RTX Render Settings

You can fine tune the NVIDIA Omniverse RTX™ Renderer renderer’s behavior using a variety of rendering settings, which can help you balance quality and performance depending on your needs.

There are four groups of render settings that affect the NVIDIA Omniverse RTX™ Renderer renderer:

Common

Settings common to all RTX render modes, affecting areas such as scene geometry, materials or lights.

Post Processing

Post Processing effects such as tone mapping, color correction, and motion blur.

Real-Time Ray Tracing

Settings controlling the RTX Real-Time mode.

Path-Tracing

Settings controlling the RTX Path-Traced mode.

Note

Render settings are based on the Viewport Render Mode. This section covers both RTX Realtime and Path Traced Modes.

Render Settings are accessed from the menu bar under Rendering > Render Settings. From the Render Settings panel, you can access the settings for each render mode: one for Real-Time mode and a second one for Path-Traced mode.

RTX Settings

To switch between Real-Time Ray Tracing and and Path-Tracing, select the render mode from the viewport render-mode dropdown.

The Common and Post Processing settings are available for both modes, and show the same settings. In addition, for each mode a middle tab shows the settings unique to that mode.

Common Rendering Settings

RTX Common Settings

Rendering

Setting

Effect

Multi-Threading

Enabling multi-threading improves UI responsiveness

Geometry

RTX Common Settings Geometry

Setting

Effect

Normal & Tangent Space Generation Mode

Select the mode to use to generate Normals and Tangents at triangle mesh vertices. Options are:
AUTO - selects the best mode depending on the data available and data update pattern
CPU - use the CPU. This uses mikktspace to generate tangent basis on the CPU
GPU - use the GPU. This allows deforming meshes to have their normal and tangent
basis updated on the GPU, to avoid the CPU overhead. Tangent basis generation does not use mikktspace in this case
Force GPU - force the use of the GPU to generate normals even when these are valid in the input mesh.

Back Face Culling

Enable back face culling for ‘Single Sided’ primitives.
Note that this only applies to UsdGeom prims that have the custom ‘Single Sided’ flag set.
The ‘Double Sided’ flag is ignored because its default value is false, which is not
not a desirable default in a renderer using ray-tracing to simulate light transport

Wireframe Thickness

Changes the thickness of the wireframe used when a primitive is flagged to be render
in wireframe mode.

Wireframe World Space Thickness

When set, the wireframe thickness value is in world space instead of screen space

Shaded Wireframe

If enabled, the wireframe is shaded with the materials assigned to the primitive
Otherwise the wireframe uses a plain white emissive material

Subdivision Global Refinement Level

Selects a global subdivision level to apply to all primitives with Subdivision Schema set to
Catmull-Clark, Loop, or Bilinear. This over-rides the level selected in those primitives.
Each increment of 1 in this value increases the mesh triangle count by a factor of 4.

Subdivision Feature-adaptive Refinement

Feature-adaptive refinement automatically increases or reduces refinement level based
on geometric features. This reduces the number of polygons used in flat areas for example

Clear Subdivision Refinement Overrides in all Prims

Any assets with the setting Refinement Override enabled will be disabled. This effectively ignores any prims who’s values have been customized in Refinement Level.

Renderer-internal meters per unit

Select the number of units per meter used by the renderer relative to the scale of the scene. Option are Default, Small, Medium and Big
The look of some materials depend on the scene scale, for example subsurface scattering and volumetric shading

Hide geometry that uses opacity (debug)

This allows to quickly hide all objects which have opacity enabled in their material

Materials

RTX Common Settings Materials

Setting

Effect

Disable Material Loading

Skip loading of materials, when opening the file.

Textures: Mipmap Levels to Load

Maximum number of texture mipmap levels to load in any material texture.
Using more mipmap levels results in higher quality texture filtering, but also requires more memory.
This provides a simple control to reduce the amount of GPU memory used for material textures.

Textures: Compression Mipmap Size Threshold (0 to disable)

This controls whether to use compression for textures, depending on their dimensions.
A value of 0 disables the use of texture Block Compression at load time.
When a larger value is used, it defines the maximum mipmap size that we are willing to
to not have in the final texture, in order to allow the texture to be Block Compressed.
The reason for this setting is that texture Block Compression can only be applied when
all the mipmap levels of a texture have dimensions that are multiples of 4 texels.

