NVIDIA DLSS

NVIDIA DLSS#

EmbodiChain exposes the core NVIDIA DLSS controls through DLSSCfg and passes them to DexSim when the SimulationManager creates its world. The integration applies to the hybrid, fast-rt, and rt renderers. DexSim owns DLSS feature detection, initialization, temporal history, and fallback; constructing a configuration object does not by itself initialize DLSS.

Processing model#

DLSS has two selectable processing modes in the current integration:

  • Ray Reconstruction (RR) denoises ray-traced input and reconstructs the output image.

  • Super Resolution (SR) upscales the image when RR is disabled.

RR and SR are exposed as separate switches, but they are not chained in one frame. RR takes precedence when it is enabled:

RR

SR

Effective path

Enabled

Enabled

RR performs denoising and reconstruction.

Enabled

Disabled

RR runs without a separate SR stage.

Disabled

Enabled

Standalone SR performs the upscale.

Disabled

Disabled

The standard OptiX denoiser/rendering path is used.

EmbodiChain configuration#

The following fields are available under RenderCfg.dlss:

Parameter

Default

Description

dlss_enabled

True

Master switch for DLSS on window and offscreen targets.

offscreen_dlss_enabled

True

Enables DLSS for offscreen camera outputs, including headless simulations.

rayreconstruction_enabled

True

Enables RR denoising and reconstruction.

upscale_enabled

True

Enables standalone SR when RR is disabled.

dlss_quality

2

Quality preset: -1 auto, 0 ultra performance, 1 performance, 2 balanced, 3 quality, 4 ultra quality, or 5 DLAA.

render_width, render_height

0

Optional internal dimensions for FastRT/OfflineRT windows. Zero derives the dimensions from the quality preset.

target_width, target_height

0

Compatibility fields. Set the actual output size on the window or camera instead.

upsample_ratio

None

Optional FastRT/OfflineRT ratio used to derive unset internal dimensions.

exposure_compensation

1.0

Positive exposure multiplier used by the RR bridge.

frame_time_delta_ms

0.0

Render-frame interval in milliseconds. Zero selects DexSim’s automatic measurement; a positive value supplies a fixed interval.

frame_time_delta_ms is deliberately defaulted to 0.0, matching DexSim’s native DLSSConfig default. DexSim measures the elapsed time between rendered frames and uses it in the temporal path. This value describes render cadence, not the physics or control timestep, so it should normally remain 0.0. Specify a positive value only when the application intentionally renders at a known fixed cadence.

EmbodiChain currently mirrors the core DLSS controls only. DexSim’s advanced multi-camera tiled controls are intentionally not duplicated in DLSSCfg; their native defaults remain in effect while the engine manages camera-group rendering.

Quality and resolution#

The quality preset determines the internal render resolution relative to the requested output:

Value

Mode

Approximate internal size

-1

Auto

Balanced-safe scale followed by NGX mode selection

0

Ultra Performance

33% of output

1

Performance

50% of output

2

Balanced

58% of output

3

Quality

67% of output

4

Ultra Quality

77% of output

5

DLAA

100% of output

Set the window output size with SimulationManagerCfg.width and SimulationManagerCfg.height, or set the output resolution in the camera configuration. FastRT/OfflineRT windows may additionally use explicit render_width/render_height values or upsample_ratio. Hybrid and offscreen targets derive their internal resolution from the target output and quality preset.

Examples#

Enable DLSS for offscreen camera observations in a headless simulation:

from embodichain.lab.sim import DLSSCfg, SimulationManagerCfg
from embodichain.lab.sim.cfg import RenderCfg

sim_config = SimulationManagerCfg(
    headless=True,
    render_cfg=RenderCfg(
        renderer="hybrid",
        dlss=DLSSCfg(
            dlss_enabled=True,
            offscreen_dlss_enabled=True,
            dlss_quality=3,
        ),
    ),
)

Use a fixed 60 FPS render interval only when the rendering cadence is known and intentionally fixed:

render_cfg = RenderCfg(
    renderer="hybrid",
    dlss=DLSSCfg(frame_time_delta_ms=16.667),
)

Configure an OfflineRT window with an explicit internal resolution:

sim_config = SimulationManagerCfg(
    width=1920,
    height=1080,
    render_cfg=RenderCfg(
        renderer="rt",
        dlss=DLSSCfg(render_width=1280, render_height=720),
    ),
)

The same settings are available in task JSON/YAML under render_cfg.dlss (decoded into env_cfg.sim_cfg.render_cfg.dlss). Set dlss_enabled: false explicitly when a task must use the standard renderer path.

Availability and fallback#

DLSS requires a Vulkan render device, a compatible NVIDIA GPU and driver, and a DexSim build that includes the NGX runtime libraries. DexSim checks support during renderer startup. If DLSS is unavailable, it falls back to the OptiX denoiser and reports initialization or fallback in the engine log.

For offscreen rendering, each enabled camera group may allocate temporal history and Vulkan exchange resources. Increasing the number or resolution of camera groups therefore increases GPU memory usage. Validate DLSS by rendering an eligible frame and checking the engine log; configuration conversion or world construction alone is not sufficient evidence that DLSS initialized.

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