RTX Real-Time Settings

RTX RT Settings Ray Tracing

Ray Tracing specific settings.

Eco Mode

Setting

Effect

Stop Rendering After This Many Frames Without Changes

If nothing is updated in the scene, rendering will be paused after this amount of frames,
and will resume when a new update is triggered. This mode is useful to save power on laptops

Anti-Aliasing

Off Setting

Effect

Algorithm

No Anti-Aliasing
RTX RT Settings DLSS Anti-Aliasing

DLSS Setting

Effect

Algorithm

DLSS: NVIDIA Deep Learning Super Sampling

Execution mode

Select between Performance, Balanced or Quality modes

Sharpness

Higher values produce sharper results

Exposure mode

Choose between Force self evaluated, PostProcess AutoExposure, Fixed

Auto Exposure Multiplier

Factor with which to multiply the selected exposure mode
RTX RT Settings TAA Anti-Aliasing

TAA Setting

Effect

Algorithm

TAA: Temporal Anti-Aliasing

Static Scaling

A scaling factor less than or equal to 1.0. If less than 1, upscaling is used

TAA Samples

Higher sample count increases anti-aliasing quality

TAA history scale

Values less than 1 produce smoother result, but may increase ghosting.
Values greater than 1 can help reduce ghosting. The recommended range is 0 to 3
RTX RT Settings FXAA Anti-Aliasing

FXAA Setting

Effect

Algorithm

FXAA: NVIDIA Fast Approximate Anti-Aliasing (this is a spatial-only AA algorithm)

Subpixel Quality

The amount of aliasing removal at the subpixel level. Higher values make the image softer.

Edge Threshold

The minimum amount of local contrast required to apply FXAA algorithm.

Edge Threshold Min

Pixels darker than this are not processed in order to increase performance.
RTX RT Settings RTXAA Anti-Aliasing

RTXAA Setting

Effect

Algorithm

RTXAA: NVIDIA RTX Anti-Aliasing

Sharpness

Higher values produce sharper results

Exposure mode

Choose between Force self evaluated, PostProcess AutoExposure, Fixed

Auto Exposure Multiplier

Factor with which to multiply the selected exposure mode

Direct Lighting

RTX RT Settings Non-Sampled Direct Lighting

Setting

Effect

Direct Lighting

Enable direct light contributions from light primitives

Enable Shadows

Enable shadows from light primitives (global setting)

Enable Sampled Direct Lighting

Enable a direct lighting mode that scales better to handle many lights.
This mode is recommended to deal with scenes with more than about 10 lights.

Auto-enable Sampled Lighting Above Light Count Threshold

When set, the ‘Sampled Direct Lighting’ mode is automatically enabled when a scene has more
than the number of lights set in the ‘Auto-enable Sampled Lighting: Light Count Threshold’ setting

Auto-enable Sampled Lighting: Light Count Threshold

The threshold number of lights used by the ‘Auto-enable Sampled Lighting Above Light Count Threshold’ setting

Non-Sampled Direct Lighting


Shadow Samples per Pixel

Higher values increase the quality of Direct Light Shadows at the cost of some performance

Lower Resolution Shadows Denoiser

Enable for better performance by reducing the resolution of the per-light shadows denoiser

Dome Lighting

Enable dome light contributions to diffuse BSDFs

Dome Light Samples per Pixel

Higher values result in more accurate dome light sampling

Dome Lighting in Reflections

Enable dome light contributions to diffuse BSDFs in reflections
RTX RT Settings Sampled Direct Lighting

Sampled Direct Lighting


Samples per Pixel

Higher values increase the quality of Direct Light Shadows at the cost of some performance

Clamp Sample Count to Light Count

When enabled, take one sample per pixel per light

Reflections: Light Samples per Pixel

Number of times a light source in reflections is sampled (per pixel)

Reflections: Clamp Sample Count to Light Count

When enabled, take one sample per pixel per light seen in reflections

Max Ray Intensity

Clamps the maximum brightness of a light sample

Reflections: Max Ray Intensity

Clamps the maximum brightness of a light sample in reflections

Firefly Filter

Choose the type of filter (None, Median, RCRS). Clamps overly bright pixels to a maximum value

History Clamping

When enabled, reduces temporal lag

Denoiser Iterations

Number of times the frame is denoised

Enable Extended Diffuse Backscattering

Allow light to pass through thin semi-translucent geometry such as tree leaves

Shadow Ray Offset

Shifts the starting point of shadow rays with diffuse backscattering

Extinction

Higher values means less light passing through surfaces with diffuse backscattering