Textures: on-demand streaming (toggling requires scene reload)

Enabling texture streaming allows to load scenes with many high-resolution textures which do not all fit into GPU memory.
It loads the texture mip levels which are needed for a specific camera view on demand. Texture streaming also improves scene loading performance.

MDL Animation Time Override

Manually override the time value provided to MDL materials

MDL Animation Time Use Wallclock

Enabling this option will use actual elapsed time for animation instead of simulated time

Lighting

RTX Common Settings Lighting

Setting

Effect

Show Area Lights in Primary rays

Makes area lights (Sphere Light, Rect Light, Disk Light, Cylinder Light) visible to the camera.
This has no influence on their visiblity in reflections or refractions (e.g. behind glass)

Shadow Bias

Configurable offset to apply to the shadow ray origin along the surface normal.
Helps reduce self-shadowing artifacts in low polygon geometry.

Use First Distant Light & First Dome Light Only

The renderer will ignore all lights in the scene except for the first distant light
and the first dome light (the ordering determining the ‘first’ light of each type
is not user-controllable)

Dome Light

Hemisphere Sampling

Select how to sample the Dome Light. Options are
Upper & Lower Hemisphere: Samples the entire Dome Light sphere. Use this option when scene objects
should receive light from “below” (below the horizon)
Upper Hemisphere Visible & Sampled, Lower Is Only Visible. Use this option when light is mainly coming
from “above” the horizon (the upper half of the Dome Light sphere)
Use As Env Map: select this option to uniformly sample the Dome Light. This may lead to highly noisy
renders (slow convergence) when the Dome Light contains small, bright spots
When using HDRI sky textures, it is recommended to use one of the first two options, to improve convergence speed of the render

Baking Resolution

Select a ‘power of two’ texture resolution to use as a starting point for the
texture generated when baking the material bound to a Dome Light (if any)

Dome Light Texture Resolution Factor

A factor applied to compute the final texture resolution for a DomeLight texture.
This applies both to Dome Lights with a material bound to them, and those simply using
a Dome Light texture, which might need to be converted to format different from its input format
(e.g.: a cubemap may be converted to a lat/long texture, or viceversa, depending on the renderer’s choice)

Dome Light Material Baking SPP

Number of samples per output texel at which to bake the dome light (i.e. evaluate the Emission function of a
material bound to a DomeLight, if any). For example, baking a procedural cloudy sky to a texture
may require multiple samples to reach a certain image quality.

Simple Fog

RTX Common Settings Simple Fog

Setting

Effect

Simple Fog

Enables the use of a simple and fast exponential fog approximation available in both real-time and path-traced mode
Note this fog is very cheap, only models some absorption and does not model real light scattering

Color

The color or tint of the fog volume

Intensity

The intensity of the fog effect

Height-based Fog - Use +Z Axis

Use positive Z axis for height-based fog calculations. Otherwise use the positive Y axis

Height-based Fog - Plane Height

The starting height (in meters) for height-based fog

Height Density

Density of the height-based fog. Higher values result in thicker fog.

Height Falloff

Rate at which the height-based fog falls off

Distance-based Fog

Enable distance based fog

Distance Density

How dense the fog is at the ‘End Distance’

Start Distance to Camera

Distance from the camera at which the fog begins

End Distance to Camera

Distance from the camera at which the fog achieves maximum density

Flow

RTX Common Settings Flow

Setting

Effect

Flow

Enables simulation and rendering of Flow volumes

Flow in Real-Time Ray Traced Shadows

Enable Flow volumes in ray-traced shadows in real-time mode

Flow in Real-Time Ray Traced Reflections

Enable Flow volumes in ray-traced reflections in real-time mode

Flow in Path-Traced Mode

Enable Flow volumes in Path-Traced mode

Flow in Path-Traced Mode Shadows

Enable Flow volumes in shadows cast by light primitives in Path-Traced mode

Composite with Flow Library renderer

Use Flow’s built-in renderer and composite the results instead of ray tracing
through Flow volumes in the RTX renderer

Use Flow Library Self Shadowing

Enable the casting of shadows by the volume on to itself when using Flow’s built-in
renderer

Max Blocks

Maximum number of Flow volume blocks.
To keep rendering performance high and memory consumption low, this number needs to be kept
as small as possible, while also high enough to contain the entire volume.

