godot-shaders

1# Godot Shaders (4.x)
2 
3Write `canvas_item` (2D) and `spatial` (3D) shaders in the Godot Shading Language, animate
4with `TIME`/`UV`, expose `uniform`s, and read the screen. Targets **Godot 4.7**.
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6## When to use
7 
8- Use when writing `.gdshader` code or a `ShaderMaterial`: 2D effects (outline, dissolve,
9  flash, water), 3D surface shaders (rim light, toon, scrolling UV), or screen-space
10  post effects.
11 
12**When *not* to use:** the cross-engine *concepts* of shading (UVs, vertex/fragment
13theory) → `shader-programming`; particles/VFX nodes → general 3D; non-shader visuals.
14 
15## Core workflow
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171. **Pick the shader type** on the first line: `shader_type canvas_item;` for 2D
18   (Sprite2D, TextureRect, anything `CanvasItem`) or `shader_type spatial;` for 3D
19   materials. (`particles`, `sky`, `fog` also exist.)
202. **Attach via a `ShaderMaterial`.** Create a `ShaderMaterial`, assign your `.gdshader`,
21   and put it on the node's `material`. Uniforms appear in the Inspector.
223. **Write `fragment()`** to set the output: `COLOR` (2D) or `ALBEDO`/`EMISSION`/`ALPHA`
23   (3D). Optionally `vertex()` to move geometry and `light()` for custom lighting.
244. **Expose tunables as `uniform`s** with hints (`source_color`, `hint_range`) so they are
25   editable and correctly color-managed.
265. **Animate with the built-in `TIME`** and sample textures with `texture(tex, UV)`.
276. **Set uniforms from code** with `material.set_shader_parameter("name", value)`.
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29## Patterns
30…