System - Production

Verbosity

Controls how much detail is show in the 3d app's script/console window that pertains to Redshift rendering from the following options:

• Errors and Warnings (default) - Only show errors and warnings in the 3d app's script/console window, the most critical things for quickly being notified about problems with the scene.
• Detailed Info - Show more detailed information in the 3d app's script/console window.
• Debug - Show all messages, the most detailed information, in the 3d app's script/console window.

Diagnostic Messages

When enabled, it prints even more detailed information to the Redshift log. This is useful for debugging a problematic scene and sharing the results with Redshift developers on the forums as outlined in the Bug Reporting thread.

Log IPR Messages

When enabled, messages are printed to the Redshift Log file during Interactive IPR Rendering. This is enabled by default.

Scene/Geometry Issues

When enabled, it alerts the user via the log file to invalid geometry and other issues found in the scene so the issues can be fixed. 

Only valid geometry is rendered.

Abort on License Failure

When enabled, it aborts rendering when Redshift licensing fails. 

Abort on Missing Resources

When enabled, it aborts rendering when the scene is missing resources like textures and other external references.

Display Behavior

Controls when the Redshift Feedback Display is automatically popped open on screen from the following options:

• Always - Always show the Feedback Display with each render. 
• Errors and Warnings (default) - Only show the Feedback Display when errors and / or warnings are found.
• Errors Only - Only show the Feedback Display when errors are found.
• Never - Never automatically pop up the Feedback Display.

Show Feedback Display 

A button to open the Redshift Feedback Display

Bucket Size

Controls the size of the buckets when rendering from the following options:

• 64 - Renders in 64x64 pixel square buckets.
• 128 (default) - Renders in 128x128 pixel square buckets.
• 256 - Renders in 256x256 pixel square buckets.

Bucket Order

Controls the order in which the buckets are rendered from the following options:

• Spiral (default) - Rendering starts in the center of the frame and spirals out from there to the edges of the frame until the frame is complete.
• Horizontal - Bucket rendering starts at the top from left to right and then moves down left to right until the frame is complete.
• Hilbert - Buckets are rendered using a zig-zag pattern that is designed to pick the next closest bucket to the current one until the frame is complete.

Photometric Units to Meter Scale

Certain features of Redshift such as photographic exposure, physical sun/sky and IES light support require knowledge of the "units to meter" and "candela to square meter" settings. It's important to set these values correctly, otherwise lighting coming from physical light sources might appear too dim or too bright.

If you're working with centimeters (i.e. 1 world unit is 1 centimeter), the units to meter scale should be set to 100. That's because, in this case, 100 world units means 100cm, which means 1 meter. If you're working with meters, then it should be set to 1, because 1 world unit means 1 meter.

cd/m^2 Factor

Photographic exposure, IES lights and the physical sky/sun use the cd/m^2 (candela to square meter) setting. Please make sure to attach a photographic exposure lens shader when using IES lights and physical sun/sky, otherwise your lighting will appear too bright or too dim.

Use Combined Trace Depth from Materials

When enabled, Redshift will use the Combined Trace Depth value set per material  instead of the Combined Trace Depth set in the Globals Render Settings tab.

When disabled - by default, Redshift will use the Combined Trace Depth value set in the Globals tab and ignore the Combined Trace Depth value set at the material level.

Automatically Reduce Samples of Other Effects

Enabled by default, Redshift distributes samples across all secondary ray type effects: brute-force GI, ambient occlusion, area lighting, reflection, refraction, etc.

Redshift attempts to shoot the user-defined number of secondary rays per pixel. It does that by dividing the number of secondary rays by the number of primary rays (unified sampling rays). For more information please see the Unified Sampling page.

 

Volume Grid Emissions

When enabled, it forces Redshift to render with legacy (incorrect) volume grid emission for compatibility with older scenes.

Prior to this fix the following issues may arise:

• Volume emission intensity could be too strong or too weak
• Volume emission result could show a stair-stepped effect
• Volume emission would look ok in-camera but it could be on the weak side as far as its GI contribution was concerned

Cut-Offs Rules

When enabled, it forces Redshift to use the old sampling Cut-Off rules used in Redshift versions prior to version 2.5.

This is provided as a backwards compatibility option to match the look of older scenes.

Non-Inverse-Square Light Decay

When enabled - by default, it forces Redshift to employ a hack exclusively for lights that have linear or no decay ( non-physically correct decay)  in order to make this kind of decay look ‘nicer’ when the surface that is being lit is very close to the light source, but it is not actually correct.

