iMMERSE: SMAA

iMMERSE: SMAA is Marty’s iteration of the Subpixel Morphological Anti-Aliasing (SMAA) technique. SMAA is a fast and effective method of anti-aliasing that has become an industry standard since its initial release. It offers better performance compared to other anti-aliasing methods with similar goals, making it an excellent choice for games that only provide solutions like FXAA or lack anti-aliasing options altogether.

SMAA’s Debug

To better understand how SMAA is working, you can use its debug function. These debug options are available at the bottom of the shader arguments.

SMAA Debug View

Arguments

  • Edge Detection Type: Specifies the method used for detecting edges in SMAA. The available options include:
    • Luminance Edge Detection: Detects edges based on brightness differences.
    • Color Edge Detection (Max): Detects edges by identifying the maximum color difference.
    • Color Edge Detection (Weighted): Detects edges using a weighted color difference approach.
    • Depth Edge Detection: Detects edges based on depth information, useful for distinguishing objects in 3D space.

  • Edge Detection Threshold: Determines the sensitivity of edge detection based on the chosen edge detection type. Lower values detect more edges, while higher values detect fewer, focusing on more prominent edges.

  • Depth Edge Detection Threshold: Adjusts the sensitivity of depth-based edge detection. This parameter is only effective if “Predicated Thresholding” is enabled, allowing SMAA to better handle complex 3D scenes.

  • Max Search Steps: Controls the number of steps SMAA takes to effectively smooth edges in the scene. Higher values increase the range of edge smoothing but may slightly impact performance.

  • Max Search Steps Diagonal: Sets the number of steps SMAA uses specifically for detecting and smoothing diagonal edges, which are often more challenging to anti-alias.

  • Corner Rounding: Adjusts the amount of anti-aliasing applied to corners in the scene. This parameter helps in smoothing sharp corners, which can otherwise appear jagged.