Sobel No Bleed Blur Shader

It is recommended to place this shader following anti-aliasing shaders in your shader chain. It is recommended to

configure the variables in the shader to your taste. Disable blur if performance is an issue.

The basis for this mod is derived from previously available watercolor shaders, credit to all those who ported and added

functionality to these shaders: Kamikaze, zilav, wazabear, urm.

The previous watercolor shader caused issues with the visuals due to the blur it applied. This shader is configurable such that

blur may be disabled, and if enabled the blur is dampened across edges in the scene (this minimizes blurring causing colors

to bleed across one another in high gradient areas such as NPC faces/eyes, or other fine detail areas). The application of

the Sobel operator is also improved by applying it across RGB color channels separately, and the option of using a larger stencil

size for the operator.

The LQ Blur option is derived from a kawase blur method ported to openMW by Epoch.

Shader tested using the OpenMW dev build v0. 49 and MGEXE v0. 17. 0 + MWSE v2. 1. 0.

------------------------------------------------------------------------------

Configurable Variables

------------------------------------------------------------------------------

Enable Blur:                 (default: ON) Enable/Disable edge-preserving blur effect.

Enable Sobel Filter:    (default: ON) Enable/Disable the Sobel filter that darkens edges.

Exclude Sky:                (default: ON) Exclude sky from Sobel filter (edges of stars in the night sky can look weird).

Edge Color Amount:   (default: 1. 5) Increase/Decrease the intensity at which the Sobel edges are darkened.

Detail:                           (default: 0. 75) Increase/Decrease the intensity at which the pixel color is mixed with the darkened Sobel edges.

Detail Exponent:          (default: 1. 0) A lower exponent picks up fine details more.

5x5 Sobel:                    (default: ON) Enable/Disable a larger stencil Sobel filter for smoother results.

RGB Sobel:                  (default: ON) Enable/Disable application of the Sobel filter on separate color channels. Detects edges better.

Enable HQ Blur:          (default: ON) Enable/Disable computing the edge-preserving blur with true Gaussian weights.

Local Var Threshold   (default: 3. 5) Higher values suppress blurring across texture edges.

Blur Radius:                 (default: 1. 5) Larger values increase the amount of blurring.

LQ Blend Strength:     (default: 0. 8) Blurred image blending fraction with the scene (negative values sharpen the image). Only relevant is Enable HQ Blur if OFF.

Show Sobel Edges:    (default: OFF) When ON, shows only the Sobel filter results.