Uniform

Uniforms are global GLSL variables. They are passed to shader programs.

Code Example

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())
    };

Uniform types

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.

Uniform types
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.

Structured Uniforms

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;

Structured Uniforms with Arrays

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];

Constructor

Uniform(value : Object)

value -- An object containing the value to set up the uniform. It's type must be one of the Uniform Types described above.

Properties

# .value : Object

Current value of the uniform.

Methods

# .clone () : 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.

Source

For more info on how to obtain the source code of this module see this page.

Last updated on Wed Feb 17 2021