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.
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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.
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ST is Default UV Set |
If enabled, ST is considered to be the default UV set name.
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Wireframe Thickness |
Changes the thickness of the wireframe used when a primitive is flagged to be rendered in wireframe mode.
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Wireframe World Space Thickness |
When set, the wireframe thickness value is in world space instead of screen space.
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Shaded Wireframe |
If enabled, the wireframe is shaded with the materials assigned to the primitive. Otherwise the wireframe uses a plain white emissive material.
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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.
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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.
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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.
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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.
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Hide geometry that uses opacity (debug) |
This allows to quickly hide all objects which have opacity enabled in their material.
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Enable Instance Selection |
Enables the picking of instances.
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Materials¶
Setting |
Effect |
|---|---|
Disable Material Loading |
Skip loading of materials, when opening the file.
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Texture Max Resolution |
Textures larger than this will be downsampled.
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Texture Compression Size Threshold |
Textures smaller than this size won’t be compressed. 0 disables compression.
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Texture Streaming (toggling requires scene reload) |
Enables texture streaming which allows to load textures at a resolution which meets the view’s needs. This reduces memory usage and load times.
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Texture Streaming Memory Budget (fraction of GPU memory) |
Limits memory budget used for texture streaming.
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Texture Streaming Budget Per Request (in MB) |
Maximum budget per streaming request. 0 makes it unlimited. High or unlimited could lead to stalling during streaming.
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Normal Map Mip-Map Generation (toggling requires scene reload) |
Enables mip-map generation for normal maps to reduce memory usage at the expense of quality.
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MDL Animation Time Override |
Manually override the time value provided to MDL materials
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MDL Animation Time Use Wallclock |
Enabling this option will use actual elapsed time for animation instead of simulated time
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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 visibility in reflections or refractions (e.g. behind glass).
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Shadow Bias |
Configurable offset to apply to the shadow ray origin along the surface normal. Helps reduce self-shadowing artifacts in low polygon geometry.
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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).
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Dome Light |
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|---|---|
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.
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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).
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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 vice versa, depending on the renderer’s choice).
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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.
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Global Volumetric Effects¶
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”).
Setting |
Effect |
|---|---|
Fog 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.
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Fog Height Falloff |
Exponential decay of the fog above the Fog Height.
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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.
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Density Multiplier |
Scales the density of the fog.
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Transmittaned Measurement Distance |
The Transmittance Distance controls how far light can travel through fog. Lower values yield thicker fog.
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Transmittance Colour |
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 medium such as water vapor, while values closer to 0 indicate a highly absorbing medium, such as smoke.
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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.
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Anisotropy Factor (g) |
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.
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Density Noise |
Effect |
|---|---|
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.
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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.
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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.
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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.
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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.
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Misc |
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.
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# 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.
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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).
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Slice Distribution Exponent |
Controls the number (and relative thickness) of the depth slices.
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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.
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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.
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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.
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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.
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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.
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Rayleight |
Effect |
|---|---|
Enable Rayleigh Atmosphere |
Enables an additional medium of Rayleigh-scattering particles to simulate a physically-based sky.
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Rayleight Atmosphere Scale |
Scales the size of the Rayleigh sky.
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Skip Background |
When a domelight is used determine the sky color, the Rayleight Atmosphere will only apply to the foreground while the background sky color is left unaffected.
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Simple Fog¶
Setting |
Effect |
|---|---|
Simple Fog |
Enables the use of a simple and fast exponential fog approximation. Note that this fog is very cheap and only models some absorption, and no light scattering.
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Color |
The color or tint of the fog volume.
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Intensity |
The intensity of the fog effect.
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Height-based Fog - Use +Z Axis |
Use positive Z axis for height-based fog calculations. Otherwise use the positive Y axis.
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Height-based Fog - Plane Height |
The starting height (in meters) for height-based fog.
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Height Density |
Density of the height-based fog. Higher values result in thicker fog.
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Height Falloff |
Rate at which the height-based fog falls off.
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Distance Density |
How dense the fog is at the End Distance.
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Start Distance to Camera |
Distance from the camera at which the fog begins.
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End Distance to Camera |
Distance from the camera at which the fog achieves maximum density.
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Flow¶
Setting |
Effect |
|---|---|
Flow |
Enables simulation and rendering of Flow volumes.
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Flow in Real-Time Ray Traced Shadows |
Enable Flow volumes in ray-traced shadows in real-time mode.
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Flow in Real-Time Ray Traced Reflections |
Enable Flow volumes in ray-traced reflections in real-time mode.
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Flow in Real-Time Ray Traced Translucency |
Enable Flow volumes in ray-traced translucency in real-time mode.
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Flow in Path-Traced Mode |
Enable Flow volumes in Path-Traced mode.
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Flow in Path-Traced Mode Shadows |
Enable Flow volumes in shadows cast by light primitives in Path-Traced mode.
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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.
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Use Flow Library Self Shadowing |
Enable the casting of shadows by the volume on to itself when using Flow’s built-in renderer.
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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.
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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).
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Output Value Scaling |
Scales each per-pixel output value by this factor. Useful to increase or decrease relative differences.
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