Debug View

RTX Common Settings Debug View

Setting

Effect

Render Target

Selects the name of the Debug render target to visualize
The drop-down menu contains a list of all the different render passes.
For full-viewport resolution, use another Anti-Aliasing algorithm than DLSS (in Render Settings > Ray Tracing > Anti-Aliasing)

Output Value Scaling

Scales each per-pixel output value by this factor. Useful to increase or decrease relative differences

Post Processing Settings

Post Processing effects allow real-time manipulation of the rendered image in a variety of ways, including exposure adjustment, tone mapping, color grading, color correction, depth of field, motion blur, bloom and more.

RTX Post Settings

Tone Mapping

RTX Post Settings Tone Mapping

Setting

Effect

Tone Mapping Operator

Select Tone Mapping Method. All operators except Clamp apply the exposure adjustment
based on the parameters below or the results of the auto-exposure feature.
Clamp: leaves the radiance values unchanged, skipping any exposure adjustment
Linear: applies the exposure adjustment but leaves the color values otherwise unchanged
Reinhard: operator based on Erik Reinhard’s tone mapping work
Reinhard (modified): variation of the operator based on Erik Reinhard’s tone mapping work
HejiHableAlu: John Hable’s ALU approximation of Jim Heji’s operator
HableUC2: John Hable’s Uncharted 2 filmic tone map
ACES: operator based on the Academy Color Encoding System
Iray: Reinhard-based operator that matches the operator used by NVIDIA Iray by default

cm^2 Factor

Use this factor to adjust for scene units being different from centimeters

White Point

A color that will be mapped to white on the output

Film ISO

Simulates the effect on exposure of a camera’s ISO setting

Camera Shutter

Simulates the effect on exposure of a camera’s shutter open time

f-Number / f-Stop

Simulates the effect on exposure of a camera’s f-Stop or f-Number aperture

Enable sRGB To Gamma Conversion

Available with Linear/Reinhard/Reinhard(modified)/HejiHableAlu/HableUc2 Tone Mapping

Tonemapping Color Space


Wrap Value

Offset

Modified Reinhard Settings

Effect

Max White Luminance

Maximum HDR luminance value that will map to 1.0 post tonemap

HableUC2 Settings

Effect

White Scale Value

Maximum white value that will map to 1.0 post tonemap

Iray

Effect

Crush Blacks

When the upper part of the dynamic range becomes compressed it naturally loses some
of it’s former contrast, and one often desires to regain some “punch” in the image
by using the Crush Blacks parameter. When 0, the lower intensity range is linear,
but when raised towards 1, a strong “toe” region is added to the transfer curve so
that low intensities get pushed more towards black, but in a gentle fashion.

Burn Highlights

Burn Highlights can be considered the parameter defining how much “over exposure”
is allowed. As it is decreased from 1 towards 0, high intensities will be more and
more “compressed” to lower intensities. When it is 0, the compression curve is
asymptotic, i.e. an infinite input value maps to white output value,
i.e. over-exposure is no longer possible. A good default value is 0.5.

Burn Highlights per Component

Specifies how the Burn Highlights parameter is applied to the different color
components. By default it is applied separately to all channels, which can lead to
saturation loss though. Disabling the parameter applies the Burn Highlights to the
luminance, keeping the output color as close as possible to the input color.

Burn Highlights Max Component

When not using ‘Burn Highlights per Component’, if ‘Burn Highlights Max Component’
is enabled, the maximum value across the R, G and B channels is used in the Burn
Highlights computation. Otherwise the overall luminance is used.

Saturation

Compressing bright color components inherently moves them towards a less saturated
color. Sometimes, very strong compressions can leave the image in an unappealingly
de-saturated state. The saturation parameter allows an artistic control over the
final image saturation. 1.0 is the standard “unmodified” saturation, higher
increases and lower decreases saturation.

