attribute-bindings

name	attribute-bindings
description	Replacing persistent ovrtx attribute bindings with reusable ovstage queries for repeated writes or maps. Use when user asks about persistent bindings, repeated writes, efficient animation loops, bind_attribute, or updating transforms every frame with caller-owned tensors.
license	LicenseRef-NvidiaProprietary
version	0.3.0
author	NVIDIA ovrtx
tags	["ovrtx","attributes","bindings"]
tools	["Read","Grep"]

Attribute Bindings

When to Use

Use this skill when the user asks about persistent bindings, repeated writes, efficient animation loops, bind_attribute, or updating transforms every frame with caller-owned data. In new Python code, replace the binding with a reusable ovstage query. Use mapping-attributes when the user specifically needs zero-copy direct access or map/unmap lifetimes.

Inputs

Resolve inputs in this order: existing repository files and referenced snippets, explicit user request, then broader agent context.

• Target API surface: Python, C/C++, or both.
• Prim paths, attribute name, element type, semantic conversion, and whether the attribute is scalar or array-valued.
• Repeated-write cadence, sync/async behavior, caller-owned data location, and whether CUDA stream/event synchronization is needed.
• Whether the user needs reusable query writes, query maps, or one-shot writes.
• Repository source snippets referenced below. Treat these snippets as the API source of truth.

Prerequisites

• Use an ovrtx checkout that contains the referenced examples and docs tests.
• Read the relevant > **Source:** snippet before writing or explaining API usage.
• Use writing-attributes for one-shot or infrequent writes where descriptor creation cost does not matter.
• Use mapping-attributes for zero-copy direct buffer access; this skill can still apply when creating a persistent binding first and then mapping through it repeatedly.

Instructions

1. Identify whether the user needs repeated ovstage writes or maps through a stable query.
2. Read the matching source snippet and copy its create/use/destroy lifecycle rather than inventing equivalent calls.
3. Validate prim list, attribute name, dtype, shape, semantic, and array/scalar rules before proposing or editing code.
4. Keep the ovstage query alive across repeated updates and release it when the hot path ends.
5. Choose mapping-attributes when avoiding the data copy matters more than avoiding descriptor recreation.
6. When changing code, run the narrow docs test or example that owns the snippet whenever practical.

Output Format

• For explanations, cite the relevant API names, source snippets, and caveats.
• For code changes, summarize the files changed, snippets affected, and validation run.

Scripts

This skill has no scripts.

Limitations

• The referenced snippets remain the source of truth; update or add tested snippets before documenting new API usage.

Overview

When writing the same attribute to the same set of prims every frame, create one ovstage query and reuse it for stage.write_attribute() or stage.map_attribute(). Advance the write floor after each ordinal that must become visible to rendering.

Python

Deprecated renderer API: CUDA async write

The following snippet documents CUDA async writes through the deprecated renderer wrapper, including caller-provided stream synchronization:

Source: tests/docs/python/test_attribute_bindings.py snippet doc-write-attribute-async-data-access

Create a reusable query and write

For repeated writes to the same attribute and prims, create a query once:

Source: tests/docs/python/test_attribute_bindings.py snippet doc-bind-attribute-write

Reuse the query for repeated writes

Source: tests/docs/python/test_attribute_bindings.py snippet doc-binding-write-async

Array attribute write through a query

Source: tests/docs/python/test_attribute_bindings.py snippet doc-bind-array-attribute

Write with an explicit semantic

Source: tests/docs/python/test_attribute_bindings.py snippet doc-bind-attribute-write

Use the query for mapping (zero-copy)

Source: tests/docs/python/test_attribute_bindings.py snippet doc-map-bound-attribute

C

Create and use a persistent binding

Source: tests/docs/c/test_attribute_bindings.cpp snippets doc-create-attribute-binding-c, doc-write-bound-attribute-c, doc-destroy-attribute-binding-c

Key Types / Functions

Python	C
stage.query(...) / stage.query_from_path_list(...)	ovrtx_create_attribute_binding(renderer, &desc, &handle)
stage.write_attribute(query, attr, ordinal=..., ...)	ovrtx_write_attribute(renderer, &binding_ref, &buffer, access)
stage.map_attribute(query, attr, ordinal=...)	ovrtx_map_attribute(renderer, &binding_ref, mapping_desc, &out)
query.release()	ovrtx_destroy_attribute_binding(renderer, handle)

Binding flags (C only, set via desc.flags):

• OVRTX_BINDING_FLAG_NONE -- default
• OVRTX_BINDING_FLAG_OPTIMIZE -- optimize internal structures for frequent high-volume writes

Troubleshooting

• Tensor lifetime: Fetched mapping groups are valid only while the ovstage mapping is active. Copy anything that must outlive unmap.
• The canonical transform attribute name is "omni:xform". The legacy name "omni:fabric:localMatrix" (used in examples above) is also accepted. New code should prefer "omni:xform".
• Release reusable ovstage queries explicitly when the hot path is done.
• In C, OVRTX_BINDING_FLAG_OPTIMIZE should be used for the primary hot-path binding. The last binding created with this flag takes priority.

Deprecated Standalone APIs

Persistent ovrtx attribute bindings are deprecated in 0.4 and retained for compatibility. They have no direct ovstage equivalent; reuse an ovstage query handle for repeated read, write, or map operations and release the query when finished.

See docs/core/ovstage_integration.rst, skills/update-0_3-0_4-c/SKILL.md and skills/update-0_3-0_4-python/SKILL.md.

References

• Use the > **Source:** directives in this skill to locate tested snippets before reusing API patterns.
• Keep related skills, docs, and snippets synchronized when changing the workflow.