---
id: gamedev-skills/awesome-gamedev-agent-skills/godot-shaders
version: "5406ee91"
license: Apache-2.0
install: manual
updated: 2026-07-25
---

# godot-shaders — Master Godot 4.x shader development with this skill focused on GDShader language fundamentals. Write, test, and debug custom shaders to create stunning visual effects and materials for your games. Leverage SkillFed's integrated tooling to accelerate shader iteration and solve rendering challenges efficiently.

Publisher: gamedev-skills · Stars: 356 · Updated: 2026-07-25

Install (manual): `git clone https://github.com/gamedev-skills/awesome-gamedev-agent-skills`

## SKILL.md

# Godot Shaders (4.x)

Write `canvas_item` (2D) and `spatial` (3D) shaders in the Godot Shading Language, animate
with `TIME`/`UV`, expose `uniform`s, and read the screen. Targets **Godot 4.3+**.

## When to use

- Use when writing `.gdshader` code or a `ShaderMaterial`: 2D effects (outline, dissolve,
  flash, water), 3D surface shaders (rim light, toon, scrolling UV), or screen-space
  post effects.

**When *not* to use:** the cross-engine *concepts* of shading (UVs, vertex/fragment
theory) → `shader-programming`; particles/VFX nodes → general 3D; non-shader visuals.

## Core workflow

1. **Pick the shader type** on the first line: `shader_type canvas_item;` for 2D
   (Sprite2D, TextureRect, anything `CanvasItem`) or `shader_type spatial;` for 3D
   materials. (`particles`, `sky`, `fog` also exist.)
2. **Attach via a `ShaderMaterial`.** Create a `ShaderMaterial`, assign your `.gdshader`,
   and put it on the node's `material`. Uniforms appear in the Inspector.
3. **Write `fragment()`** to set the output: `COLOR` (2D) or `ALBEDO`/`EMISSION`/`ALPHA`
   (3D). Optionally `vertex()` to move geometry and `light()` for custom lighting.
4. **Expose tunables as `uniform`s** with hints (`source_color`, `hint_range`) so they are
   editable and correctly color-managed.
5. **Animate with the built-in `TIME`** and sample textures with `texture(tex, UV)`.
6. **Set uniforms from code** with `material.set_shader_parameter("name", value)`.

## Patterns

### 1. 2D (canvas_item): tint + scrolling UV

```glsl
shader_type canvas_item;

uniform vec4 tint : source_color = vec4(1.0);     // source_color = sRGB-correct color
uniform float scroll_speed : hint_range(0.0, 2.0) = 0.3;

void fragment() {
    vec2 uv = UV;
    uv.x += TIME * scroll_speed;                  // scroll horizontally over time
    COLOR = texture(TEXTURE, uv) * tint;          // TEXTURE = the node's texture
}
```

### 2. 2D dissolve using a noise threshold

```glsl
shader_type canvas_item;

uniform sampler2D noise : repeat_enable;          // a NoiseTexture2D
uniform float amount : hint_range(0.0, 1.0) = 0.0;

void fragment() {
    vec4 tex = texture(TEXTURE, UV);
    float n = texture(noise, UV).r;
    if (n < amount) {
        discard;                                  // cut the pixel away
    }
    COLOR = tex;
}
```

### 3. 3D (spatial): emissive rim light

```glsl
shader_type spatial;

uniform vec4 base_color : source_color = vec4(0.2, 0.5, 1.0, 1.0);
uniform vec3 rim_color : source_color = vec3(0.6, 0.8, 1.0);
uniform float rim_power : hint_range(0.5, 8.0) = 3.0;

void fragment() {
    ALBEDO = base_color.rgb;
    // VIEW and NORMAL are view-space built-ins; rim is strong at grazing angles.
    float rim = pow(1.0 - dot(NORMAL, VIEW), rim_power);
    EMISSION = rim_color * rim;
}
```

### 4. Screen-reading post effect (4.x hint, not SCREEN_TEXTURE)

```glsl
shader_type canvas_item;

// 4.x: declare the screen as a uniform with hint_screen_texture.
uniform sampler2D screen_tex : hint_screen_texture, filter_linear_mipmap;
uniform float blur : hint_range(0.0, 4.0) = 1.0;

void fragment() {
    vec2 px = SCREEN_PIXEL_SIZE * blur;
    vec4 c = texture(screen_tex, SCREEN_UV);
    c += texture(screen_tex, SCREEN_UV + vec2(px.x, 0.0));
    c += texture(screen_tex, SCREEN_UV - vec2(px.x, 0.0));
    COLOR = c / 3.0;
}
```

Set a uniform from GDScript:

```gdscript
$Sprite2D.material.set_shader_parameter("amount", 0.7)
```

## Pitfalls

- **3.x → 4.x renames.** `SCREEN_TEXTURE` is removed — declare
  `uniform sampler2D x : hint_screen_texture;` and sample with `SCREEN_UV`. Color hints
  `hint_color`→`source_color`; `hint_albedo`/`hint_white`→`source_color`;
  `hint_range` stays. Depth/normal use `hint_depth_texture` / `hint_normal_roughness_texture`.
- **Wrong output variable.** In `canvas_item` write `COLOR`; in `spatial` write `ALBEDO`
  (and `EMISSION`, `ALPHA`, `ROUGHNESS`, `METALLIC`). Writing `COLOR` in a spatial shader
  does nothing.
- **Color uniforms without `source_color`** are treated as raw linear values and look
  wrong (washed/dark) because Godot won't sRGB-convert them.
- **Transparency needs opt-in (3D).** For `ALPHA < 1.0` to blend, add a render mode or set
  the material transparency; otherwise it's opaque/cut.
- **Sampling outside [0,1] UV** without `repeat_enable` clamps. Add `: repeat_enable` to
  the sampler uniform for tiling/scroll.
- **`TIME` is seconds since start** and keeps growing — wrap with `fract()`/`mod()` for
  periodic effects to avoid precision drift.
- **`discard` is costly** on some hardware and breaks early-Z; prefer setting `ALPHA`/
  `COLOR.a` when you can.

## References

- For built-in variables per shader type, render modes, `varying`, custom `light()`,
  `vertex()` displacement, and the visual shader graph, read
  `references/shading-language.md`.

## Related skills

- `shader-programming` — engine-agnostic shader concepts (GLSL/HLSL).
- `godot-3d-essentials` — materials, environment, and where spatial shaders live.
- `godot-ui-control` — applying shaders to UI for effects.


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