Auto Exposure

RTX Post Settings Auto Exposure

Setting

Effect

Auto Exposure

Enable a histogram-based approach to automatic exposure compensation

Histogram Filter

Select a method to filter the histogram. Options are Median and Average

Adaptation Speed

How fast automatic exposure compensation adapts to changes in overall light intensity

White Point Scale

Controls how bright of an image the auto-exposure should aim for.
Lower values result in brighter images, higher values result in darker images. Default value is 10.

Use Exposure Clamping/Min EV/Max EV

Clamps the exposure to a range within a specified minimum and maximum Exposure Value

Color Correction

RTX Post Settings Color Correction

Setting

Effect

Color Correction

Enable color correction

Mode

Choose between ACES (Pre-Tonemap) or Standard (Post-Tonemap) Mode

Output Color Space

Defines the color space used as output of Color Correction
sRGB Linear: scene linear space
AcesCG: ACES CG color space

Saturation

Higher values increase color saturation while lowering desaturates

Contrast

Higher values increase the contrast of darks/lights and colors

Gamma

Gamma value in inverse gamma curve applied before output

Gain

Gain / brightness: a factor applied to the color values

Offset

Color offset: an offset applied to the color values

Color Grading

RTX Post Settings Color Grading

Setting

Effect

Color Grading

Enables / Disables Color Grading effects

Mode

Choose between ACES (Pre-Tonemap) or Standard (Post-Tonemap) Mode

Output Color Space

Defines the color space used as output of Color Grading
sRGB Linear: scene linear space
AcesCG: ACES CG color space

Black Point

Defines the Black Point Value

White Point

Defines the White Point Value

Contrast

Higher values increase the contrast of darks/lights and colors

Lift

Color is multiplied by (Lift - Gain) and later Lift is added back

Gain

Color is multiplied by (Lift - Gain) and later Lift is added back

Multiply

A factor applied to the color values

Offset

Color offset: an offset applied to the color values

Gamma

Gamma value in inverse gamma curve applied before output

XR Alpha and Video Compositing

RTX Post Settings XR Compositing

Setting

Effect

XR Compositing

Enables a pass for use with CloudXR streaming and SDI-video compositing (experimental)

Composite in Linear Space

Applies the XR Compositing pass prior to any other post processing.
Therefore doing any compositing work in Linear space, prior to exposure or tonemapping adjustments.

Composite in Editor

Enables alpha compositing with a backplate texture or SDI video input, as opposed to
to outputing the rendered image with an alpha channel for compositing outside,
either by saving to EXR images or outputing the rendered image to a Cloud XR stream

Default Backplate Texture

The path to a texture to use as a backplate

Default Backplate Color

A constant color to use instead of a backplate texture, if a backplate texture is not set

Enable Lens Distortion

Enables distortion of the rendered image using a set of lens distortion and undistortion
maps provided in the next two settings. Each of these settings is expected to point to
a <UDIM> EXR texture set, containing one image per each of the discrete focal length values
specified in the array of float settings under /rtx/post/lensDistortion/lensFocalLengthArray
(to be exposed here in the future)

Lens Distortion Map

The path to a <UDIM> EXR texture storing the distortion maps for specified focal lengths

Lens Undistortion Map

The path to a <UDIM> EXR texture storing the un-distortion maps for specified focal lengths

Chromatic Aberration

RTX Post Settings Chromatic Aberration

Setting

Effect

Chromatic Aberration

Enable chromatic aberration

Strength Red

The strength of the distortion applied on the Red channel

Strength Green

The strength of the distortion applied on the Green channel

Strength Blue

The strength of the distortion applied on the Blue channel

Algorithm Red

Selects between Radial and Barrel distortion for the Red channel

Algorithm Green

Selects between Radial and Barrel distortion for the Green channel

Algorithm Blue

Selects between Radial and Barrel distortion for the Blue channel

Use Lanczos Sampler

Use a Lanczos sampler when sampling the input image being distorted

Depth of Field

RTX Post Settings DOF

Setting

Effect

Depth of Field Camera Overrides

Overrides settings on the camera and uses Dept-of-Field settings below for ALL cameras

Enable DOF

Enables Depth of Field calculations. If disabled, the camera parameters affecting Depth
of Field are ignored and a pinhole camera model is used instead.

