Real-Time Visual Enhancement Shaders/Effects

A lightweight collection of real-time OBS shaders focused on perceptual lighting, luminance shaping, and motion continuity.

These shaders improve perceived visual quality without heavy GPU cost, extra render passes, or offline processing.

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🌍 Overview

This repository contains two core systems:

1. Pseudo 2.5D Relight Effect

A screen-space lighting system that simulates directional light using luminance gradients and pseudo-depth.

2. Motion Persistence Shader

A temporal smoothing system that blends motion over time to reduce perceived frame gaps (useful for 30 FPS content on higher refresh displays).

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💡 Pseudo 2.5D Relight

What it does

Simulates directional lighting on flat images/video by:

• estimating pseudo-depth from luminance
• deriving surface direction from pixel gradients
• applying directional lighting + highlight compression
• remapping luminance using a controllable “graphite response curve”

This creates the illusion of depth, volume, and lighting in 2D content.

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Key Features

• Screen-space pseudo-3D lighting
• Adjustable light position (X/Y)
• Warm/cool key tinting
• Depth-based masking system
• Graphite luminance compression system
• Highlight rolloff (film-style compression)
• Fully real-time (single pass, OBS-safe)

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Recommended Settings (General Use)

Control	Value
Light Softness	1.0
Intensity	0.01 – 0.03
Highlight Start	0.90 – 0.95
Highlight Softening	0.05 – 0.10
Depth Exponent	1.0
Graphite Dark Response	~0.9 – 1.0
Max Luminance	0.995
Min Luminance	0.005

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🌑 Graphite Luminance System (IMPORTANT)

This replaces simple brightness with a controlled compression mapping system.

What it does

Instead of leaving brightness linear:

• Dark values are gently lifted toward Min Lum
• Bright values are gently compressed toward Max Lum
• Midtones are preserved unless modified by shadow weighting

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Mental Model (IMPORTANT)

Think of it like this:

Before:
0.00 → black
1.00 → pure white

After:
0.00 → lifted to MinLum (not pure black)
1.00 → compressed to MaxLum (not pure white)

Then the entire range is redistributed smoothly between them.

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Graphite Dark Response

Controls how strongly shadows are reshaped.

• Lower values → more linear / natural
• Higher values → stronger “ink / graphite lift”
• Uses a shadow-weighted curve so only darker regions are affected more heavily

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🧠 Mid Pivot System (HINGE EXPLAINED)

What “Use Mid Pivot” does

The mid pivot acts like a hinge point in luminance space.

Imagine a folding door:

Dark side  ←───── hinge ─────→ Bright side

Behavior

• Values below Mid → pulled darker or suppressed
• Values above Mid → lifted or brightened
• The pivot itself stays stable

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Simple explanation

• Mid = neutral anchor
• Below mid = “falls into shadow side”
• Above mid = “lifts into highlight side”

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When to use it

• Faces (subtle sculpting)
• UI separation
• Cinematic lighting control
• Depth isolation inside flat scenes

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Recommended Mid Range

Use Case	Value
Natural balance	0.45 – 0.55
Dark-heavy scenes	0.35 – 0.45
Bright UI / overlays	0.55 – 0.70

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💡 Highlight Controls

Prevents bright areas from clipping or flattening.

• Highlight Start → where compression begins
• Highlight Softening → how gradual the rolloff is

Recommended:

• Start: 0.90 – 0.95
• Softening: 0.05 – 0.10

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🎞 Motion Persistence Shader

What it does

Simulates temporal continuity by blending:

• current frame
• previous frame buffer
• motion-direction sampling

This reduces perceived stutter in lower FPS content.

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Key Features

• Motion-based temporal blending
• Directional blur along motion vectors
• Depth-aware persistence control
• Adjustable decay (trail length)
• Perceptual motion weighting

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Recommended Settings

Control	Value
Motion Strength	0.6 – 0.8
Decay Clamp	0.05 – 0.1
Depth Influence	0.0 – 0.3
Frame Time	0 (Raw Mode) or match FPS

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Frame Time Modes

🧭 Calibrated Mode (accurate timing)

FPS	Frame Time
60	0.0167
30	0.0333
24	0.0416

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🌙 Raw Mode (recommended default)

• Frame Time = 0
• Shader derives behavior from runtime sampling

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⚙️ How to Use (OBS)

1. Install OBS Shader Filter plugin (Exeldro or equivalent)
2. Add filter → “Custom Shader”
3. Load .shader / .effect file
4. Apply to:
   • Game capture
   • Display capture
   • Media sources

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🧠 Design Philosophy

These shaders prioritize:

• perceptual improvement over physical accuracy
• real-time performance over simulation fidelity
• minimal sampling cost
• controllable aesthetic response
• OBS pipeline compatibility

The goal is not realism alone — but better perceived clarity, depth, and motion stability in live viewing conditions.

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🔧 Performance Notes

• Single-pass rendering
• No compute shaders
• No external dependencies
• Designed for 30–60 FPS streaming
• Motion shader is heavier due to temporal sampling, but GPU-safe on modern hardware

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🌙 Intended Use Cases

• Live streaming (Twitch / YouTube)
• Game capture enhancement
• Cinematic OBS scenes
• UI depth styling
• Low-FPS → high-refresh perception smoothing

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⚖️ Notes

• Motion persistence requires proper previous-frame buffer support in OBS
• FrameTime accuracy improves motion realism but is optional
• Graphite system is intentionally non-linear for perceptual shaping

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📌 Summary

Two systems working together:

• Relight Shader → spatial perception (light + depth illusion)
• Motion Shader → temporal perception (motion continuity)

Combined, they enhance perceived realism without increasing resolution or render cost.