Up to date

This page is up to date for Godot 4.2. If you still find outdated information, please open an issue.

Langue de shading

Introduction

Godot utilise un langage de shading semblable à celui de GLSL ES 3.0. La plupart des types de données et des fonctions sont pris en charge, et les quelques autres seront probablement ajoutés au fil du temps.

Si vous êtes déjà familier avec GLSL, le Godot Shader Migration Guide est une ressource qui vous aidera à faire la transition entre GLSL normal et le langage de shading de Godot.

types

La plupart des types de GLSL ES 3.0 sont supportés :

Type	Description
void	Type void, seulement utile pour les fonctions ne retournant rien.
bool	Type de données booléen, ne peut contenir que true ou false.
bvec2	vecteur à deux composants de booléens.
bvec3	Vecteur de booléens à trois composants.
bvec4	Vecteur de booléens à quatre composants.
int	Entier scalaire signé.
ivec2	Vecteur d'entier signé (int) à deux composants.
ivec3	Vecteur d'entier signé (int) à trois composants.
ivec4	Vecteur d'entier signé (int) à quatre composants.
uint	Entier scalaire non-signé ; ne peut contenir de nombre négatif.
uvec2	Vecteur d'entier non-signé (unsigned int) à deux composants.
uvec3	Vecteur d'entier non-signé (unsigned int) à trois composants.
uvec4	Vecteur d'entier non-signé (unsigned int) à quatre composants.
float	Scalaire à virgule flottante.
vec2	Vecteur à deux composantes de valeurs à virgule flottante.
vec3	Vecteur à trois composantes de valeurs à virgule flottante.
vec4	Vecteur à quatre composantes de valeurs à virgule flottante.
mat2	Matrice 2x2, dans l'ordre principal des colonnes.
mat3	Matrice 3x3, dans l'ordre principal des colonnes.
mat4	Matrice 4x4, dans l'ordre principal des colonnes.
sampler2D	Type d'échantillonneur pour lier des textures 2D, qui sont lues comme des flottants.
isampler2D	Type d'échantillonneur pour lier des textures 2D, qui sont lues comme des entiers signés.
usampler2D	Type d'échantillonneur pour lier des textures 2D, qui sont lues comme des entiers non signés.
Sampler2DArray	Type d'échantillonneur pour lier des tableaux de textures 2D, qui sont lues comme des flottants.
isampler2DArray	Type d'échantillonneur pour lier des tableaux de textures 2D, qui sont lues comme des entiers signés.
usampler2DArray	Type d'échantillonneur pour lier des tableaux de textures 2D, qui sont lues comme des entiers non signés.
sampler3D	Type d'échantillonneur pour lier des textures 3D, qui sont lues comme des flottants.
isampler3D	Type d'échantillonneur pour lier des textures 3D, qui sont lues comme des entiers signés.
usampler3D	Type d'échantillonneur pour lier des textures 3D, qui sont lues comme des entiers non signés.
samplerCube	Sampler type for binding Cubemaps, which are read as float.
samplerCubeArray	Sampler type for binding Cubemap arrays, which are read as float.

Conversion de type

Comme dans GLSL ES 3.0, les conversions (casts) implicites entre sclaires et vecteurs de la même taille mais de type différent sont interdites. La conversion de type de différentes tailles est aussi interdite. Les conversions doivent être faites explicitement via les constructeurs.

Exemple :

float a = 2; // invalid
float a = 2.0; // valid
float a = float(2); // valid

Les entiers de base sont signés, ce qui oblige l'utilisation des casts pour convertir en non-signé :

int a = 2; // valid
uint a = 2; // invalid
uint a = uint(2); // valid

Membres

Les membre scalaires des types vecteurs sont accessible par les membres "x", "y", "z" et "w". Cependant, utiliser "r", "g", "b" et "a" fonctionne aussi et est équivalent. Utilisez ce qui correspond le mieux à vos besoins.

Pour les matrices utilisez la syntaxe d'indexation m[ligne][colonne] pour accéder à chaque scalaire, ou m[idx] pour accéder à un vecteur par. Par exemple, pour accéder à la position y d'un objet de type mat4 utilisez m[3][1].

Construction

La construction de vecteurs doit toujours passer :

// The required amount of scalars
vec4 a = vec4(0.0, 1.0, 2.0, 3.0);
// Complementary vectors and/or scalars
vec4 a = vec4(vec2(0.0, 1.0), vec2(2.0, 3.0));
vec4 a = vec4(vec3(0.0, 1.0, 2.0), 3.0);
// A single scalar for the whole vector
vec4 a = vec4(0.0);

La construction des types matrice nécessite des vecteurs de même dimension que la matrice. Vous pouvez également construire une matrice diagonale en utilisant la syntaxe matx (float). Par conséquent, mat4 (1.0) est une matrice identité.

mat2 m2 = mat2(vec2(1.0, 0.0), vec2(0.0, 1.0));
mat3 m3 = mat3(vec3(1.0, 0.0, 0.0), vec3(0.0, 1.0, 0.0), vec3(0.0, 0.0, 1.0));
mat4 identity = mat4(1.0);

Matrices can also be built from a matrix of another dimension. There are two rules:

1. If a larger matrix is constructed from a smaller matrix, the additional rows and columns are set to the values they would have in an identity matrix. 2. If a smaller matrix is constructed from a larger matrix, the top, left submatrix of the larger matrix is used.

mat3 basis = mat3(MODEL_MATRIX);
mat4 m4 = mat4(basis);
mat2 m2 = mat2(m4);

Mélange

Il est possible d'obtenir n'importe quelle combinaison de composants dans n'importe quel ordre, tant que le résultat est un autre type vecteur (ou scalaire). C'est plus facile à montrer qu'à expliquer :

vec4 a = vec4(0.0, 1.0, 2.0, 3.0);
vec3 b = a.rgb; // Creates a vec3 with vec4 components.
vec3 b = a.ggg; // Also valid; creates a vec3 and fills it with a single vec4 component.
vec3 b = a.bgr; // "b" will be vec3(2.0, 1.0, 0.0).
vec3 b = a.xyz; // Also rgba, xyzw are equivalent.
vec3 b = a.stp; // And stpq (for texture coordinates).
float c = b.w; // Invalid, because "w" is not present in vec3 b.
vec3 c = b.xrt; // Invalid, mixing different styles is forbidden.
b.rrr = a.rgb; // Invalid, assignment with duplication.
b.bgr = a.rgb; // Valid assignment. "b"'s "blue" component will be "a"'s "red" and vice versa.