Subject Distance

Objects at this distance from the camera will be in focus

Focal Length (mm)

The focal length of the lens (in mm). The focal length divided by the f-number is the aperture diameter.

f-Number / f-Stop

f-Number or f-Stop (aperture) of the lens. Lower f-stop numbers decrease the distance range from the Subject Distance where objects remain in focus

Anisotropy

Anisotropy of the lens. A value of -0.5 simulates the depth of field of an anamorphic lens

Motion Blur

RTX Post Settings Motion Blur

Setting

Effect

Motion Blur

Enable post-processing motion blur effect

Blur Diameter Fraction

The fraction of the largest screen dimension to use as the maximum motion blur diameter

Number of Samples

Number of samples to use in the filter

Exposure Fraction

Fraction of exposure (shutter open) time to sample

FFT Bloom

RTX Post Settings Bloom

Setting

Effect

FFT Bloom

Enables FFT bloom effect

Scale

Overall intensity of the bloom effect

Cutoff Point

Controls a Cutoff Color that allows fine tuning the radiance range for which Bloom Calculations will have any effect.
Values below the Cutoff Point will not contribute to Bloom calculations

Cutoff Fuzziness

If greater than 0, defines the ‘width’ of a ‘fuzzy cutoff’ region around the cutoff values in each channel.
Instead of a sharp cutoff at the cutoff point, a smooth transition between 0 and the full original values is used

Energy Constrained

Constrains the total light energy generated by bloom.

Physical Settings

Enables a more physically accurate bloom effect using a more physical model

Physical Settings

Effect

Blades

The number of physical blades of a simulated camera diaphragm causing the bloom effect

Aperture Rotation

Rotation of the camera diaphragm

Sensor Diagonal

Diagonal of the simulated sensor

Sensor Aspect Ratio

Aspect ratio of the simulated sensor, results in the bloom effect stretching in one direction

f-Number / f-Stop

Increase/Decrease sharpness of the bloom effect

Focal Length (mm)

Focal length of the lens modeled to simulate the bloom effect

Non-Physical Settings

Effect

Halo Radius

Controls the size of each RGB component of the halo flare effect

Halo Flare Falloff

Controls the falloff of each RGB component of the halo flare effect

Halo Flare Weight

Controls the intensity of the halo flare effect

Aniso Falloff Y/X

Controls the falloff of each RGB component of the halo flare effect in X/Y direction

Aniso Flare Weight

Control the intensity of the anisotropic flare effect

Isotropic Flare Falloff


Isotropic Flare Weight


TV Noise

RTX Post Settings Image FX

Setting

Effect

TV Noise & Film Grain

Enables a TV Noise and Film Grain effects

Enable Scanlines

Emulate a Scanline Distortion typical on old televisions

Scanline Spreading

How wide the Scanline distortion will be

Enable Scroll Bug

Emulates scanline sliding typical on old televisions

Enable Vignetting

Blurred darkening around the screen edges.

Vignetting Size

Controls the size of vignetete region

Vignetting Strength

How heavy/strongly the darkening of the vignette will be

Enable Vignette Flickering

Enable a slight movement/flicker effect on the Vignette

Enable Ghost Flickering

Introduces a blurred flicker to help emulate an old television

Enable Wavy Distortion

Introduces a Random Wave Flicker to emulate an old television

Enable Vertical Lines

Introduces random vertical lines to emulate an old television

Enable Random Splotches

Introduces random splotches typical of old dirty television

Film Grain

Effect

Enable Film Grain

Enables a film grain effect to emulate the graininess in high speed (ISO) film

Grain Amount

The intensity of the film grain effect

Color Amount

The amount of color offset each grain will be allowed to use

Luminance Amount

The amount of offset in luminance each grain will be allowed to use

Grain Size

The size of the film grains

Reshade

RTX Post Settings Reshade

When enabled Reshade Post effects freely available online are enabled as part of the post processing For more information about Reshade visit https://reshade.me/ A collection of Reshade shaders can be downloaded from https://github.com/crosire/reshade-shaders/tree/master

Setting

Effect

Preset path

The full path to a preset.init file containing the Reshade preset to use

Effect Search Dir Path

The path to a directory containing the Reshade shader / effect files that the preset can reference

Texture Search Dir Path

The path to a directory containing the Reshade texture files that the preset can reference

Real-Time Ray Tracing 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 “froxel 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 froxel 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 froxel 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 froxel 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 coeffecient 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 froxel 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 froxel are spatially jittered (randomized). A value of 0 indicates light samples should only be taken from the center of each froxel,
whereas a value of 1 indicates the entire froxel’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 froxel’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 froxel 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 froxel 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.