When this hack is disabled, the fall-off can get darker when the distance from the light is less than 1 unit, which is actually mathematically correct.

Bump Sampling Technique

When enabled, it forces Redshift to use an old bump-mapping technique that resulted in less detailed bump-mapping in the distance, particularly if mip-mapping is disabled.

This is provided as a backwards compatibility option to match the look of older scenes.

 

No GI From Volume Scattering

When enabled, it forces Redshift to disable all global illumination contribution from Volume Scattering.

This is provided as a backwards compatibility option to match the look of older scenes.

In the example images below a light is shining primarily on a volume in the center of a room, when No GI from Volume Scattering is enabled this results in very little bounce lighting around the room which looks very unrealistic.

Non Scaling Of Point Clouds

When enabled, it forces Redshift to use an outdated and broken method of scaling for point clouds that use Redshift's native point primitive.

Prior to this fix, if you had a point cloud object and you scaled it, the points would move further apart or closer together but their actual radius wouldn’t change. I.e. the points wouldn’t become smaller or bigger!

This is only provided as a backwards compatibility option to match the look of older scenes.

Refraction Affects Alpha Channel

When enabled, it allows materials with refraction to contribute to the alpha channel. For example, a material with refraction could have an alpha value below 1.0 as long as it isn't refracting something else with an alpha value of 1 like another object or light.

By default, when this option is disabled, alpha channels are completely unaffected by refraction - leaving opacity as the only material property that will affect alpha channel values.

 

Black-Body and Dispersion Technique

When enabled, it forces Redshift to use an old inaccurate and physically incorrect method of rendering black-body (light temperature) and dispersion (abbe) shading that does not work correctly with OCIO rendering.

When disabled - by default, Redshift uses a new and improved rendering method for this kind of shading that features increased realism.

Sub-Surface Scattering GI

When enabled, it forces Redshift to render without sub-surface scattering global illumination.

When disabled - by default, Redshift renders with sub-surface scattering global illumination.

 

Global Volume Anisotropy

When enabled, it forces Redshift to use an outdated method of volume anisotropy for global volume fog that is less stable and breaks down at extreme values.

When disabled - by default, Redshift uses a an improved method of volume anisotropy for the global volume fog that is more stable and holds up better at extreme values.

 

Dispersion Nested Dielectrics Technique

When enabled, it forces Redshift to use an outdated dispersion rendering technique that stops materials with dispersion from being visible through other materials that also have dispersion.

When disabled - by default, materials with dispersion can be seen through other materials with dispersion as you would expect.

Note: Extremely low dispersion values were used for demonstration in the example images below.

Time Behavior

When enabled, Redshift uses an old version of time management.

When disabled - by default, Redshift uses a new version of time management that enables new features like the looping functionality in a Maxon Noise shader.

 

GI Conserve Reflection Energy for Photon Caustics

Conserve Reflection Energy (CRE) is a Global Illumination feature that approximates the look of caustics by simulating very soft bounces of light. While the CRE effect looks nice without caustics, when rendering with caustics the effect is redundant and decreases the contrast provided by actual caustics.

When enabled and rendering with Photon Caustics, Conserve Reflection Energy is enabled resulting in a less accurate render by simulating fake caustics and real caustics at the same time.

When disabled and rendering with Photon Caustics, Conserve Reflection Energy is disabled resulting in a more accurate render where only real caustics are used.

 

Bump Smoothing on Lighting Silhouettes

Enabled by default, it allows Redshift to smooth bump and normal maps on the light silhouettes of objects, where the surface normal and light direction are perpendicular to each other.

This is done to avoid faceting artifacts that can arise in those areas, especially if the object is low-poly. However, this can also produce loss of surface detail that might be necessary in some cases. For this reason, Redshift allows the user to turn off the light silhouette bump smoothing.

Shadow Ray Biasing

Enabled by default, it allows Redshift to use a ray biasing trick in order to avoid self-shadowing artifacts that are most common on low polygon meshes. For more information, please see the Shadow Ray Biasing page.

When a renderer computes shading, it uses the mesh's vertex normals. This way, if the mesh has smooth normals, the renderer can generate smooth lighting even if the mesh is of a low-tessellation. However, this can create the unfortunate situation where a vertex normal might be able to 'see' the light that the polygon cannot!

