[name]

This class stores data for an attribute (such as vertex positions, face indices, normals, colors, UVs, and any custom attributes ) associated with a [page:BufferGeometry], which allows for more efficient passing of data to the GPU. See that page for details and a usage example. When working with vector-like data, the .fromBufferAttribute( attribute, index ) helper methods on [page:Vector2.fromBufferAttribute Vector2], [page:Vector3.fromBufferAttribute Vector3], [page:Vector4.fromBufferAttribute Vector4], and [page:Color.fromBufferAttribute Color] classes may be helpful.

Constructor

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

[page:TypedArray array] -- Must be a [link:https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/TypedArray TypedArray]. Used to instantiate the buffer.
This array should have itemSize * numVertices elements, where numVertices is the number of vertices in the associated [page:BufferGeometry BufferGeometry].

[page:Integer itemSize] -- the number of values of the array that should be 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.

[page:Boolean normalized] -- (optional) Applies to integer data only. 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 -32768 - +32767 to -1.0f - +1.0f. If [page:Boolean normalized] is false, the values will be converted to floats unmodified, i.e. 32767 becomes 32767.0f.

Properties

.array : TypedArray

The [page:TypedArray array] holding data stored in the buffer.

.count : Integer

Stores the [page:BufferAttribute.array array]'s length divided by the [page:BufferAttribute.itemSize itemSize].

If the buffer is storing a 3-component vector (such as a position, normal, or color), then this will count the number of such vectors stored.

.isBufferAttribute : Boolean

Read-only flag to check if a given object is of type [name].

.itemSize : Integer

The length of vectors that are being stored in the [page:BufferAttribute.array array].

.name : String

Optional name for this attribute instance. Default is an empty string.

.needsUpdate : Boolean

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

Setting this to true also increments the [page:BufferAttribute.version version].

.normalized : Boolean

Indicates how the underlying data in the buffer maps to the values in the GLSL shader code. See the constructor above for details.

.onUploadCallback : Function

A callback function that is executed after the Renderer has transferred the attribute array data to the GPU.

.updateRange : Object

Object containing:
[page:Integer offset]: Default is `0`. Position at which to start update.
[page:Integer count]: Default is `-1`, which means don't use update ranges.

This can be used to only update some components of stored vectors (for example, just the component related to color).

.usage : Usage

Defines the intended usage pattern of the data store for optimization purposes. Corresponds to the `usage` parameter of [link:https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/bufferData WebGLRenderingContext.bufferData](). Default is [page:BufferAttributeUsage StaticDrawUsage]. See usage [page:BufferAttributeUsage constants] for all possible values.

Note: After the initial use of a buffer, its usage cannot be changed. Instead, instantiate a new one and set the desired usage before the next render.

.version : Integer

A version number, incremented every time the [page:BufferAttribute.needsUpdate needsUpdate] property is set to true.

Methods

.applyMatrix3 ( [param:Matrix3 m] ) : this

Applies matrix [page:Matrix3 m] to every Vector3 element of this BufferAttribute.

.applyMatrix4 ( [param:Matrix4 m] ) : this

Applies matrix [page:Matrix4 m] to every Vector3 element of this BufferAttribute.

.applyNormalMatrix ( [param:Matrix3 m] ) : this

Applies normal matrix [page:Matrix3 m] to every Vector3 element of this BufferAttribute.

.transformDirection ( [param:Matrix4 m] ) : this

Applies matrix [page:Matrix4 m] to every Vector3 element of this BufferAttribute, interpreting the elements as a direction vectors.

.clone () : BufferAttribute

Return a copy of this bufferAttribute.

.copy ( [param:BufferAttribute bufferAttribute] ) : this

Copies another BufferAttribute to this BufferAttribute.

.copyArray ( array ) : this

Copy the array given here (which can be a normal array or TypedArray) into [page:BufferAttribute.array array].

See [link:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set TypedArray.set] for notes on requirements if copying a TypedArray.

.copyAt ( [param:Integer index1], [param:BufferAttribute bufferAttribute], [param:Integer index2] ) : this

Copy a vector from bufferAttribute[index2] to [page:BufferAttribute.array array][index1].

.getX ( [param:Integer index] ) : Number

Returns the x component of the vector at the given index.

.getY ( [param:Integer index] ) : Number

Returns the y component of the vector at the given index.

.getZ ( [param:Integer index] ) : Number

Returns the z component of the vector at the given index.

.getW ( [param:Integer index] ) : Number

Returns the w component of the vector at the given index.

.onUpload ( [param:Function callback] ) : this

Sets the value of the onUploadCallback property.

In the [example:webgl_buffergeometry WebGL / Buffergeometry] this is used to free memory after the buffer has been transferred to the GPU.

.set ( [param:Array value], [param:Integer offset] ) : this

value -- an [page:Array] or [page:TypedArray] from which to copy values.
offset -- (optional) index of the [page:BufferAttribute.array array] at which to start copying.

Calls [link:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set TypedArray.set]( [page:Array value], [page:Integer offset] ) on the [page:BufferAttribute.array array].

In particular, see that page for requirements on [page:Array value] being a [page:TypedArray].

.setUsage ( [param:Usage value] ) : this

Set [page:BufferAttribute.usage usage] to value. See usage [page:BufferAttributeUsage constants] for all possible input values.

Note: After the initial use of a buffer, its usage cannot be changed. Instead, instantiate a new one and set the desired usage before the next render.

.setX ( [param:Integer index], [param:Float x] ) : this

Sets the x component of the vector at the given index.

.setY ( [param:Integer index], [param:Float y] ) : this

Sets the y component of the vector at the given index.

.setZ ( [param:Integer index], [param:Float z] ) : this

Sets the z component of the vector at the given index.

.setW ( [param:Integer index], [param:Float w] ) : this

Sets the w component of the vector at the given index.

.setXY ( [param:Integer index], [param:Float x], [param:Float y] ) : this

Sets the x and y components of the vector at the given index.

.setXYZ ( [param:Integer index], [param:Float x], [param:Float y], [param:Float z] ) : this

Sets the x, y and z components of the vector at the given index.

.setXYZW ( [param:Integer index], [param:Float x], [param:Float y], [param:Float z], [param:Float w] ) : this

Sets the x, y, z and w components of the vector at the given index.

Source

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

BufferAttribute BufferAttribute BufferAttribute BufferAttribute

BufferAttribute BufferAttribute BufferAttribute BufferAttribute