Uniforms are global GLSL variables. They are passed to shader programs.
When declaring a uniform of a ShaderMaterial, it is declared by value or by object.
uniforms: {
time: { value: 1.0 },
resolution: new Uniform(new Vector2())
};
Each uniform must have a value property. The type of the value must correspond to the type of the uniform variable in the GLSL code as specified for the primitive GLSL types in the table below. Uniform structures and arrays are also supported. GLSL arrays of primitive type must either be specified as an array of the corresponding v3d objects or as a flat array containing the data of all the objects. In other words; GLSL primitives in arrays must not be represented by arrays. This rule does not apply transitively. An array of vec2 arrays, each with a length of five vectors, must be an array of arrays, of either five Vector2 objects or ten numbers.
GLSL type | JavaScript type |
---|---|
int | Number |
uint (WebGL 2) | Number |
float | Number |
bool | Boolean |
bool | Number |
vec2 | v3d.Vector2 |
vec2 | Float32Array (*) |
vec2 | Array (*) |
vec3 | v3d.Vector3 |
vec3 | v3d.Color |
vec3 | Float32Array (*) |
vec3 | Array (*) |
vec4 | v3d.Vector4 |
vec4 | v3d.Quaternion |
vec4 | Float32Array (*) |
vec4 | Array (*) |
mat2 | Float32Array (*) |
mat2 | Array (*) |
mat3 | v3d.Matrix3 |
mat3 | Float32Array (*) |
mat3 | Array (*) |
mat4 | v3d.Matrix4 |
mat4 | Float32Array (*) |
mat4 | Array (*) |
ivec2, bvec2 | Float32Array (*) |
ivec2, bvec2 | Array (*) |
ivec3, bvec3 | Int32Array (*) |
ivec3, bvec3 | Array (*) |
ivec4, bvec4 | Int32Array (*) |
ivec4, bvec4 | Array (*) |
sampler2D | v3d.Texture |
samplerCube | v3d.CubeTexture |
(*) Same for an (innermost) array (dimension) of the same GLSL type, containing the components of all vectors or matrices in the array.
Sometimes you want to organize uniforms as structs in your shader code. The following style must be used so Verge3D is able to process structured uniform data.
uniforms = {
data: {
value: {
position: new Vector3(),
direction: new Vector3(0, 0, 1)
}
}
};
This definition can be mapped on the following GLSL code:
struct Data {
vec3 position;
vec3 direction;
};
uniform Data data;
It's also possible to manage structs in arrays. The syntax for this use case looks like so:
const entry1 = {
position: new Vector3(),
direction: new Vector3(0, 0, 1)
};
const entry2 = {
position: new Vector3(1, 1, 1),
direction: new Vector3(0, 1, 0)
};
uniforms = {
data: {
value: [entry1, entry2]
}
};
This definition can be mapped on the following GLSL code:
struct Data {
vec3 position;
vec3 direction;
};
uniform Data data[2];
value -- An object containing the value to set up the uniform. It's type must be one of the Uniform Types described above.
Current value of the uniform.
Returns a clone of this uniform.
If the uniform's value property is an Object with a clone() method, this is used, otherwise the value is copied by assignment.
Array values are shared between cloned Uniforms.
For more info on how to obtain the source code of this module see this page.