Minecraft Shaders Wiki

Minecraft core shaders are categorized into two main types: Non-Rendertype and Rendertype.

• Non-Rendertype: General-purpose shaders that target broad elements like the sky, particles, or UI. These are not prefixed with rendertype_.
• Rendertype: Shaders targeted at specific rendering elements (e.g., blocks, entities, UI). These are always prefixed with rendertype_.

Use the shader type to determine which part of the game world or interface you can modify.

Vanilla Minecraft shaders are located within the assets/minecraft/shaders directory of a resource pack. The shaders folder is organized into four primary subfolders:

• core: Contains core shaders responsible for rendering most game elements (e.g., GUI elements, blocks).
• post: Contains post-processing shaders.
• program: Contains shader programs.
• include: Contains shader include files.

You can find a copy of the vanilla shader files in the mcmeta repository.

Rendertype block shaders are used to modify how specific types of blocks appear.

• rendertype_solid: Targets all solid blocks, lava, and (in fast mode) leaves. It also affects non-translucent falling blocks.
• rendertype_cutout: Targets most non-cube-hitbox blocks. Refer to the specific block list for details.

Non-Rendertype shaders target broad game elements. Common shaders include:

• blit_screen: Copies one buffer to another. Note: This cannot be overridden in a resource pack.
• particle: Affects weather (snow/rain) and all particles. The alpha value in the shader overrides the particle's inbuilt transparency (e.g., for sneeze particles).
• position: Affects the color of the sky and text highlighting.
• position_color: Handles sunset/sunrise sky overlays and F3+G chunk border displays. In versions prior to 1.20, it also handled various UI backgrounds (chat, pause menu, etc.).
• position_tex: Handles the Sun, Moon, worldborder, most GUI textures (hotbar, buttons), overlays (pumpkin blur, vignette), and the crosshair.
• position_tex_color: Handles the End sky, main menu backgrounds, fire overlays, and wall overlays.

Core shaders and post-processing shaders typically consist of three distinct file types that work together:

1. .vsh (Vertex Shader): Handles the processing of vertices.
2. .fsh (Fragment Shader): Handles the processing of pixels/fragments.
3. .json: A configuration file that defines how the shaders are linked and used.

Note that post-processing shaders often share a single vertex shader across multiple fragment shaders.

In this shader system, blocks are categorized into three transparency types: solid, cutout_mipped, cutout, and translucent. Any block not explicitly listed in the cutout_mipped, cutout, or translucent categories is treated as solid.

Understanding these categories is essential for determining how shaders will render specific block textures and their alpha channels.

The GameTime uniform is a constantly incrementing value synchronized with the server. It ranges from 0 to 1, repeating every 24,000 ticks (approximately 20 minutes).

To create a loop that repeats roughly every second, use fract(GameTime * 1200).

Note: Because it is synchronized with the server, it is affected by tick lag and may not be perfectly consistent.

// Example: looping effect every ~1 second
float timeLoop = fract(GameTime * 1200.0);

In Entity Shaders, the Position uniform represents the XYZ coordinates in view-space (relative to the camera).

To get the actual vector position in world space, you must add the ChunkOffset to the Position and then multiply the result by the ModelViewMatrix.

Formula: WorldPosition = ModelViewMat * (Position + ChunkOffset)

// Entity Shader world position calculation
vec3 worldPos = ModelViewMat * (Position + ChunkOffset);

When working with UI-related shaders like position_color or position_tex, the Position value is calculated as the screen size divided by the GUI scale.

Example: If the screen resolution is 1920x1080 and the GUI scale is set to 3, the Position range will be:

• x: [0, 640]
• y: [0, 360]