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 accross 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

Path-Traced Mode Settings

RTX Settings Path-Tracing

Path Trace specific render settings.

Anti-Aliasing

RTX PT Settings Anti-Aliasing

Setting

Effect

Anti-Aliasing Sample Pattern

Sampling pattern used for the purposes of Anti-Aliasing. Select between Box,
Triangle, Gaussian and Uniform

Anti-Aliasing Radius

Radius, in pixels, of the sampling footprint to use when generating samples with
the selected antialiasing sample pattern

Firefly Filtering

RTX PT Settings Firefly Filtering

Setting

Effect

Firefly Filtering

Enables logic to reduce the occurrence of “firefly” artifacts

Max Ray Intensity Glossy

The maximum light intensity (in radiance units) that can be contributed along any
one ray for glossy events (when the firefly filter is enabled)

Max Ray Intensity Diffuse

The maximum light intensity (in radiance units) that can be contributed along any
one ray for diffuse events (when the firefly filter is enabled)

Path-Tracing

RTX PT Settings Path-Tracing

Setting

Effect

Max Bounces

Maximum number of bounces in a path

Max Specular and Transmission Bounces

Maximum number of bounces for specular and transmission events

Max SSS Volume Scattering Bounces

Maximum number of bounces for subsurface scattering within a volume

Max Fog Scattering Bounces

Maximum number of bounces for volume scattering within a fog volume

Max Heterogeneous Volume Scattering Bounces

Maximum number of bounces for heterogeneous volumes

Samples per Pixel per Frame (1 to 32)

Total number of samples used for each rendered pixel in one frame update

Total Samples per Pixel (0 = inf)

Maximum number of samples to accumulate per pixel. When this sample count is reached
the rendering stops and the same image is displayed until a scene or setting change
is detected, causing the rendering process to restart. Set to 0 to remove this limit.

Enable Fractional Cutout Opacity

If enabled, fractional cutout opacity values are treated as a measure of surface
‘presence’, resulting in a translucency effect similar to alpha-blending.
Path-traced mode uses stochastic sampling based on these values to determine whether
a surface hit is valid or should be skipped.

Reset Accumulation on Time Change

If enabled, the Path-Tracer accumulation is restarted every time the MDL animation
time changes. Settings this to false is useful to prevent accumulation reset at every
frame when the ‘animation time’ is changing every frames using wallclock time
(which can be the case when we an animation is not being played, and
wallclock time is used instead of animation time)

Note

While using a higher number of bounces increases accuracy of the final image, it can quickly reduce performance while achieving diminishing returns in terms of image quality.

Sampling & Caching

RTX PT Settings Sampling & Caching

Setting

Effect

Enable Caching

Enables a technique that caches path tracing results for improved performance
at the cost of some correctness.

Enable Many-Light Sampling

Enables a technique that improves the sampling quality (and therefore rendering convergence)
in scenes with many light primitives

Denoising

RTX PT Settings Denoise

Setting

Effect

Denoising

Enable to apply the OptiX Denoiser to the radiance image generated by the renderer.
The OptiX denoiser results in an order of magnitude reduction in rendering times for
a target image quality.

Optix Denoiser Blend Factor

A blend factor indicating how much to blend the denoised image with the original non-denoised image.
A value of 0 shows only the denoised image, while a value of 1.0 shows the image with no denoising applied.