Précision

Il est possible d'ajouter des modificateurs de précision aux types de données. Utilisez-les pour les uniformes, les variables, les arguments et les varyings :

lowp vec4 a = vec4(0.0, 1.0, 2.0, 3.0); // low precision, usually 8 bits per component mapped to 0-1
mediump vec4 a = vec4(0.0, 1.0, 2.0, 3.0); // medium precision, usually 16 bits or half float
highp vec4 a = vec4(0.0, 1.0, 2.0, 3.0); // high precision, uses full float or integer range (default)

L'utilisation d'une précision inférieure pour certaines opérations peut accélérer les calculs (au prix d'une moindre précision). Ceci est rarement nécessaire dans la fonction de processeur de vertex (où la précision maximum est nécessaire la plupart du temps), mais c'est souvent utile dans le processeur de fragment.

Certaines architectures (principalement mobiles) peuvent en bénéficier de manière significative, mais il y a des inconvénients tels que le surcoût de la conversion entre les précisions. Pour plus d'informations, veuillez vous reporter à la documentation de l'architecture cible. Dans de nombreux cas, les pilotes mobiles provoquent un comportement incohérent ou inattendu et il est préférable d'éviter de spécifier la précision, sauf si cela s'avère nécessaire.

Les tableaux

Arrays are containers for multiple variables of a similar type.

Tableaux locaux

Les tableaux locaux sont déclarés dans les fonctions. Ils peuvent utiliser tous les types de données autorisés, sauf les samplers. La déclaration du tableau suit une syntaxe de type C : [const] + [precision] + typename + identifier + [array size].

void fragment() {
    float arr[3];
}

Ils peuvent être initialisés au début comme cela :

float float_arr[3] = float[3] (1.0, 0.5, 0.0); // first constructor

int int_arr[3] = int[] (2, 1, 0); // second constructor

vec2 vec2_arr[3] = { vec2(1.0, 1.0), vec2(0.5, 0.5), vec2(0.0, 0.0) }; // third constructor

bool bool_arr[] = { true, true, false }; // fourth constructor - size is defined automatically from the element count

Vous pouvez déclarer plusieurs tableaux (même avec des tailles différentes) dans une expression :

float a[3] = float[3] (1.0, 0.5, 0.0),
b[2] = { 1.0, 0.5 },
c[] = { 0.7 },
d = 0.0,
e[5];

Pour accéder à un élément de tableau, utilisez la syntaxe d'indexation :

float arr[3];

arr[0] = 1.0; // setter

COLOR.r = arr[0]; // getter

Les tableaux ont aussi une fonction intégrée .length() (à ne pas confondre avec la fonction intégrée length()). Il n'accepte aucun paramètre et retourne la taille du tableau.

float arr[] = { 0.0, 1.0, 0.5, -1.0 };
for (int i = 0; i < arr.length(); i++) {
    // ...
}

Note

If you use an index either below 0 or greater than array size - the shader will crash and break rendering. To prevent this, use length(), if, or clamp() functions to ensure the index is between 0 and the array's length. Always carefully test and check your code. If you pass a constant expression or a number, the editor will check its bounds to prevent this crash.

Global arrays

You can declare arrays at global space like:

shader_type spatial;

const lowp vec3 v[1] = lowp vec3[1] ( vec3(0, 0, 1) );

void fragment() {
  ALBEDO = v[0];
}

Note

Global arrays have to be declared as global constants, otherwise they can be declared the same as local arrays.

Constantes

Utilisez le mot-clé const avant la déclaration de la variable pour rendre cette variable immuable, ce qui signifie qu'elle ne peut pas être modifiée. Tous les types de base, sauf les samplers, peuvent être déclarés comme des constantes. L'accès et l'utilisation d'une valeur constante est légèrement plus rapide que l'utilisation d'un uniforme. Les constantes doivent être initialisées lors de leur déclaration.

const vec2 a = vec2(0.0, 1.0);
vec2 b;

a = b; // invalid
b = a; // valid

Les constantes ne peuvent pas être modifiées et ne peuvent pas non plus avoir d'indices, mais plusieurs d'entre elles (si elles ont le même type) peuvent être déclarées dans une seule expression, par exemple

const vec2 V1 = vec2(1, 1), V2 = vec2(2, 2);

Comme les variables, les tableaux peuvent aussi être déclarés avec const.

const float arr[] = { 1.0, 0.5, 0.0 };

arr[0] = 1.0; // invalid

COLOR.r = arr[0]; // valid

Les constantes peuvent être déclarées à la fois globalement (en dehors de toute fonction) ou localement (à l'intérieur d'une fonction). Les constantes globales sont utiles lorsque vous voulez avoir accès à une valeur dans tout votre shader qui n'a pas besoin d'être modifiée. Comme les uniformes, les constantes globales sont partagées entre tous les étages de shaders, mais elles ne sont pas accessibles en dehors du shader.