Enable Secondary Ray Clamping on First Bounce

When enabled, Redshift clamps the first ray that bounces from the surface so that any secondary rays that follow are not as strong.

Sampling Optimizations

Enabled by default, it allows Redshift to further optimize sampling calculations for increased rendering speed with no loss in quality.

 

Shading Normal Adaptation Technique

Controls the method used to render bump and normal maps with the following options:

• Keller (Default) - Uses a method that results in fewer artifacts compared to "None," accentuates light that enters the surface at a parallel angle.

• Skewed Reflection - Uses an alternative method to Keller, captures more light from all around the surface.

• None - Uses the legacy method that is more prone to visual artifacts.

The difference can be subtle between Keller and Skewed Reflection but tends to become more apparent along edges and at an angle to a flat surface as seen below.

Enable

When enabled, it produces a lot of extra information during rendering which is intended to help with diagnosing rendering issues.

Shader Integrity check (Very Slow)

When enabled, it checks the integrity of the shaders during rendering which is intended to help with diagnosing rendering issues.

Auto Memory Management

When enabled, it allows Redshift to analyze the scene and determine how GPU memory should be partitioned automatically between rays, geometry and textures.

Used GPU Memory (%)

Controls how much of a GPU's memory is reserved for Redshift.

By default, Redshift reserves 90% of a GPU's free memory. This means that all other GPU apps and the OS get the remaining 10%. If you are running other GPU-heavy apps during rendering and encountering issues with them, you can reduce that figure to 80 or 70. On the other hand, if you know that no other app will use the GPU, you can increase it to 100%.

GPU Memory Release Timeout (sec)

Controls how long Redshift will hold onto your GPU's memory in seconds.

Redshift reserves a percentage of your GPU's free memory in order to operate but the process of reserving and freeing GPU memory is an expensive operation so Redshift will hold on to GPU memory while there is any rendering activity, including shaderball rendering.

By default if rendering activity stops for 10 seconds, Redshift will release this memory. It does this so that other 3d applications can function without problems. 

NVLink for Volume Grids

Controls how volume grids are handled on a system that is set up for NVLink from the following options:

• Automatic - Redshift will automatically use NVLink when available for volume grids that go out of core.
• Force Enabled - Redshift will use NVLink when available for volume grids.
• Force Disabled - Redshift will not use NVLink for volume grids, even if they go out of core.

NVLink for Geometry

Controls how geometry is handled on a system that is set up for NVLink from the following options:

• Automatic - Redshift will automatically use NVLink when available for geometry that goes out of core.
• Force Enabled - Redshift will use NVLink when available for geometry.
• Force Disabled - Redshift will not use NVLink for geometry, even if it goes out of core.

Irradiance Point Cloud Memory (MB)

Specifies the maximum amount of GPU memory Irradiance Point Cloud computations are allowed to use during the actual "working" process.

The default 128MB should be able to hold several hundred thousand points. This setting should be increased if you encounter a render error during computation of the irradiance point cloud. 

Irradiance Cache Memory (MB)

Specifies the maximum amount of GPU memory Irradiance Cache computations are allowed to use when during the actual "working" process.

The default 128MB should be able to hold several hundred thousand points. This setting should be increased if you encounter a render error during computation of the irradiance cache. 

Texture Cache Free Memory (%)

Specifies the percentage of the leftover GPU memory that can be used for texture caching.

Once reserved memory and rays have been subtracted from free memory, the remaining memory is split between the geometry (polygons) and the texture cache (textures). The "Texture Cache Free Memory" parameter tells the renderer the percentage of free memory that it can use for texturing.

Examples:

1. Say we are using a 2GB videocard and what's left after reserved buffers and rays is 1.7GB. The default 15% for the texture cache means that we can use up to 15% of that 1.7GB, i.e. approx 255MB.
2. Alternatively, say we are using a videocard with 1GB and after reserved buffers and rays we are left with 700MB, the texture cache can be up to 105MB (15% of 700MB).

GPU Texture Cache Max (MB)

Specifies the maximum amount of GPU memory in MB that can be used for texture caching.

CPU Texture Cache Max (MB)

Specifies the maximum amount of CPU memory (system RAM) in MB that can be used for texture caching.

Ray Memory (MB)

Specifies how much GPU memory in MB Redshift will reserve for shooting rays.

By default, If you leave Ray Memory at zero, Redshift will use a default number of MB that depends on the shader configuration.