[name]

Uniforms 是 GLSL 着色器中的全局变量。

代码示例

When declaring a uniform of a [page:ShaderMaterial], it is declared by value or by object.


		uniforms: {
			time: { value: 1.0 },
			resolution: new Uniform( new Vector2() )
		};

Uniform 种类

每个 Uniform 必须包括一个 *value* 属性。value 的类型必须和下表中 GLSL 的基本类型相对应。同样，Uniform 的结构体和队列也是支持的。 GLSL基本类型队列必须要么被显示声明为一个 THREE 对象的队列，要么被声明为一个包含所有对象数据的队列。这就是说，队列中的 GLSL 基础类型不能再是一个队列。举例，一个有 5 个 *vec2* 元素的队列，必须是一个包含 5 个 [page:Vector2] 的队列数组，或包含 10 个 *number* 的队列。

Uniform 类型
GLSL 类型	JavaScript 类型
int	[page:Number]
uint (WebGL 2)	[page:Number]
float	[page:Number]
bool	[page:Boolean]
bool	[page:Number]
vec2	[page:Vector2 THREE.Vector2]
vec2	[page:Float32Array Float32Array] (*)
vec2	[page:Array Array] (*)
vec3	[page:Vector3 THREE.Vector3]
vec3	[page:Color THREE.Color]
vec3	[page:Float32Array Float32Array] (*)
vec3	[page:Array Array] (*)
vec4	[page:Vector4 THREE.Vector4]
vec4	[page:Quaternion THREE.Quaternion]
vec4	[page:Float32Array Float32Array] (*)
vec4	[page:Array Array] (*)
mat2	[page:Float32Array Float32Array] (*)
mat2	[page:Array Array] (*)
mat3	[page:Matrix3 THREE.Matrix3]
mat3	[page:Float32Array Float32Array] (*)
mat3	[page:Array Array] (*)
mat4	[page:Matrix4 THREE.Matrix4]
mat4	[page:Float32Array Float32Array] (*)
mat4	[page:Array Array] (*)
ivec2, bvec2	[page:Float32Array Float32Array] (*)
ivec2, bvec2	[page:Array Array] (*)
ivec3, bvec3	[page:Int32Array Int32Array] (*)
ivec3, bvec3	[page:Array Array] (*)
ivec4, bvec4	[page:Int32Array Int32Array] (*)
ivec4, bvec4	[page:Array Array] (*)
sampler2D	[page:Texture THREE.Texture]
samplerCube	[page:CubeTexture THREE.CubeTexture]

(*) 与最内层队列中 GSLS 的类型保持一致。包含队列中所有矢量的元素或矩阵中的元素。

Structured Uniforms

Sometimes you want to organize uniforms as *structs* in your shader code. The following style must be used so *three.js* 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 ];

构造函数

[name]( [param:Object value] )

value -- 包含需要设置 Uniform 数据的对象。数据类型必须是上述类型中的一种。

属性

[property:Object value]

当前 uniform 的值。

方法

[method:Uniform clone]()

返回该 Uniform 的克隆。
如果 Uniform 的 value 属性是一个带 clone() 方法的 [page:Object]，则克隆该对象时，value 的 clone() 方法也会被调用，否则克隆时只会使用赋值语句。队列中的值会在该 Uniform 和被克隆对象间共享。

源代码

[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]