shader_type spatial;

const float PI = 3.14159265358979323846;

Constants of the float type must be initialized using . notation after the decimal part or by using the scientific notation. The optional f post-suffix is also supported.

float a = 1.0;
float b = 1.0f; // same, using suffix for clarity
float c = 1e-1; // gives 0.1 by using the scientific notation

Constants of the uint (unsigned int) type must have a u suffix to differentiate them from signed integers. Alternatively, this can be done by using the uint(x) built-in conversion function.

uint a = 1u;
uint b = uint(1);

Structs

Structs are compound types which can be used for better abstraction of shader code. You can declare them at the global scope like:

struct PointLight {
    vec3 position;
    vec3 color;
    float intensity;
};

After declaration, you can instantiate and initialize them like:

void fragment()
{
    PointLight light;
    light.position = vec3(0.0);
    light.color = vec3(1.0, 0.0, 0.0);
    light.intensity = 0.5;
}

Or use struct constructor for same purpose:

PointLight light = PointLight(vec3(0.0), vec3(1.0, 0.0, 0.0), 0.5);

Structs may contain other struct or array, you can also instance them as global constant:

shader_type spatial;

...

struct Scene {
    PointLight lights[2];
};

const Scene scene = Scene(PointLight[2](PointLight(vec3(0.0, 0.0, 0.0), vec3(1.0, 0.0, 0.0), 1.0), PointLight(vec3(0.0, 0.0, 0.0), vec3(1.0, 0.0, 0.0), 1.0)));

void fragment()
{
    ALBEDO = scene.lights[0].color;
}

You can also pass them to functions:

shader_type canvas_item;

...

Scene construct_scene(PointLight light1, PointLight light2) {
    return Scene({light1, light2});
}

void fragment()
{
    COLOR.rgb = construct_scene(PointLight(vec3(0.0, 0.0, 0.0), vec3(1.0, 0.0, 0.0), 1.0), PointLight(vec3(0.0, 0.0, 0.0), vec3(1.0, 0.0, 1.0), 1.0)).lights[0].color;
}

Opérateurs

Le langage de shading de Godot prend en charge le même ensemble d'opérateurs que GLSL ES 3.0. Vous trouverez ci-dessous la liste de ces derniers par ordre de priorité :

Priorité	Classe	Opérateur
1 (le plus élevé)	groupement entre parenthèses	()
2	unaire	+, -, !, ~
3	multiplicatif	/, *, %
4	additif	+, -
5	décalage par bits	<<, >>
6	relationnel	<, >, <=, >=
7	égalité	==, !=
8	bit-wise ET	&
9	bit-wise OU exclusif	^
10	bit-wise OU inclusif	|
11	ET logique	&&
12 (le plus bas)	OU inclusif logique	||

Contrôle de flux

Le langage de Shading de Godot prend en charge les types de contrôle de flux les plus courants :

// `if` and `else`.
if (cond) {

} else {

}

// Ternary operator.
// This is an expression that behaves like `if`/`else` and returns the value.
// If `cond` evaluates to `true`, `result` will be `9`.
// Otherwise, `result` will be `5`.
int result = cond ? 9 : 5;

// `switch`.
switch (i) { // `i` should be a signed integer expression.
    case -1:
        break;
    case 0:
        return; // `break` or `return` to avoid running the next `case`.
    case 1: // Fallthrough (no `break` or `return`): will run the next `case`.
    case 2:
        break;
    //...
    default: // Only run if no `case` above matches. Optional.
        break;
}

// `for` loop. Best used when the number of elements to iterate on
// is known in advance.
for (int i = 0; i < 10; i++) {

}

// `while` loop. Best used when the number of elements to iterate on
// is not known in advance.
while (cond) {

}

// `do while`. Like `while`, but always runs at least once even if `cond`
// never evaluates to `true`.
do {

} while (cond);

Keep in mind that in modern GPUs, an infinite loop can exist and can freeze your application (including editor). Godot can't protect you from this, so be careful not to make this mistake!

Also, when comparing floating-point values against a number, make sure to compare them against a range instead of an exact number.

A comparison like if (value == 0.3) may not evaluate to true. Floating-point math is often approximate and can defy expectations. It can also behave differently depending on the hardware.

Don't do this.

float value = 0.1 + 0.2;

// May not evaluate to `true`!
if (value == 0.3) {
    // ...
}

Instead, always perform a range comparison with an epsilon value. The larger the floating-point number (and the less precise the floating-point number), the larger the epsilon value should be.

const float EPSILON = 0.0001;
if (value >= 0.3 - EPSILON && value <= 0.3 + EPSILON) {
    // ...
}

See floating-point-gui.de for more information.

Jeter

Fragment and light functions can use the discard keyword. If used, the fragment is discarded and nothing is written.

Beware that discard has a performance cost when used, as it will prevent the depth prepass from being effective on any surfaces using the shader. Also, a discarded pixel still needs to be rendered in the vertex shader, which means a shader that uses discard on all of its pixels is still more expensive to render compared to not rendering any object in the first place.

Fonctions

Il est possible de définir des fonctions dans un shader Godot. Elles utilisent la syntaxe suivante :

ret_type func_name(args) {
    return ret_type; // if returning a value
}

// a more specific example:

int sum2(int a, int b) {
    return a + b;
}

You can only use functions that have been defined above (higher in the editor) the function from which you are calling them. Redefining a function that has already been defined above (or is a built-in function name) will cause an error.

Les arguments de fonction peuvent avoir des qualificateurs spéciaux :

• in : Signifie que l'argument est seulement en lecture seule (par défaut).

• out : Cela signifie que l'argument est en écriture seule.

• inout : Signifie que l'argument est entièrement passé par la référence.

