2 for 2 mm). Omit it to retain small geometry. The worker runs native removeSmallGeometry before mesh cleanup, fitting, reduction and merging, converts the threshold using stage units and the largest occurrence scale, and excludes required interfaces. This threshold is separate from surface-error tolerance. Lossless requests exclude deletion.

The following catalog operations need an authorized standalone chain with its own scope and composition checks; they are outside the successor worker's supported operation set. For removePrims, deletePrims, removeUntypedPrims and deleteHiddenPrims, inspect the exact prim list, variants and runtime visibility. boxClip requires the region and keep-versus-clip choice. diceMeshes, manifoldMeshes, remeshMeshes and shrinkwrap require the proposed grid/voxel settings, topology change and a representative preview. pythonScript requires a user-supplied or reviewed script and authorization to execute it. removeAttributes requires the exact attributes and their downstream consumers. moveMaterials renames every material's prim path; it requires the destination path and the bindings, references and layers that address the current material paths. A sparseMeshes finding alone does not authorize the resulting split or deletion.

Physical geometry budget

The default physical budget for geometry reduction is 0.1 mm. Record any user override. Primitive fitting uses the native relative tolerances described above, independently of this budget. Explicit exact-geometry requirements exclude approximation in their scope. Independently preserve materials, required topology, attributes, authored animation, relationships, units and semantic identity; geometric tolerance does not relax them.

Convert with tolerance_stage_units = mm_tolerance / (metersPerUnit * 1000). Account for the largest occurrence scale in shared definitions' local budgets. Use the budget for applicable native settings across the chain. Report configured limits separately from independently measured deviation; normal execution trusts supported native operations and does not re-prove their geometric algorithms. For decimateMeshes, maxMeanError is a mean-error setting, not a maximum pointwise deviation guarantee. Retain it as the quality budget and set reductionFactor: 0.0 to disable the default 50% keep quota. A triangle target is a ceiling, not permission to disable fidelity limits. Record native results; do not increase error beyond an authorized budget to reach a count. Rate-led reduction belongs to an explicitly requested level-of-detail count specification. Set pinBoundaries: true for shared edges. reductionFactor is the percentage of vertices kept after the operation's internal weld, not a percentage of authored CAD vertices; compare face counts and measured geometry when evaluating reduction.

Interpret primitive-fit analysis from each primitive type's meshCount and nonconstPrimvarMeshCount; top-level composedCount is not the candidate count. Reassess fit candidates after removing UVs proven unused by all consumers. Preserve remaining required primvars and subsets.

Primitive fitting defaults can discard nonconstant primvars and subsets. When they must survive, use ignoreNonConstPrimvars: false and/or ignoreSubsets: false to skip affected meshes; these flags restrict fitting. Normal primvars alone do not require that restriction. Choose settings that preserve the required primvars, subsets and appearance.

Use findCoincidingGeometry and findOverlappingMeshes only on the nominated spatial scopes. findFlatHierarchies identifies prims with large child lists; it does not identify redundant single-child Xform chains and is not a prerequisite for flattenHierarchy. optimizePrimvars can compact eligible primvar storage while retaining interpolation, indexing and required values. Retain material and downstream primvar requirements in its settings.

Editable operation inputs

Use the isolated working layers prepared by asset authoring. Open the authored definition as a stage and select its owned geometry. Never optimize through an instance proxy or edit an inherited persistent definition.

Inspect actual traversal when an operation succeeds without expected work: roots, masks, classes, instances or undefined ancestors can exclude the target. Preserve referenced over holders; promoting one to def can render an additional copy. Convert a class to a concrete definition only in the editable asset that needs it. Count geometry schemas separately: zero meshes does not mean an empty asset.

Conditional execution order

• Probe occlusion with findOccludedMeshes without a deletion decision; delete discovered geometry only within the user's explicit purpose. Authorized deletion precedes work on retained geometry.

• Use generateNormals only when missing or invalid normals require it. Weld eligible vertices with meshCleanup before decimation; preserve UV seams and hard normals. Topology repair such as makeManifold is a separate decision from weld-only cleanup.

• Select geometry_representation from the asset's geometry and workload. For piping and conduit sections, choose analytic_primitives: clean, fit eligible pipes/conduits with native fitPrimitives, reduce remaining meshes, then merge compatible fittings, brackets and supports that remain meshes. Use the same order for other service sections whose geometry supports analytic shapes, such as round ducts. Native fitting determines which meshes qualify under the recorded appearance and accuracy requirements. A static section can remain one atomic asset containing both analytic primitives and merged meshes. Analytic shapes need neither independent placement nor separate child-asset boundaries. Factory visualization alone is not a reason to bypass fitting of pipe or conduit geometry. If a workload requirement excludes this representation, record that requirement in the asset decision's reason. For equipment interiors and fence modules, choose merged_meshes to consolidate static parts: clean and reduce, then merge recorded groups. Their merge inputs are excluded from fitting; other eligible meshes may still fit. Record the choice and reason with the asset decision. Preserve retained child assets, authored animation and required interfaces. Publish the optimized outputs using the category-library workflow.

• Keep merge last among geometry-changing operations. Do not weld or run meshCleanup on merged output; contacting surfaces can be lost. Reassess only remaining unmerged scopes and do not replay fitting or reduction for cleanup findings.

• After merging, run native pruneLeaves, then flattenHierarchy inside eligible static scopes of atomic and package definitions, then prune again. Removing empty siblings first exposes single-child chains to flattening. Flattening removes intermediate Xforms, including static non-identity transforms; pruning removes empty Xforms and Scopes. Keep the asset root, retained child assets, required editable prims, animated interfaces and addressed targets. Static editable Xforms can move to shorter paths while retaining their name and placement; the worker records those paths for publication and interface checks. Animated and externally addressed prims retain their paths. The worker derives scopes and updates geometry paths from native outputs; no per-Xform agent decisions are needed. Record native outcomes and removed prim counts. Static purpose, refinementLevel and refinementEnableOverride on geometry move with their prim; those properties alone do not protect ancestor Xforms. Authored animation and explicit interfaces still do.

