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
- Identify whether the user needs repeated ovstage writes or maps through a stable query.
- Read the matching source snippet and copy its create/use/destroy lifecycle rather than inventing equivalent calls.
- Validate prim list, attribute name, dtype, shape, semantic, and array/scalar rules before proposing or editing code.
- Keep the ovstage query alive across repeated updates and release it when the hot path ends.
- Choose
mapping-attributes when avoiding the data copy matters more than avoiding descriptor recreation.
- 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 -- defaultOVRTX_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.
- Use the
"omni:xform" attribute name for local transforms.
- 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.
1---2name: attribute-bindings3description: 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.4license: LicenseRef-NvidiaProprietary5---67# Attribute Bindings89## When to Use1011Use 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.1213## Inputs1415Resolve inputs in this order: existing repository files and referenced snippets, explicit user request, then broader agent context.1617- Target API surface: Python, C/C++, or both.18- Prim paths, attribute name, element type, semantic conversion, and whether the attribute is scalar or array-valued.19- Repeated-write cadence, sync/async behavior, caller-owned data location, and whether CUDA stream/event synchronization is needed.20- Whether the user needs reusable query writes, query maps, or one-shot writes.21- Repository source snippets referenced below. Treat these snippets as the API source of truth.2223## Prerequisites2425- Use an ovrtx checkout that contains the referenced examples and docs tests.26- Read the relevant `> **Source:**` snippet before writing or explaining API usage.27- Use `writing-attributes` for one-shot or infrequent writes where descriptor creation cost does not matter.28- 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.2930## Instructions31321. Identify whether the user needs repeated ovstage writes or maps through a stable query.332. Read the matching source snippet and copy its create/use/destroy lifecycle rather than inventing equivalent calls.343. Validate prim list, attribute name, dtype, shape, semantic, and array/scalar rules before proposing or editing code.354. Keep the ovstage query alive across repeated updates and release it when the hot path ends.365. Choose `mapping-attributes` when avoiding the data copy matters more than avoiding descriptor recreation.376. When changing code, run the narrow docs test or example that owns the snippet whenever practical.3839## Output Format4041- For explanations, cite the relevant API names, source snippets, and caveats.42- For code changes, summarize the files changed, snippets affected, and validation run.4344## Scripts4546This skill has no scripts.4748## Limitations4950- The referenced snippets remain the source of truth; update or add tested snippets before documenting new API usage.5152## Overview5354When 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.5556## Python5758### Deprecated renderer API: CUDA async write5960The following snippet documents CUDA async writes through the deprecated renderer wrapper, including caller-provided stream synchronization:6162> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-write-attribute-async-data-access`6364### Create a reusable query and write6566For repeated writes to the same attribute and prims, create a query once:6768> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-bind-attribute-write`6970### Reuse the query for repeated writes7172> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-binding-write-async`7374### Array attribute write through a query7576> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-bind-array-attribute`7778### Write with an explicit semantic7980> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-bind-attribute-write`8182### Use the query for mapping (zero-copy)8384> **Source:** `tests/docs/python/test_attribute_bindings.py` snippet `doc-map-bound-attribute`8586## C8788### Create and use a persistent binding8990> **Source:** `tests/docs/c/test_attribute_bindings.cpp` snippets `doc-create-attribute-binding-c`, `doc-write-bound-attribute-c`, `doc-destroy-attribute-binding-c`9192## Key Types / Functions9394| Python | C |95|--------|---|96| `stage.query(...)` / `stage.query_from_path_list(...)` | `ovrtx_create_attribute_binding(renderer, &desc, &handle)` |97| `stage.write_attribute(query, attr, ordinal=..., ...)` | `ovrtx_write_attribute(renderer, &binding_ref, &buffer, access)` |98| `stage.map_attribute(query, attr, ordinal=...)` | `ovrtx_map_attribute(renderer, &binding_ref, mapping_desc, &out)` |99| `query.release()` | `ovrtx_destroy_attribute_binding(renderer, handle)` |100101Binding flags (C only, set via `desc.flags`):102- `OVRTX_BINDING_FLAG_NONE` -- default103- `OVRTX_BINDING_FLAG_OPTIMIZE` -- optimize internal structures for frequent high-volume writes104105## Troubleshooting106107- **Tensor lifetime:** Fetched mapping groups are valid only while the ovstage mapping is active. Copy anything that must outlive unmap.108- Use the `"omni:xform"` attribute name for local transforms.109- Release reusable ovstage queries explicitly when the hot path is done.110- In C, `OVRTX_BINDING_FLAG_OPTIMIZE` should be used for the primary hot-path binding. The last binding created with this flag takes priority.111112## Deprecated Standalone APIs113114Persistent ovrtx attribute bindings are deprecated in 0.4 and retained for115compatibility. They have no direct ovstage equivalent; reuse an ovstage query handle116for repeated read, write, or map operations and release the query when finished.117118See `docs/core/ovstage_integration.rst`, `skills/update-0_3-0_4-c/SKILL.md` and `skills/update-0_3-0_4-python/SKILL.md`.119120## References121122- Use the `> **Source:**` directives in this skill to locate tested snippets before reusing API patterns.123- Keep related skills, docs, and snippets synchronized when changing the workflow.
nvidia-omniverse