Path-Traced Fog

RTX PT Settings Path-Traced Fog

Setting

Effect

Path-Traced Fog

Enables Path-Traced fog using volume absorption and scattering simulation with a
Henyey-Greenstein phase function
The number of bounces is controlled by Max Fog Scattering Bounces

Density

The density of the fog medium

Height

The maximum height of the fog volume

Falloff

Exponential fall-off of the fog

Color

The color of the fog medium

Asymmetry (g)

The asymmetry of the Henyey-Greenstein phase function (“g” parameter)

Use +Z Axis for Height

If set the volume height is considered along the positive Z. Otherwise use the
positive Y axis

Heterogeneous Volumes

This feature enables path-traced volume rendering of both VDB files (internally converted to NanoVDB, a faster and more compact GPU-friendly volume representation) and procedural MDL based volumes. VDB files can either contain a SDF (signed distance field/level set) or density volume. Currently, the VDB volume material can only be applied to a cube mesh, while procedural volume materials can be applied to any kind of mesh (cube, sphere, torus, etc). Volumes can also overlap with other volumes. The maximum number of overlaps between the volumes is currently limited to four.

How to create a VDB volume object

  • Create a cube mesh

  • In the cube’s Property tab, check isVolume

  • Assign VDBTestMaterial.mdl to the cube

  • In the Property tab of the VDBTestMaterial, assign a VDB file to the volume_density_texture

How to create a procedural volume object

  • Create a cube mesh

  • In the cube’s Property tab, check isVolume

  • Assign either perlinNoise.mdl or worleyNoise.mdl to the cube

RTX PT Settings Path-Traced Heterogenous_Volumes

Setting

Effect

Heterogeneous Volumes

The number of bounces is controlled by Max Heterogeneous Volume Scattering Bounces (under the Path-Tracing section in Path-Traced Mode Settings).
• When set to 1: perform single scattering. Fast, suitable for lowly scaterring volumes like fog.
• When set to a value greater than 1: perform multi-scattering. Slower, suitable for highly scattering volumes like clouds.
Important: Make sure to increase the number of bounces to avoid darkening artifacts.

Transmittance Method

Choose between Biased Ray Marching, Ratio Tracking or Brute-Force Ray Marching. Biased ray marching is the ideal option in all cases.

Max Collision Count

Maximum delta tracking iterations. Increase to more than 32 for highly scattering volumes like clouds.
Important: if set too low, parts of the volume will disappear.

Max Light Collision Count

Maximum ratio tracking iterations. Increase to more than 32 for highly scattering volumes like clouds.
Important: if set too low, parts of the volume will disappear.

Max Density

Upper bound of the density of the volume (called Global Majorant in volume rendering).
Important: if set too low, the volume will appear overly transparent.

Fast VDB

Accelerates volume rendering of VDB files by 3-6x at the same accuracy. This setting does not work with MDL based volumes.

Multi-GPU

RTX PT Settings Multi-GPU

Setting

Effect

Multi-GPU

Enables the use of multiple GPUs in path-traced 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

GPU 0 Weight

The amount of total Path-Tracing work (between 0 and 1) to be performed by the first
GPU in a Multi-GPU configuration. A value of 1 means the first GPU will perform the
same amount of work assigned to any other GPU.

Compress Radiance

Enables lossy compression of per-pixel output radiance values

Compress Albedo

Enables lossy compression of per-pixel output albedo values (needed by OptiX denoiser)

Compress Normals

Enables lossy compression of per-pixel output normal values (needed by OptiX denoiser)

Save Settings

Users can save and load their rendering preferences.

../_images/rtx_saved-settings.png

Save Render Settings

Saving render settings allows you to re-use the render settings later in current or other scene.

  1. In the render tab Click the Hamburger to the far right of Renderer Selection.

  2. Select Save Settings

  3. Choose a Location to Save

  4. Select Save

Load Render Settings

Loading render settings will load a Render Settings file and adjust render settings accordingly.

  1. In the render tab Click the Hamburger to the far right of Renderer Selection.

  2. Select Save Settings

  3. Choose a Previously Saved File

  4. Select Load

Reset Render Settings

Resetting the Render Settings allows users to reset the render settings to default values.

  1. In the render tab Click the Hamburger to the far right of Renderer Selection.

  2. Select Reset Settings

Persistent Settings

Whenever render settings are adjusted in a scene, all render settings are saved with the scene for convenience.