• const: Means the argument is a constant and cannot be changed, may be combined with in qualifier.

Exemple ci-dessous :

void sum2(int a, int b, inout int result) {
    result = a + b;
}

Note

Unlike GLSL, Godot's shader language does not support function overloading. This means that a function cannot be defined several times with different argument types or numbers of arguments. As a workaround, use different names for functions that accept a different number of arguments or arguments of different types.

Varyings

Pour envoyer des données de la fonction de traitement de sommets à la fonction de traitement de fragments, des varyings sont utilisées. Ils sont définis pour chaque sommet primitif dans le traitement de sommets, et la valeur est interpolée pour chaque pixel dans le traitement de fragments.

shader_type spatial;

varying vec3 some_color;

void vertex() {
    some_color = NORMAL; // Make the normal the color.
}

void fragment() {
    ALBEDO = some_color;
}

void light() {
    DIFFUSE_LIGHT = some_color * 100; // optionally
}

Il est possible d'utiliser un tableau comme Varying :

shader_type spatial;

varying float var_arr[3];

void vertex() {
    var_arr[0] = 1.0;
    var_arr[1] = 0.0;
}

void fragment() {
    ALBEDO = vec3(var_arr[0], var_arr[1], var_arr[2]); // red color
}

Il est également possible d'envoyer des données depuis fragment vers les processeurs light en utilisant le mot clé varying. Pour ce faire, vous pouvez l'affecter dans fragment et l'utiliser plus tard dans la fonction light.

shader_type spatial;

varying vec3 some_light;

void fragment() {
    some_light = ALBEDO * 100.0; // Make a shining light.
}

void light() {
    DIFFUSE_LIGHT = some_light;
}

Notez qu'un varying ne peut pas être attribué dans les fonctions personnalisées ou dans un processeur de lumière comme :

shader_type spatial;

varying float test;

void foo() {
    test = 0.0; // Error.
}

void vertex() {
    test = 0.0;
}

void light() {
    test = 0.0; // Error too.
}

Cette limite a été introduite pour empêcher un usage incorrect avec l'initialisation.

Qualificateurs d'interpolation

Certaines valeurs sont interpolées pendant le pipeline de shading. Vous pouvez modifier la façon dont ces interpolations sont effectuées en utilisant les qualificateurs d'interpolation.

shader_type spatial;

varying flat vec3 our_color;

void vertex() {
    our_color = COLOR.rgb;
}

void fragment() {
    ALBEDO = our_color;
}

Il y a deux qualificateur d'interpolation possibles :

Qualificateur	Description
flat	La valeur n'est pas interpolée.
smooth	La valeur est interpolée de façon à corriger la perspective. C'est la valeur par défaut.

Uniforms

La transmission de valeurs aux shaders est possible. Ces dernieres sont globales à l'ensemble des shaders et sont appelés uniforms. Lorsqu'un shader est ultérieurement affecté à un matériau, les uniforms y apparaissent comme des paramètres modifiables. Les uniforms ne peuvent pas être écrites de l'intérieur du shader.

shader_type spatial;

uniform float some_value;

uniform vec3 colors[3];

Vous pouvez définir des uniforms dans l'éditeur du matériau. Ou vous pouvez les définir via GDScript :

material.set_shader_parameter("some_value", some_value)

material.set_shader_parameter("colors", [Vector3(1, 0, 0), Vector3(0, 1, 0), Vector3(0, 0, 1)])

Note

The first argument to set_shader_parameter is the name of the uniform in the shader. It must match exactly to the name of the uniform in the shader or else it will not be recognized.

Any GLSL type except for void can be a uniform. Additionally, Godot provides optional shader hints to make the compiler understand for what the uniform is used, and how the editor should allow users to modify it.

shader_type spatial;

uniform vec4 color : source_color;
uniform float amount : hint_range(0, 1);
uniform vec4 other_color : source_color = vec4(1.0); // Default values go after the hint.
uniform sampler2D image : source_color;

It's important to understand that textures that are supplied as color require hints for proper sRGB -> linear conversion (i.e. source_color), as Godot's 3D engine renders in linear color space. If this is not done, the texture will appear washed out.

Note

The 2D renderer also renders in linear color space if the Rendering > Viewport > HDR 2D project setting is enabled, so source_color must also be used in canvas_item shaders. If 2D HDR is disabled, source_color will keep working correctly in canvas_item shaders, so it's recommend to use it either way.

Liste complète des indices ci-dessous :

Type	Suggestion	Description
vec3, vec4	source_color	Utilisé comme couleur.
int, float	hint_range(min, max[, step])	Limité aux valeurs d'un intervalle (avec min/max/étape).
sampler2D	source_color	Used as albedo color.
sampler2D	hint_normal	Utilisé comme une NormalMap.
sampler2D	hint_default_white	As value or albedo color, default to opaque white.
sampler2D	hint_default_black	As value or albedo color, default to opaque black.
sampler2D	hint_default_transparent	As value or albedo color, default to transparent black.
sampler2D	hint_anisotropy	Comme flowmap, par défaut à droite.
sampler2D	hint_roughness[_r, _g, _b, _a, _normal, _gray]	Used for roughness limiter on import (attempts reducing specular aliasing). _normal is a normal map that guides the roughness limiter, with roughness increasing in areas that have high-frequency detail.
sampler2D	filter[_nearest, _linear][_mipmap][_anisotropic]	Enabled specified texture filtering.
sampler2D	repeat[_enable, _disable]	Enabled texture repeating.
sampler2D	hint_screen_texture	Texture is the screen texture.
sampler2D	hint_depth_texture	Texture is the depth texture.
sampler2D	hint_normal_roughness_texture	Texture is the normal roughness texture (only supported in Forward+).