Reflections

RTX RT Settings Reflections

Setting

Effect

Reflections

Enable reflections

Max Roughness

The maximum roughness of the GGX BSDF beyond which no reflections are computed

Max Reflections Bounces

Number of reflection bounces

Translucency

RTX RT Settings Translucency

Setting

Effect

Translucency

Enables translucency for specular transmissive surfaces such as glass

Max Refraction Bounces

Maximum number of refraction bounces

Secondary Bounce Roughness Cutoff

Control when we trace reflection rays from refraction bounces based on how much the
reflection contribution will be noticed

Enable Fractional Cutout Opacity

Enable fractional values of cutout opacity (between 0 and 1) to be used
to denote ‘presence’ or ‘coverage’ of a surface, resulting in a translucency-like
effect similar to alpha-blending

Enable Depth Correction for DOF

When enabled, depth of field takes translucent objects into account

Global Volumetric Effects

RTX RT Settings Global Volumetrics

The global volumetric effects use a three-dimensional “voxel grid”, a camera aligned frustum divided into several depth slices parallel to the camera plane along the camera direction. These depth slices are themselves subdivided into a number of frustum shaped voxels along the width and height of the slice (the amount of voxels is controlled by the “Pixel Density”).

Settings which are denoted with a * have the most impact on the global volumetrics appearance (other settings can be left at their defaults).

Setting

Effect

Accumulation Frames

Number of frames samples are accumulated over temporally. Higher values reduce noise, but increase the amount of time that lighting updates take.

# Depth Slices

Number of layers in the voxel grid to be allocated, higher values use more memory and reduce performance but allow for more depth based precision in the volume.

Pixel Density

The number of screen pixels each voxel is in width and height. Higher values quickly consume more memory and reduce performance but allow for higher fidelity volumetrics.
A value of 4 can give high quality results at the cost of 4x more memory usage than the default value of 8 (beyond that the memory usage goes up quite fast, also depending on the number of depth slices).

Max Inscattering Distance*

The maximum depth in world units (centimeters) the voxel grid is allocated to. If this is set to 10,000 with 10 depth slices, each slice will span 1,000 units
(assuming a slice distribution exponent of 1). Ideally this should be kept as low as possible without causing artifacts in the scene to make the most of the fixed number of depth slices.

Atmosphere Height*

The height in world units (centimeters) which the volumetric medium ends at. This is useful for providing realistic atmospheres when dealing with infinite light sources, such as distant or dome lights.

Transmittance Color/Transmittance Distance*

These settings combined define the overall attenuation coefficient for the volume. Assuming a perfectly white light, the transmittance color is the color it will be tinted to after traveling a
number of units through the volume as specified by the transmittance distance. The Transmittance Distance controls how far light can travel through fog. Lower values yield thicker fog.

Single Scattering Albedo*

Base color of the fog under uniform white light. This is the ratio of scattered light to attenuated light for an interaction with the volume. Values closer to 1 indicate a highly scattering
medium such as water vapor, while values closer to 0 indicate a highly absorbing medium, such as smoke.

Anisotropy Factor

Degree of asymmetry in light scattering. This is the anisotropy of the volumetric phase function, ranging from -1 to 1. -1 is fully backscattering, 0 is fully isotropic, and 1 is fully forward scattering.

Slice Distribution Exponent

Controls the number (and relative thickness) of the depth slices

Inscatter Blur Sigma

Sigma parameter for the Gaussian filter used to spatially blur the voxel grid. 1 means no blur, whereas higher values blur further.

Inscatter Dithering Scale

The intensity of a noise dithering pattern to be applied on top of the volumetric effect. This is typically used to reduce banding from quantization on smooth gradients.

Spatial Sample Jittering Scale

A scale parameter for how far light samples within a voxel are spatially jittered (randomized). A value of 0 indicates light samples should only be taken from the center of each voxel,
whereas a value of 1 indicates the entire voxel’s volume should be randomly sampled from. Should usually be 1.

Temporal Reprojection Jittering Scale

A scale parameter for how far to offset a temporally reprojected sample, once again based on a voxel’s size. A value of 0 indicates temporal samples should be taken exactly where they are calculated,
whereas a value of 1 allows the sample to be offset within a voxel sized area. This acts somewhat like a temporal blur and helps reduce noise under motion.

Apply Density Noise*

Enables a basic coherent noise texture to modulate the scattering coefficient within the volume, acting somewhat like a density modulation.
Note this will not have an impact on the actual overall attenuation as it always assumes the volume is homogeneous as an optimization. Enabling this option will somewhat reduce performance.