• Run computeExtents, remove proven unused data, then clean up the assembly while retaining protected prims. Keep pruneLeaves's preserveUnloadedPayloads: true. Never remove primvars without proving that material/shader consumers do not need them; textured/scanned assets retain required UVs. Check UsdShade connections, primvar readers and MDL consumers before removing a primvar with removeUnusedUVs or direct authoring; uncertain usage means retaining it.

• Apply an explicitly requested palette after merge on editable output layers, through apply_palette.py. Its nearest-color behavior is not permission for a generic appearance change. Include referenced over-holder content and preserve its specifiers.

For deduplicateGeometry on the verified package family, tolerance is absolute in stage units. Use considerDeepTransforms: 0 unless the other setting has been qualified in development tests. Its instanceable-reference default can make later decimation a no-op; optimize definitions before instancing or use a verified non-instancing method.

Interior merge

For native merge, read boundary_path, protected_paths, and the interior operation_scope from the target. Use explicit mesh_paths and output_path; the scoped helper supplies native meshPrimPaths. Different material bindings and face GeomSubset children in the materialBind family can merge: native merge preserves their face assignments through material subsets. Keep other child prims and explicitly addressed subsets outside the merge. The scope helper groups eligible meshes by protected scope. Native merge determines compatibility, handles supported primvar interpolation and indexing, and preserves material assignments. Use the recorded mesh paths and exclusions; native merge may partition incompatible mesh-wide attributes.

Use component_scope.py's check_stage_scope(stage, target) immediately before merging. It returns the native merge configuration only when the selected meshes are authored in the edit layer and the output stays inside the retained Xform or Scope. It checks recorded protected paths, motion, physics and relationship targets. Assessment and execution use the same definition-local internal_paths, including accepted organizational ancestors inside the asset. Internal scope stops at retained child assets; an organizational prim outside the asset cannot exempt its descendants. Within that scope, source kinds, names and descriptive CAD material attributes do not establish protected interfaces. Material bindings are preserved by native merge. Record required semantic boundaries in protected_paths; tools expand accepted internal subtrees without asking for every descendant path. The frontier and report validator share these scope checks. A failed check blocks this merge; report the offending paths instead of silently changing the target. An unscoped merge requires the existing recorded identity_change_authorization or intent_confirmed evidence.

Read the installed mergePoint options before execution. The scoped helper uses Root Prim (mergePoint: 7) with a rootPath relative to the selected meshes' common top-level root. Stage mode can also stop at a composition root, so an absolute name can duplicate that prefix. Keep the absolute destination in operation_scope.output_path; resolve and check the native result against that destination before remapping source paths. Both inputs and output must stay inside the retained boundary and any population mask.

Merge eligible interiors within the retained asset boundary with native spatialMode: 0 (the default). Do not compute an AABB surface-area ratio or impose a coherence cutoff. When a loading, visibility or culling requirement calls for spatially bounded meshes, use native clustering instead: put spatialMode: 1, spatialThreshold and spatialMaxSize in the merge group's operation_scope.spatial_merge settings. Read their units and semantics in the installed merge documentation. Do not invent universal distance or size limits. spatialMode: 2 caps vertex count; spatialMode: 3 merges shared seams and is not a general spatial partition.

For clustered merges, operation_scope.output_path is the containing prim for native output meshes. The worker records all returned paths and removed source paths; it does not infer which input belongs to each cluster. Subsequent assessment, publication and reporting include every output. Retain material assignments, protected paths and placement. Spatial clustering never expands the selected scope.

For optimizeMaterials, set materialsPath in the layer authoring the materials. Assembly overrides cannot remove referenced library data.

Point-instancer conversion when requested

Point-instancer conversion removes individual prim paths and requires explicit authorization and supported scope/remapping handling. Native catalog availability does not establish that the workflow can preserve those interfaces. Retain unsupported content and report the limitation; do not infer emptiness from zero mesh count. organizePrototypes concerns existing scene-graph prototypes, not point-instancer conversion.

Invoke, schedule and persist

Run scripts/successor_workflow.py --manifest MANIFEST --workspace OUTPUT --max-workers N with an assessed successor manifest and a fresh output directory. For a shared library, add --common-library LIBRARY_DIRECTORY; supply its index.json during assessment of each subsequent station and run one publisher at a time. The station consumer is OUTPUT/after.usdc; publication layout is defined in asset authoring. The compute adapter uses the existing native worker and batch runner. Each unique definition has an isolated writer, native execution evidence and output/composition checks. Explicit content prerequisites determine scheduling; shared category membership does not serialize geometry computation. Publication follows asset authoring.

Require evidence for cleanup, primitive fitting, reduction, merging and reuse on each definition. Execute applicable work within the recorded budget; explain unchanged or inapplicable results with inspected evidence. Inspect outputs and composition; unchanged counters alone do not establish completion. The worker measures each written definition by geometry schema, including analytic primitives. A mesh count of zero does not establish an empty target.

Use the compute adapter's resume support only while source, dependencies, runtime, parameters and output fingerprints match. Failed checks invalidate dependent work; independent ready jobs can continue. Retain failed written outputs for inspection.

Export edited layers with Sdf.Layer.Export() to new .usdc files. For compacting an existing output, export to a sibling temporary file, verify it, then replace it atomically. Save() can retain unused crate arrays. Stage.Export() flattens composition; the final consumer must retain the agreed references and occurrence interfaces.