GDScript utilise des types de variables différents de ceux de GLSL, donc lors du passage des variables de GDScript aux shaders, Godot convertit le type automatiquement. Vous trouverez ci-dessous un tableau des types correspondants :

type GLSL	Type GDScript	Notes
bool	bool
bvec2	int	Bitwise packed int where bit 0 (LSB) corresponds to x. For example, a bvec2 of (bx, by) could be created in the following way: bvec2_input: int = (int(bx)) | (int(by) << 1)
bvec3	int	Bitwise packed int where bit 0 (LSB) corresponds to x.
bvec4	int	Bitwise packed int where bit 0 (LSB) corresponds to x.
int	int
ivec2	Vector2i
ivec3	Vector3i
ivec4	Vector4i
uint	int
uvec2	Vector2i
uvec3	Vector3i
uvec4	Vector4i
float	float
vec2	Vector2
vec3	Vector3, Color	When Color is used, it will be interpreted as (r, g, b).
vec4	Vector4, Color, Rect2, Plane, Quaternion	When Color is used, it will be interpreted as (r, g, b, a). When Rect2 is used, it will be interpreted as (position.x, position.y, size.x, size.y). When Plane is used it will be interpreted as (normal.x, normal.y, normal.z, d).
mat2	Transform2D
mat3	Basis
mat4 mat4	Projection, Transform3D	When a Transform3D is used, the w Vector is set to the identity.
sampler2D	Texture2D
isampler2D	Texture2D
usampler2D	Texture2D
Sampler2DArray	Texture2DArray
isampler2DArray	Texture2DArray
usampler2DArray	Texture2DArray
sampler3D	Texture3D
isampler3D	Texture3D
usampler3D	Texture3D
samplerCube	Cubemap
samplerCubeArray	CubemapArray

Note

Faites attention lorsque vous définissez des uniforms de shader à partir de GDScript, aucune erreur ne sera lancée si le type ne correspond pas. Votre shader ne fera que présenter un comportement indéfini.

Des valeurs par défaut peuvent également être attribuées aux uniforms :

shader_type spatial;

uniform vec4 some_vector = vec4(0.0);
uniform vec4 some_color : source_color = vec4(1.0);

Note that when adding a default value and a hint, the default value goes after the hint.

If you need to make multiple uniforms to be grouped in the specific category of an inspector, you can use a group_uniform keyword like:

group_uniforms MyGroup;
uniform sampler2D test;

You can close the group by using:

group_uniforms;

The syntax also supports subgroups (it's not mandatory to declare the base group before this):

group_uniforms MyGroup.MySubgroup;

Global uniforms

Sometimes, you want to modify a parameter in many different shaders at once. With a regular uniform, this takes a lot of work as all these shaders need to be tracked and the uniform needs to be set for each of them. Global uniforms allow you to create and update uniforms that will be available in all shaders, in every shader type (canvas_item, spatial, particles, sky and fog).

Global uniforms are especially useful for environmental effects that affect many objects in a scene, like having foliage bend when the player is nearby, or having objects move with the wind.

To create a global uniform, open the Project Settings then go to the Shader Globals tab. Specify a name for the uniform (case-sensitive) and a type, then click Add in the top-right corner of the dialog. You can then edit the value assigned to the uniform by clicking the value in the list of uniforms:

Adding a global uniform in the Shader Globals tab of the Project Settings

After creating a global uniform, you can use it in a shader as follows:

shader_type canvas_item;

global uniform vec4 my_color;

void fragment() {
    COLOR = my_color.rgb;
}

Note that the global uniform must exist in the Project Settings at the time the shader is saved, or compilation will fail. While you can assign a default value using global uniform vec4 my_color = ... in the shader code, it will be ignored as the global uniform must always be defined in the Project Settings anyway.

To change the value of a global uniform at run-time, use the RenderingServer.global_shader_parameter_set method in a script:

RenderingServer.global_shader_parameter_set("my_color", Color(0.3, 0.6, 1.0))

Assigning global uniform values can be done as many times as desired without impacting performance, as setting data doesn't require synchronization between the CPU and GPU.

You can also add or remove global uniforms at run-time:

RenderingServer.global_shader_parameter_add("my_color", RenderingServer.GLOBAL_VAR_TYPE_COLOR, Color(0.3, 0.6, 1.0))
RenderingServer.global_shader_parameter_remove("my_color")

Adding or removing global uniforms at run-time has a performance cost, although it's not as pronounced compared to getting global uniform values from a script (see the warning below).

Avertissement

While you can query the value of a global uniform at run-time in a script using RenderingServer.global_shader_parameter_get("uniform_name"), this has a large performance penalty as the rendering thread needs to synchronize with the calling thread.

Therefore, it's not recommended to read global shader uniform values continuously in a script. If you need to read values in a script after setting them, consider creating an autoload where you store the values you need to query at the same time you're setting them as global uniforms.

Per-instance uniforms

Note

Per-instance uniforms are only available in spatial (3D) shaders.

Sometimes, you want to modify a parameter on each node using the material. As an example, in a forest full of trees, when you want each tree to have a slightly different color that is editable by hand. Without per-instance uniforms, this requires creating a unique material for each tree (each with a slightly different hue). This makes material management more complex, and also has a performance overhead due to the scene requiring more unique material instances. Vertex colors could also be used here, but they'd require creating unique copies of the mesh for each different color, which also has a performance overhead.

