# [name]

This class stores data for an attribute associated with a [page:BufferGeometry]. See that page for details and a usage example. This class is used to store builtin attributes such as vertex position, normals, color, etc., but can also be used in your code to store custom attributes in a [page:BufferGeometry].

## Constructor

### [name]( [page:TypedArray array], [page:Integer itemSize], [page:Boolean normalized] )

Instantiates this attribute with data from the associated buffer. itemSize gives the number of values of the array that should be associated with a particular vertex. normalized indicates how the underlying data in the buffer maps to the values in the GLSL shader code.

## Properties

### [property:TypedArray array]

Stores the data associated with this attribute. This element should have `itemSize * numVertices` elements, where numVertices is the number of vertices in the associated [page:BufferGeometry geometry]. [page:TypedArray array] can be an instance of UInt8Array, Int8Array, UInt16Array, Int16Array, or Float32Array.

### [property:Integer itemSize]

Records how many items of the array are associated with a particular vertex. For instance, if this attribute is storing a 3-component vector (such as a position, normal, or color), then itemSize should be 3.

### [property:Integer count]

Gives the total number of elements in the array.

### [property:Boolean needsUpdate]

Flag to indicate that this attribute has changed and should be re-send to the GPU. Set this to true when you modify the value of the array.

### [property:Boolean normalized]

Indicates how the underlying data in the buffer maps to the values in the GLSL code. For instance, if [page:TypedArray array] is an instance of UInt16Array, and [page:Boolean normalized] is true, the values 0 - +65535 in the array data will be mapped to 0.0f - +1.0f in the GLSL attribute. An Int16Array (signed) would map from -32767 - +32767 to -1.0f - +1.0f. If [page:Boolean normalized] is false, the values will be converted to floats which contain the exact value, i.e. 32767 becomes 32767.0f.

### [property:Integer version]

A version number, incremented every time the needsUpdate property is set to true.

## Methods

### [method:null copyAt] ( [page:Integer index1], attribute, [page:Integer index2] )

Copies itemSize values in the array from the vertex at index2 to the vertex at index1.

### [method:null set] ( [page:Array value] )

Sets the associated array with values from the passed array.

### [method:null setX]( index, x )

Sets the value of the array at `index * itemSize` to x

### [method:null setY]( index, y )

Sets the value of the array at `index * itemSize + 1` to y

### [method:null setZ]( index, z )

Sets the value of the array at `index * itemSize + 2` to z

### [method:null setXY]( index, x, y )

Sets the value of the array at `index * itemSize` to x and sets the value of the array at `index * itemSize + 1` to y

### [method:null setXYZ]( index, x, y, z )

Sets the value of the array at `index * itemSize` to x, the value of the array at `index * itemSize + 1` to y, and the value of the array at `index * itemSize + 2` to z.

### [method:null setXYZW]( index, x, y, z, w )

Sets the value of the array at `index * itemSize` to x, the value of the array at `index * itemSize + 1` to y, the value of the array at `index * itemSize + 2` to z, and the value of the array at `index * itemSize + 3` to w.

### [method:BufferAttribute clone]()

Copies this attribute.

## Source

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