Framebuffers can be used globally with the FramebufferManager, and also with post-processing. Globally scoped framebuffers are located in the framebuffers folder in the resource pack. These can be used in post-processing to move data between stages.

Format

There is a short and long form of the buffer format. The short version only has 1 color buffer and an optional depth buffer. The long version allows full customization of all color buffers and an optional depth buffer. There must be at least 1 color buffer! It is not valid to have a depth-only framebuffer.

Long-Form

{
  // Optional
  // This is a MoLang expression
  "width": "q.screen_width",
  // Optional
  // This is a MoLang expression
  "height": "q.screen_height",
  // Optional
  // Whether the buffer should be automatically cleared at the start of every frame
  "autoClear": true,
  // Required
  "color_buffers": [
    {
      // Optional
      // "texture" or "render_buffer"
      "type": "texture",
      // Optional
      // The OpenGL format to use
      "format": "RGBA8",
      // Optional
      // The number of mipmaps for textures and samples for render buffers. This must be at least 0
      "levels": 0,
      // Optional
      // Whether to use linear or nearest filtering
      "linear": false,
      // Optional
      // The custom name to use when uploading this as a sampler to shaders
      "name": "AwesomeColorBuffer"
    }
  ],
  // See #Depth
  "depth": ...,
}

Short-Form

{
  // Optional
  // This is a MoLang expression
  "width": "q.screen_width",
  // Optional
  // This is a MoLang expression
  "height": "q.screen_height",
  // Optional
  // Whether the buffer should be automatically cleared at the start of every frame
  "autoClear": true,
  // Optional
  // "texture" or "render_buffer"
  "type": "texture",
  // Optional
  // The OpenGL format to use
  "format": "RGBA8",
  // Optional
  // The number of mipmaps for textures and samples for render buffers. This must be at least 0
  "levels": 0,
  // Optional
  // Whether to use linear or nearest filtering
  "linear": false,
  // Optional
  // The custom name to use when uploading this as a sampler to shaders
  "name": "AwesomeColorBuffer",
  // See #Depth
  "depth": ...,
}

Depth

Depth can either be a boolean to add a depth buffer, or a full attachment definition.

{
  "depth": true
}

OR

{
  "depth": {
    // Optional
    // "texture" or "render_buffer"
    "type": "texture",
    // Optional
    // The OpenGL format to use
    "format": "DEPTH_COMPONENT",
    // Optional
    // The number of mipmaps for textures and samples for render buffers. This must be at least 0
    "levels": 0,
    // Optional
    // Whether to use linear or nearest filtering
    "linear": false,
    // Optional
    // The custom name to use when uploading this as a sampler to shaders
    "name": "AwesomeDepthBuffer"
  }
}

Notes

When using an integer or floating point format, make SURE the data type is set appropriately. It may or may not work on some systems, but most drivers will refuse to draw into a buffer if the data type is mismatched!

All parameters in framebuffer definitions are optional to make it very easy to create new quick buffers. For example, the following is a valid framebuffer definition:

{
  "depth": true
}

This creates a framebuffer the size of the window. It has a single color texture attachment using RGBA8 and 0 mipmap levels. It also has a depth texture buffer using DEPTH_COMPONENT.

Setting name in a texture attachment will only add an alias binding. This means:

{
  "depth": true,
  "color_buffers": [
    {
      "name": "AlbedoSampler",
      "format": "RGBA8"
    },
    {
      "name": "NormalSampler",
      "format": "RGB16F"
    },
    {
      "name": "MaterialSampler",
      "format": "R16F"
    },
    {
      "name": "EmissiveSampler",
      "format": "RGBA8"
    },
    {
      "name": "VanillaLightSampler",
      "format": "RG8"
    }
  ]
}

can reference AlbedoSampler in the shader. For example:

// Both of these reference the same texture
uniform sampler2D DiffuseSampler0;
uniform sampler2D AlbedoSampler;

linear and name only work for texture attachment types. Any other types ignore this parameter (since you can’t sample render buffers).