Per-instance uniforms are set on each GeometryInstance3D, rather than on each Material instance. Take this into account when working with meshes that have multiple materials assigned to them, or MultiMesh setups.

shader_type spatial;

// Provide a hint to edit as a color. Optionally, a default value can be provided.
// If no default value is provided, the type's default is used (e.g. opaque black for colors).
instance uniform vec4 my_color : source_color = vec4(1.0, 0.5, 0.0, 1.0);

void fragment() {
    ALBEDO = my_color.rgb;
}

After saving the shader, you can change the per-instance uniform's value using the inspector:

Setting a per-instance uniform's value in the GeometryInstance3D section of the inspector

Per-instance uniform values can also be set at run-time using set_instance_shader_parameter<class_GeometryInstance3D_method_set_instance_shader_parameter> method on a node that inherits from GeometryInstance3D:

$MeshInstance3D.set_instance_shader_parameter("my_color", Color(0.3, 0.6, 1.0))

When using per-instance uniforms, there are some restrictions you should be aware of:

• Per-instance uniforms do not support textures, only regular scalar and vector types. As a workaround, you can pass a texture array as a regular uniform, then pass the index of the texture to be drawn using a per-instance uniform.

• There is a practical maximum limit of 16 instance uniforms per shader.

• If your mesh uses multiple materials, the parameters for the first mesh material found will "win" over the subsequent ones, unless they have the same name, index and type. In this case, all parameters are affected correctly.

• If you run into the above situation, you can avoid clashes by manually specifying the index (0-15) of the instance uniform by using the instance_index hint:

instance uniform vec4 my_color : source_color, instance_index(5);

Variables intégrées

A large number of built-in variables are available, like UV, COLOR and VERTEX. What variables are available depends on the type of shader (spatial, canvas_item or particle) and the function used (vertex, fragment or light). For a list of the built-in variables that are available, please see the corresponding pages:

• Spatial shaders

• Canvas item shaders

• Particle shaders

• Sky shaders

• Fog shaders

Fonctions intégrées

Un grand nombre de fonctions intégrées sont prises en charge, conformément à GLSL ES 3.0. Lorsque la nomenclature vec_type (float), vec_int_type, vec_uint_type, vec_bool_type est utilisée, elle peut être scalaire ou vectorielle.

