PostFx Masked Screen Blur

Masked Gaussian screen blur effect using a texture mask to selectively blur screen regions. Uses DOF-style Gaussian blur shaders with a blend pass.

Overview

Declarative setup script (no M module). Registers a 4-stage blur pipeline:

1. Downsample - Passthrough at 40% scale
2. Vertical Blur - Gaussian blur in Y direction (DOF shader)
3. Horizontal Blur - Gaussian blur in X direction
4. Masked Blend - Blends blurred result with original using #screenBlurMask

Scene Objects

Pipeline

$backBuffer → Downsample (40%) → Blur Y → Blur X → SimpleBlend($backBuffer, blurred, #screenBlurMask) → $backBuffer

Shader Configuration

-- Vertical blur direction
screenBlurFX_YShader.defines = "BLUR_DIR=float2(0.0,1.0)"

-- Horizontal blur direction
screenBlurFX_XShader.defines = "BLUR_DIR=float2(1.0,0.0)"

Blend Pass Textures

-- The final blend reads 3 textures:
simpleBlendShader:setField("texture", 0, "$backBuffer")      -- Original
simpleBlendShader:setField("texture", 1, "$inTex")           -- Blurred result
simpleBlendShader:setField("texture", 2, "#screenBlurMask")  -- Mask (white=blur)

Notes

• Uses PostEffectMaskedBlur class (not standard PostEffect)
• Renders after OverlayRender bin
• The 40% target scale reduces blur cost while maintaining smooth results
• DOF Gaussian shaders are reused for the blur passes
• The mask texture #screenBlurMask controls per-pixel blur intensity

See Also

• PostFx Glow - Bloom/glow blur pipeline
• PostFx SSAO - Screen-space ambient occlusion with blur