CRT Monochrome Shaderpack

"End of Line."

CRT Monochrome Shaderpack is a lightweight GLSL shader pack for Minecraft Java Edition (Iris/OptiFine) that replicates the high-contrast, phosphor-display aesthetic of early 80s computing.

It replaces standard rendering with a strict two-tone wireframe/threshold visualization, simulating a monochromatic CRT monitor inside the game.

🖥️ Visual Style

The "P1" Phosphor Aesthetic

By default, the pack utilizes the "P1 Apple Green" (#33FF33) color scheme, mimicking the high-persistence green phosphor monitors of the Apple II era. The world is rendered as a stark contrast between illuminated geometry and a pure black void.

CRT Emulation

The pack includes a fully procedural CRT post-processing stack:

Screen Curvature: subtle geometric distortion to mimic a curved glass tube.
Scanlines: Horizontal beam lines that scroll slowly with time.
Chromatic Aberration: Slight RGB channel separation at the screen edges.
Vignette: darkening at the corners to simulate tube depth.

⚙️ Technical Features

Depth-Based Rendering: Uses Sobel Edge Detection and luminance thresholding on the depth buffer to generate outlines and solids.
Optimization Friendly: Extremely low GPU overhead. Disables standard lighting, shadows, and PBR calculations.
"Hall of Mirrors" Fix: Includes a custom Sky Shader module that forces a depth buffer clear. This prevents the "smearing" artifacts common when using optimization mods (like Radon/Sodium) that disable vanilla sky rendering.
Driver Support: Compatible with both NVIDIA and AMD GPUs (OpenGL 3.0+).

🎛️ Configuration

While the default is Green, the pack is fully configurable via the Shader Options menu in-game.

RGB Color Channels

You can manually mix the phosphor color using 0-255 sliders.

Classic Amber: R: 255, G: 176, B: 0
Macintosh White: R: 229, G: 251, B: 255
Neon Purple: R: 214, G: 3, B: 220

World Settings

Contrast Threshold: Controls the sensitivity of the edge detector (higher = darker world, lower = more noise).
Void Distance: Sets the strict cutoff distance where the grid fades into black.
CRT Effects: Sliders to adjust or disable Curvature, Scanline Intensity, and Aberration.

⚠️ Known Issues & Troubleshooting

The "Hall of Mirrors" (Smearing) Effect

If you see the screen "smearing" or trails following your movement, your Depth Buffer is not being cleared correctly.

The Cause: This usually happens with high-performance custom clients or mods that disable the vanilla sky rendering to save FPS. Without the sky pass, the command to clear the previous frame's depth data is never sent.
The Fix:
1. Ensure Sky Rendering is enabled in your client settings.
2. If you are a developer using a custom rendering engine, ensure the depth buffer bit is cleared at the start of the frame.

Items appear as "Blobs" or lack detail

If hand items look like solid blocks of color:

Adjust the Contrast Threshold in the shader options.
Lowering the threshold will make the detector more sensitive to smaller depth changes, revealing more detail on close-up objects.

📥 Installation

Download the .zip file.
Place it into your .minecraft/shaderpacks folder.
Launch the game using Iris or OptiFine.
Select CRT Monochrome Shaderpack from the Shader list.

Note: For the best experience, ensure "Render Regions" is enabled if using OptiFine.

📣 Streaming & Content Creation

If you feature this shader pack in a stream or video, please provide credit by linking to the official project page or mentioning h1ggsk. I’d love to see what you create with it!

📦 Modpack Policy

Permission Granted: You are free to include the CRT Monochrome Shaderpack in modpacks hosted on CurseForge or Modrinth.
Requirement: The modpack must use the official project dependency/link so that downloads are tracked through the original source.
Prohibited: You may not re-upload the shader pack as a standalone file or host it on third-party "mirror" sites.

📄 License

This software is the intellectual property of h1ggsk.

Non-Redistribution: You may not re-upload, mirror, or redistribute this shader pack as a standalone project.
Modification: You may modify the code for personal use only. You may not distribute modified versions of the code ("forks") without explicit written permission from the author.
Modpack Exception: Use in curated modpacks is permitted under the conditions outlined in the "Modpack Policy" above.

CRT Monochrome Shaders