Fonction	Description / Return value
vec_type radians (vec_type degrees)	Convert degrees to radians.
vec_type degrees (vec_type radians)	Convert radians to degrees.
vec_type sin (vec_type x)	Sine.
vec_type cos (vec_type x)	Cosine.
vec_type tan (vec_type x)	Tangent.
vec_type asin (vec_type x)	Arcsine.
vec_type acos (vec_type x)	Arccosine.
vec_type atan (vec_type y_over_x)	Arctangent.
vec_type atan (vec_type y, vec_type x)	Arctangent.
vec_type sinh (vec_type x)	Hyperbolic sine.
vec_type cosh (vec_type x)	Hyperbolic cosine.
vec_type tanh (vec_type x)	Hyperbolic tangent.
vec_type asinh (vec_type x)	Inverse hyperbolic sine.
vec_type acosh (vec_type x)	Inverse hyperbolic cosine.
vec_type atanh (vec_type x)	Inverse hyperbolic tangent.
vec_type pow (vec_type x, vec_type y)	Power (undefined if x < 0 or if x == 0 and y <= 0).
vec_type exp (vec_type x)	Base-e exponential.
vec_type exp2 (vec_type x)	Base-2 exponential.
vec_type log (vec_type x)	Natural logarithm.
vec_type log2 (vec_type x)	Base-2 logarithm.
vec_type sqrt (vec_type x)	Square root.
vec_type inversesqrt (vec_type x)	Inverse square root.
vec_type abs (vec_type x) ivec_type abs (ivec_type x)	Absolute value (returns positive value if negative).
vec_type sign (vec_type x) ivec_type sign (ivec_type x)	Sign (returns 1.0 if positive, -1.0 if negative, 0.0 if zero).
vec_type floor (vec_type x)	Round to the integer below.
vec_type round (vec_type x)	Round to the nearest integer.
vec_type roundEven (vec_type x)	Round to the nearest even integer.
vec_type trunc (vec_type x)	Truncation.
vec_type ceil (vec_type x)	Round to the integer above.
vec_type fract (vec_type x)	Fractional (returns x - floor(x)).
vec_type mod (vec_type x, vec_type y) vec_type mod (vec_type x, float y)	Modulo (division remainder).
vec_type modf (vec_type x, out vec_type i)	Fractional of x, with i as integer part.
vec_type min (vec_type a, vec_type b)	Lowest value between a and b.
vec_type max (vec_type a, vec_type b)	Highest value between a and b.
vec_type clamp (vec_type x, vec_type min, vec_type max)	Clamp x between min and max (inclusive).
float mix (float a, float b, float c) vec_type mix (vec_type a, vec_type b, float c) vec_type mix (vec_type a, vec_type b, bvec_type c)	Linear interpolate between a and b by c.
vec_type fma (vec_type a, vec_type b, vec_type c)	Performs a fused multiply-add operation: (a * b + c) (faster than doing it manually).
vec_type step (vec_type a, vec_type b)	b[i] < a[i] ? 0.0 : 1.0.
vec_type step (float a, vec_type b)	b[i] < a ? 0.0 : 1.0.
vec_type smoothstep (vec_type a, vec_type b, vec_type c) vec_type smoothstep (float a, float b, vec_type c)	Hermite interpolate between a and b by c.
bvec_type isnan (vec_type x)	Returns true if scalar or vector component is NaN.
bvec_type isinf (vec_type x)	Returns true if scalar or vector component is INF.
ivec_type floatBitsToInt (vec_type x)	Float->Int bit copying, no conversion.
uvec_type floatBitsToUint (vec_type x)	Float->UInt bit copying, no conversion.
vec_type intBitsToFloat (ivec_type x)	Int->Float bit copying, no conversion.
vec_type uintBitsToFloat (uvec_type x)	UInt->Float bit copying, no conversion.
float length (vec_type x)	Vector length.
float distance (vec_type a, vec_type b)	Distance between vectors i.e length(a - b).
float dot (vec_type a, vec_type b)	Dot product.
vec3 cross (vec3 a, vec3 b)	Cross product.
vec_type normalize (vec_type x)	Normalize to unit length.
vec3 reflect (vec3 I, vec3 N)	Reflect.
vec3 refract (vec3 I, vec3 N, float eta)	Refract.
vec_type faceforward (vec_type N, vec_type I, vec_type Nref)	If dot(Nref, I) < 0, return N, otherwise -N.
mat_type matrixCompMult (mat_type x, mat_type y)	Matrix component multiplication.
mat_type outerProduct (vec_type column, vec_type row)	Matrix outer product.
mat_type transpose (mat_type m)	Transpose matrix.
float determinant (mat_type m)	Matrix determinant.
mat_type inverse (mat_type m)	Inverse matrix.
bvec_type lessThan (vec_type x, vec_type y)	Bool vector comparison on < int/uint/float vectors.
bvec_type greaterThan (vec_type x, vec_type y)	Bool vector comparison on > int/uint/float vectors.
bvec_type lessThanEqual (vec_type x, vec_type y)	Bool vector comparison on <= int/uint/float vectors.
bvec_type greaterThanEqual (vec_type x, vec_type y)	Bool vector comparison on >= int/uint/float vectors.
bvec_type equal (vec_type x, vec_type y)	Bool vector comparison on == int/uint/float vectors.
bvec_type nonEgaux (vec_type x, vec_type y)	Bool vector comparison on != int/uint/float vectors.
bool n'importe (bvec_type x)	true if any component is true, false otherwise.
bool all (bvec_type x)	true if all components are true, false otherwise.
bvec_type not (bvec_type x)	Invert boolean vector.
ivec2 textureSize (gsampler2D s, int lod) ivec3 textureSize (gsampler2DArray s, int lod) ivec3 textureSize (gsampler3D s, int lod) ivec2 textureSize (samplerCube s, int lod) ivec2 textureSize (samplerCubeArray s, int lod)	Get the size of a texture. The LOD defines which mipmap level is used. An LOD value of 0 will use the full resolution texture.
vec2 textureQueryLod (gsampler2D s, vec2 p) vec3 textureQueryLod (gsampler2DArray s, vec2 p) vec2 textureQueryLod (gsampler3D s, vec3 p) vec2 textureQueryLod (samplerCube s, vec3 p)	Compute the level-of-detail that would be used to sample from a texture. The x component of the resulted value is the mipmap array that would be accessed. The y component is computed level-of-detail relative to the base level (regardless of the mipmap levels of the texture).
int textureQueryLevels (gsampler2D s) int textureQueryLevels (gsampler2DArray s) int textureQueryLevels (gsampler3D s) int textureQueryLevels (samplerCube s)	Get the number of accessible mipmap levels of a texture. If the texture is unassigned to a sampler, 0 is returned.
gvec4_type texture (gsampler2D s, vec2 p [, float bias]) vec4_type texture (sampler2DArray_type s, vec3 uv [, float bias]) vec4_type texture (sampler3D_type s, vec3 uv [, float bias]) vec4 texture (samplerCube s, vec3 p [, float bias]) vec4 texture (samplerCubeArray s, vec4 p [, float bias])	Perform a texture read.
gvec4_type textureProj (gsampler2D s, vec3 p [, float bias]) gvec4_type textureProj (gsampler2D s, vec4 p [, float bias]) vec4_type textureProj (sampler3D_type s, vec4 uv [, float bias])	Perform a texture read with projection.
gvec4_type textureLod (gsampler2D s, vec2 p, float lod) gvec4_type textureLod (gsampler2DArray s, vec3 p, float lod) gvec4_type textureLod (gsampler3D s, vec3 p, float lod) vec4 textureLod (samplerCube s, vec3 p, float lod) vec4 textureLod (samplerCubeArray s, vec4 p, float lod)	Perform a texture read at custom mipmap. The LOD defines which mipmap level is used. An LOD value of 0.0 will use the full resolution texture. If the texture lacks mipmaps, all LOD values will act like 0.0.