Density Noise World Scale*

A scale parameter to adjust the size of the density noise. Larger values create a more dense noise pattern, whereas smaller values produce a more sparse noise pattern.

Density Noise Animation Speed X/Y/Z

A vector to indicate the speed the noise pattern should shift under animation. Note animation needs to be active to display the noise pattern in motion.

Density Noise Scale Min/Max

A range to map the noise values of each octave of the coherent noise to. Typically these should be 0 and 1 respectively, but to make sparse points in the noise less sparse a higher min can be used,
or a lower max for dense points to be less dense.

Density Noise Octave Count

The number of octaves to use in the coherent noise generation. Higher octave counts reduce performance but give more detailed noise patterns.

Use 32-bit Precision

Allocate the voxel grid with 32-bit per channel color instead of 16-bit per channel color. This doubles memory usage and reduces performance, generally not too useful unless specifically needed.

Subsurface Scattering (Experimental)

Setting

Effect

Max Sample Per Frame

Max samples per frame.

Enable Denoiser

Enables denoising for the subsurface scattering.

Enable Transmission

Enables transmission of light through the medium, but requires additional samples and denoising.

Transmission BSDF Sample Count

Transmission sample count per frame.

Transmission Samples Per BSDF Sample

Transmission samples count per BSDF Sample. Samples per pixel per frame = BSDF Sample Count * Samples Per BSDF Sample.

Transmission Screen Space Fallback Threshold

Transmission threshold for screen-space fallback.

Enable Transmission Rendered in Half-Resolution

Enables rendering transmission in half-resolution to improve performance at the expense of quality.

Enable Transmission Sample Guiding

Enables transmission sample guiding, which may help with complex lighting scenarios.

Enable Transmission Denoiser

Enables transmission denoising.

Caustics

RTX RT Settings Caustics

Setting

Effect

Caustics

Enable simulation of caustics generated by light emitted from area light primitives
for which the ‘Enable Caustics’ flag is set. Note only Sphere, Rect and Disk lights support this

Photon Count Multiplier

Factor that will be multiplied by 1024 to compute the total number of photons to generate from each light.

Photon Max Bounces

Maximum number of bounces to compute for each light/photon path

Position Phi


Normal Phi


Filter Iterations

Number of iterations for the denoiser applied to the results of the caustics tracing pass

Indirect Diffuse Lighting

RTX RT Settings Indirect Diffuse Lighting

Setting

Effect

Ambient Light Color

Color of the global environment lighting

Ambient Light Intensity

Brightness of the global environment lighting

Enable Ambient Occlusion (AO)

Enables the use of Ambient Occlusion, which approximates the occlusion

AO Ray Length

The length of the AO rays traced. Geometry beyond this distance will not result in
AO-based darkening

AO Minimum Samples per Pixel

The lowest number of AO samples (rays) to trace per frame

AO Maximum Samples per Pixel

The highest number of AO samples (rays) to trace per frame

AO Aggressive denoising

Increases AO denoising at the cost of more blurring

Enable Indirect Diffuse GI

Enables Diffused Global Illumination

Samples per Pixel

Higher values result in smoother looking GI.

Max Bounces

More bounces allow more potential GI contribution in occluded areas

Intensity

Controls the intensity of the GI contribution evenly across the occluded area.

Denoiser: Kernel Radius

Controls the spread of the local denoising area. Higher values results in smoother looking GI.

Denoiser: Iteration Count

The number of denoising passes. Higher values results in smoother looking GI.

Denoiser: Max History Length

Controls latency in GI updates. Higher values results in smoother looking GI.

Multi-GPU

RTX RT Settings Multi-GPU

Setting

Effect

Multi-GPU

Enables use of multiple GPUs in real-time mode (when these are available and enabled at startup)
Multi-GPU must be enabled at startup by passing adding –/renderer/multiGpu/enabled=true to the command line
The current multi-GPU algorithm in real-time mode splits the rendering of the image into a
large tile per GPU with a small overlap region between these tiles.

Tile Count

Number of tiles to split the image into. Usually this should match the number of GPUs,
but it can be less.

GPU 0 Post Process only

If set, the first GPU is dedicated to post processing only, and no scene rendering is done on it

Tile Overlap (Pixels)

Width, in pixels, of the overlap region between any two neighboring tiles

Fraction of Overlap Pixels to Blend

Fraction of the Tile Overlap region width for which pixels will be blended between tiles