Combining a Scene with Runtime Prims

Overview

ovrtx only supports one root layer per renderer. Documentation tests often need a base scene (for cameras, lights, geometry, and materials) plus doc-specific prims such as RenderProduct or RenderVar definitions. For that case, use open_usd_from_string() / ovrtx_open_usd_from_string() with an inline root USDA layer that contains a subLayers composition arc to the base scene and authors the extra prims in the same root layer.

This inline sublayer pattern is supported and is the preferred docs-test pattern when the code example needs to demonstrate a single composed stage. Use add_usd_reference* only when the example specifically needs to add or remove referenced content after a root stage is already open.

The Pattern

Build one inline root USDA string that:

1. Uses subLayers = [@/path/to/base_scene.usda@] to bring in the actual scene content.
2. Authors the extra doc-specific prims in the same inline root layer.
3. Is loaded with open_usd_from_string() in Python or ovrtx_open_usd_from_string() in C.

Python source: tests/docs/python/test_sensor_configuration.py snippet doc-add-render-config-layer

C source: tests/docs/c/test_sensor_configuration.cpp snippet doc-add-render-config-layer-c