Sampling - Live

Rendering Mode

Controls which engine is used for rendering from the following options.

• Production: Redshift's primary engine for final frame rendering.

• Live: Redshift's fastest interactive engine, offering near real time updates.

Progressive Passes

Controls the maximum number of passes that can be reached. More passes results in higher quality and the less visual noise.

Since Progressive mode can be used in either Interactive Rendering or Final Rendering the behavior of this setting differs depending on the rendering mode and the situation.

• Progressive Passes with Production Interactive and Live Rendering - When Interactive Rendering the Progressive render will only reach the maximum number of Progressive Passes if given the necessary amount of time between scene edits and changes. 
  • For example: If a scene edit takes place before the maximum number of Progressive Passes is reached then a new updated Progressive render will be started and again begin to build back up to the maximum number of Progressive Passes.

• Progressive Passes with Production Final Rendering - In Final Rendering the Progressive render will always reach the maximum number of Progressive passes before moving on to the next frame, no more and no fewer.
  • For example: If your maximum number of Progressive Passes is set to 64 then each frame will be rendered for as long as it takes to reach the 64th pass. Once the 64th pass is reached, Redshift will move onto the next frame and then start the process over for each frame until the entire batch is finished.

Denoising

Enables or disables denoising / upsampling.

• Denoising allows you to render images at a reduced baseline quality (lower sample counts) for increases in render speed.
• Upsampling renders the frame at a lower internal resolution before upscaling it to the final frame resolution.

Engine

Controls the denoising/upsampling engine. Upsampling allows for faster rendering and interactivity at the expense of image quality.

• Native

  • Uses machine learning to upsample renders from a lower resolution to the final target resolution, this allows for faster rendering and interactivity without losing as much detail as traditional upscaling.
  • On Windows DLSS is used with NVidia hardware
  • On Mac MetalFX is used on Apple hardware

• OIDN

  • Uses OIDN denoising with no upscaling
  • Compatible with all hardware

Upsampling Mode

Controls the starting resolution before upsampling to the final target resolution. A lower starting resolution (ultra performance or performance mode) results in faster interactivity and lower quality while a higher starting resolution (balanced or quality mode) results in slower interactivity and higher quality.

• Quality - 44% of target resolution.
• Balanced - 33% of target resolution.
• Performance - 25% of target resolution.
• Ultra Performance - 11% of target resolution.

Quality

Balances speed with quality for OIDN denoising with the following options:

• High - Prioritizes quality over speed, best used for final rendering. Minor differences may appear when comparing results across different hardware architecture.
• Balanced - Balances speed with quality, providing higher quality than Fast and less memory usage than High. Some differences may appear when comparing results across different hardware architecture.
• Fast - Prioritizes speed over quality. Some differences may appear when comparing results across different hardware architecture.
  

Depending on the scene, there may be no difference in image quality between the three options.

Static Frame Denoising

When enabled, OIDN denoising will be used after a certain number of passes to improve quality. This allows for faster interactivity without sacrificing image quality when a frame is able to reach higher progressive passes.

Threshold # Passes

Controls the number of passes that need to be reached before OIDN Static Frame Denoising is used.

Max Subsample Intensity

Limits the maximum value of intensity for each individual sample. The higher the 'Max Subsample Intensity' the harder the renderer has to work to antialias the image.

Usually monitors can show colors ranging from black (0.0, 0.0, 0.0) to white (1.0, 1.0, 1.0). Any color that is brighter than white (like 10.0, for example) will still be rendered as white. But the internal workings of a renderer  do care about these "overbright" colors.

Scenes containing very bright lighting and/or strong emissive materials can be very hard to antialias. The reason has to do with sample filtering: say a pixel was rendered with 64 samples. If most of these samples are mid-gray (0.5, 0.5, 0.5) but there is a single sample that is extremely bright (100.0, 100.0, 100.0), that sample will 'dominate' the final pixel color.