Fullscreen Shader Graphs and Custom Textures
Since 2.2.0
A resource can expose sampler parameters for LUTs, noise, ramps, or mod-provided textures.
Fullscreen Graph uses the same typed node system as particle Shader Graph, but its geometry is a full-screen quad and its inputs come from Render Graph pass ports.
Coordinates
- Fullscreen Position provides the full-screen vertex basis and normalized UV.
- Texel Size returns the reciprocal target size; multiply it by pixel offsets for blur, outline, or chromatic aberration.
- Scene/depth reconstruction nodes use the camera state captured for the pass.
Never hard-code a screen resolution. Preview, window resizing, UI scale, and half-resolution passes all change actual target size.
Exposed Inputs
| Graph variable | Pass port/use |
|---|---|
| Sampler/Texture | Wire Scene Color, depth-derived texture, previous pass, or Texture Input |
| float | radius, strength, threshold, time scale |
| vec2 | direction, center, distortion scale |
| vec3/vec4/color | tint, channel weights, outline color |
Weight is engine-managed and is not exposed as an ordinary pass port. Use the Effect Weight node when the shader must participate in blending internally.
External Textures
LUTs, blue noise, ramps, lens dirt, and other images can enter through Texture Input. Keep them in the project/FX Pack namespace and document expected filtering/wrap behavior. A LUT's dimensions and packing are part of the effect contract; replacing it with an arbitrary image will not produce a meaningful result.
Graph Pass vs Core Shader Pass
| Fullscreen Graph | Hand-written Core Shader |
|---|---|
| Visual editing and typed connections | Direct GLSL control |
| Exposed variables define ports | JSON samplers/uniforms are introspected |
| Compiler supplies stage plumbing | Author owns JSON/VSH/FSH compatibility |
| Easier resource refactoring | Easier to port established shaders |
Both sources run on the same full-screen quad and target pool, and can be mixed in one Render Graph.
See Hand-written Fullscreen Shaders for JSON reflection rules, sampler ports, and engine uniforms.
Common Multi-pass Patterns
Blur: Scene -> horizontal half-res pass -> vertical half-res pass -> Output
Bloom-like: Scene -> bright pass -> downsample/blur chain -> add-mix with Scene
Outline: Scene Depth -> edge pass; Scene Color + edge -> composite -> Output
LUT: Scene -> color lookup pass -> Output