gvec4_type textureProjLod (gsampler2D s, vec3 p, float lod) gvec4_type textureProjLod (gsampler2D s, vec4 p, float lod) gvec4_type textureProjLod (gsampler3D s, vec4 p, float lod)	Performs a texture read with projection/LOD. The LOD defines which mipmap level is used. An LOD value of 0.0 will use the full resolution texture. If the texture lacks mipmaps, all LOD values will act like 0.0.
gvec4_type textureGrad (gsampler2D s, vec2 p, vec2 dPdx, vec2 dPdy) gvec4_type textureGrad (gsampler2DArray s, vec3 p, vec2 dPdx, vec2 dPdy) gvec4_type textureGrad (gsampler3D s, vec3 p, vec2 dPdx, vec2 dPdy) vec4 textureGrad (samplerCube s, vec3 p, vec3 dPdx, vec3 dPdy) vec4 textureGrad (samplerCubeArray s, vec3 p, vec3 dPdx, vec3 dPdy)	Performs a texture read with explicit gradients.
gvec4_type textureProjGrad (gsampler2D s, vec3 p, vec2 dPdx, vec2 dPdy) gvec4_type textureProjGrad (gsampler2D s, vec4 p, vec2 dPdx, vec2 dPdy) gvec4_type textureProjGrad (gsampler3D s, vec4 p, vec3 dPdx, vec3 dPdy)	Performs a texture read with projection/LOD and with explicit gradients.
gvec4_type texelFetch (gsampler2D s, ivec2 p, int lod) gvec4_type texelFetch (gsampler2DArray s, ivec3 p, int lod) gvec4_type texelFetch (gsampler3D s, ivec3 p, int lod)	Fetches a single texel using integer coordinates. The LOD defines which mipmap level is used. An LOD value of 0 will use the full resolution texture.
gvec4_type textureGather (gsampler2D s, vec2 p [, int comps]) vec4_type texture (sampler2DArray_type s, vec3 uv [, float bias]) vec4 textureGather (samplerCube s, vec3 p [, int comps])	Gathers four texels from a texture. Use comps within range of 0..3 to define which component (x, y, z, w) is returned. If comps is not provided: 0 (or x-component) is used.
vec_type dFdx (vec_type p)	Derivative in x using local differencing. Internally, can use either dFdxCoarse or dFdxFine, but the decision for which to use is made by the GPU driver.
vec_type dFdxCoarse (vec_type p)	Calculates derivative with respect to x window coordinate using local differencing based on the value of p for the current fragment neighbour(s), and will possibly, but not necessarily, include the value for the current fragment. This function is not available on gl_compatibility profile.
vec_type dFdxFine (vec_type p)	Calculates derivative with respect to x window coordinate using local differencing based on the value of p for the current fragment and its immediate neighbour(s). This function is not available on gl_compatibility profile.
vec_type dFdy (vec_type p)	Derivative in y using local differencing. Internally, can use either dFdyCoarse or dFdyFine, but the decision for which to use is made by the GPU driver.
vec_type dFdyCoarse (vec_type p)	Calculates derivative with respect to y window coordinate using local differencing based on the value of p for the current fragment neighbour(s), and will possibly, but not necessarily, include the value for the current fragment. This function is not available on gl_compatibility profile.
vec_type dFdyFine (vec_type p)	Calculates derivative with respect to y window coordinate using local differencing based on the value of p for the current fragment and its immediate neighbour(s). This function is not available on gl_compatibility profile.
vec_type fwidth (vec_type p)	Sum of absolute derivative in x and y. This is the equivalent of using abs(dFdx(p)) + abs(dFdy(p)).
vec_type fwidthCoarse (vec_type p)	Sum of absolute derivative in x and y. This is the equivalent of using abs(dFdxCoarse(p)) + abs(dFdyCoarse(p)). This function is not available on gl_compatibility profile.
vec_type fwidthFine (vec_type p)	Sum of absolute derivative in x and y. This is the equivalent of using abs(dFdxFine(p)) + abs(dFdyFine(p)). This function is not available on gl_compatibility profile.
uint packHalf2x16 (vec2 v) vec2 unpackHalf2x16 (uint v)	Convert two 32-bit floating-point numbers into 16-bit and pack them into a 32-bit unsigned integer and vice-versa.
uint packUnorm2x16 (vec2 v) vec2 unpackUnorm2x16 (uint v)	Convert two 32-bit floating-point numbers (clamped within 0..1 range) into 16-bit and pack them into a 32-bit unsigned integer and vice-versa.
uint packSnorm2x16 (vec2 v) vec2 unpackSnorm2x16 (uint v)	Convert two 32-bit floating-point numbers (clamped within -1..1 range) into 16-bit and pack them into a 32-bit unsigned integer and vice-versa.
uint packUnorm4x8 (vec4 v) vec4 unpackUnorm4x8 (uint v)	Convert four 32-bit floating-point numbers (clamped within 0..1 range) into 8-bit and pack them into a 32-bit unsigned integer and vice-versa.
uint packSnorm4x8 (vec4 v) vec4 unpackSnorm4x8 (uint v)	Convert four 32-bit floating-point numbers (clamped within -1..1 range) into 8-bit and pack them into a 32-bit unsigned integer and vice-versa.
ivec_type bitfieldExtract (ivec_type value, int offset, int bits) uvec_type bitfieldExtract (uvec_type value, int offset, int bits)	Extracts a range of bits from an integer.
ivec_type bitfieldInsert (ivec_type base, ivec_type insert, int offset, int bits) uvec_type bitfieldInsert (uvec_type base, uvec_type insert, int offset, int bits)	Insert a range of bits into an integer.
ivec_type bitfieldReverse (ivec_type value) uvec_type bitfieldReverse (uvec_type value)	Reverse the order of bits in an integer.
ivec_type bitCount (ivec_type value) uvec_type bitCount (uvec_type value)	Counts the number of 1 bits in an integer.
ivec_type findLSB (ivec_type value) uvec_type findLSB (uvec_type value)	Find the index of the least significant bit set to 1 in an integer.
ivec_type findMSB (ivec_type value) uvec_type findMSB (uvec_type value)	Find the index of the most significant bit set to 1 in an integer.
void imulExtended (ivec_type x, ivec_type y, out ivec_type msb, out ivec_type lsb) void umulExtended (uvec_type x, uvec_type y, out uvec_type msb, out uvec_type lsb)	Multiplies two 32-bit numbers and produce a 64-bit result. x - the first number. y - the second number. msb - will contain the most significant bits. lsb - will contain the least significant bits.
uvec_type uaddCarry (uvec_type x, uvec_type y, out uvec_type carry)	Adds two unsigned integers and generates carry.
uvec_type usubBorrow (uvec_type x, uvec_type y, out uvec_type borrow)	Subtracts two unsigned integers and generates borrow.
vec_type ldexp (vec_type x, out ivec_type exp)	Assemble a floating-point number from a value and exponent. If this product is too large to be represented in the floating-point type the result is undefined.
vec_type frexp (vec_type x, out ivec_type exp)	Splits a floating-point number(x) into significand (in the range of [0.5, 1.0]) and an integral exponent. For x equals zero the significand and exponent are both zero. For x of infinity or NaN, the results are undefined.