nvidia-omniverse/ovrtx/render-settings

Render Settings

When to Use

Use this skill when the user asks to change render settings, set max bounces, configure path tracing, change render quality, enable DLSS frame generation, or modify RTX settings on a RenderProduct.

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++, USD, or a combination.
• RenderProduct prim path and the exact omni:rtx:* setting attribute to author or update.
• Desired setting value, USD type, runtime/write timing, and whether reset/warmup behavior matters.
• Existing scene or snippet that already owns related RenderProduct settings.
• 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.
• Confirm the setting belongs on the RenderProduct prim, not on a Camera, RenderVar, or renderer creation option.
• Use writing-attributes when the setting is changed through runtime APIs.

Instructions

1. Identify the RenderProduct path and the exact RTX setting attribute to change.
2. Write settings on the RenderProduct prim, not on the Camera or RenderVar prim.
3. Match the value type to the USD attribute schema and preserve existing authored settings that are unrelated to the request.
4. Apply the writing-attributes skill when setting values through runtime APIs rather than static USD.
5. When changing code, run the render-settings docs test that owns the setting 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

Render settings in ovrtx are written as attributes on the RenderProduct prim. To change a setting, use write_attribute() in Python or ovrtx_write_attribute() in C, targeting the RenderProduct prim path (e.g., /Render/Camera) with the setting's attribute name.

Settings use the omni:rtx: namespace prefix. For example, to set the maximum number of path tracing bounces, write omni:rtx:rtpt:maxBounces as a uint32 attribute.

After changing a render setting, call reset() and run warm-up frames to allow the renderer to converge with the new setting.

Python

Set a render setting on a RenderProduct

Source: tests/docs/python/test_base.py snippet doc-set-render-setting

C

Set a render setting on a RenderProduct

Source: tests/docs/c/test_base.cpp snippet doc-set-render-setting-c

Key Types / Functions

Render Mode Selection

DLSS Frame Generation (dlss:)

DLSS Frame Generation inserts interpolated frames between rendered ones. It is off by default and is enabled per RenderProduct, like any other render setting.

Source: examples/c/vulkan-interop/src/main.cpp snippet enable-dlssg

Enabling frame generation changes the shape of the step results: one step returns output_frame_count == N + 1 output frames instead of 1, ordered with the interpolated frames first and the real rendered frame last. Each frame exposes the same single color render var, and only the last frame carries a meaningful accumulation status. Consumers that assume output_frames[0] is the frame to display or inspect need to be updated before turning this on.

The renderer declines frame generation without failing the step, in which case a step keeps returning a single frame. It requires an Ada or newer GPU that drives the display, the RealTimePathTracing render mode, LdrColor or HdrColor as the only render outputs, and a render resolution of at least 126 pixels per side.

Real-Time Path Tracing Settings (rtpt:)

Sampling and Caching

Ray Bounces and Shading

Firefly Filter

Gaussian Splatting

Path Tracing Settings (pt:)

Path Tracing

Denoising

Sampling and Caching

Firefly Filter

Spectral Rendering

Enable the process-wide spectral material and light backend before creating the first renderer, then enable spectral transport on its PT RenderProducts. Run RGB and spectral comparisons in separate processes; the startup choice cannot change after initialization, including after destroying all renderer instances.

Source (Python startup): examples/python/spectral-rendering/main.py snippet doc-spectral-config-python

Source (C startup): examples/c/spectral-rendering/main.cpp snippet doc-spectral-config-c

Source (USDA): tests/docs/usd/data/spectral_rendering.usda snippet doc-spectral-authoring

Source (USD Python): tests/docs/usd/test_spectral_rendering.py snippet doc-spectral-authoring-python

renderingColorSpace is an attribute of the RenderSettings prim, not the RenderProduct, and has no omni:rtx: prefix.

Non-Uniform Volumes

Multi-GPU

omni:rtx:pt:multigpu:enabled is read from the RenderSettings prim, not the RenderProduct.

Global Volumetric Effects

Anti-Aliasing

View Lighting Mode (Camera Light)

View Lighting Mode replaces all scene lights with a single camera light. By default the camera light is a distant headlight aligned with the view direction; it can be switched to a spot light positioned at the camera. The spot-only settings (radius, cone angle, cone softness) have no effect when the light type is "distant"; the angle setting has no effect when the light type is "spot".

Source: tests/docs/python/test_base.py snippet doc-set-view-lighting