three.js/docs/pages/BufferAttribute.html.md

BufferAttribute

This class stores data for an attribute (such as vertex positions, face indices, normals, colors, UVs, and any custom attributes ) associated with a geometry, which allows for more efficient passing of data to the GPU.

When working with vector-like data, the fromBufferAttribute( attribute, index ) helper methods on vector and color class might be helpful. E.g. Vector3#fromBufferAttribute.

Constructor

new BufferAttribute( array : TypedArray, itemSize : number, normalized : boolean )

Constructs a new buffer attribute.

array

The array holding the attribute data.

itemSize

The item size.

normalized

Whether the data are normalized or not.

Default is false.

Properties

.array : TypedArray

The array holding the attribute data. It should have itemSize * numVertices elements, where numVertices is the number of vertices in the associated geometry.

.count : number (readonly)

Represents the number of items this buffer attribute stores. It is internally computed by dividing the array length by the itemSize.

.gpuType : FloatType | IntType

Configures the bound GPU type for use in shaders.

Note: this only has an effect for integer arrays and is not configurable for float arrays. For lower precision float types, use Float16BufferAttribute.

Default is FloatType.

.id : number (readonly)

The ID of the buffer attribute.

.isBufferAttribute : boolean (readonly)

This flag can be used for type testing.

Default is true.

.itemSize : number

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 the value should be 3.

.name : string

The name of the buffer attribute.

.needsUpdate : number

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.

Default is false.

.normalized : boolean

Applies to integer data only. Indicates how the underlying data in the buffer maps to the values in the GLSL code. For instance, if array is an instance of UInt16Array, and normalized is true, the values 0 - +65535 in the array data will be mapped to 0.0f - +1.0f in the GLSL attribute. If normalized is false, the values will be converted to floats unmodified, i.e. 65535 becomes 65535.0f.

.updateRanges : Array.

This can be used to only update some components of stored vectors (for example, just the component related to color). Use the addUpdateRange() function to add ranges to this array.

.usage : StaticDrawUsage | DynamicDrawUsage | StreamDrawUsage | StaticReadUsage | DynamicReadUsage | StreamReadUsage | StaticCopyUsage | DynamicCopyUsage | StreamCopyUsage

Defines the intended usage pattern of the data store for optimization purposes.

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.

Default is StaticDrawUsage.

.version : number

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

Methods

.addUpdateRange( start : number, count : number )

Adds a range of data in the data array to be updated on the GPU.

start

Position at which to start update.

count

The number of components to update.

.applyMatrix3( m : Matrix3 ) : BufferAttribute

Applies the given 3x3 matrix to the given attribute. Works with item size 2 and 3.

m

The matrix to apply.

Returns: A reference to this instance.

.applyMatrix4( m : Matrix4 ) : BufferAttribute

Applies the given 4x4 matrix to the given attribute. Only works with item size 3.

m

The matrix to apply.

Returns: A reference to this instance.

.applyNormalMatrix( m : Matrix3 ) : BufferAttribute

Applies the given 3x3 normal matrix to the given attribute. Only works with item size 3.

m

The normal matrix to apply.

Returns: A reference to this instance.

.clearUpdateRanges()

Clears the update ranges.

.clone() : BufferAttribute

Returns a new buffer attribute with copied values from this instance.

Returns: A clone of this instance.

.copy( source : BufferAttribute ) : BufferAttribute

Copies the values of the given buffer attribute to this instance.

source

The buffer attribute to copy.

Returns: A reference to this instance.

.copyArray( array : TypedArray | Array ) : BufferAttribute

Copies the given array data into this buffer attribute.

array

The array to copy.

Returns: A reference to this instance.

.copyAt( index1 : number, attribute : BufferAttribute, index2 : number ) : BufferAttribute

Copies a vector from the given buffer attribute to this one. The start and destination position in the attribute buffers are represented by the given indices.

index1

The destination index into this buffer attribute.

attribute

The buffer attribute to copy from.

index2

The source index into the given buffer attribute.

Returns: A reference to this instance.

.getComponent( index : number, component : number ) : number

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

index

The index into the buffer attribute.

component

The component index.

Returns: The returned value.

.getW( index : number ) : number

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

index

The index into the buffer attribute.

Returns: The w component.

.getX( index : number ) : number

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

index

The index into the buffer attribute.

Returns: The x component.

.getY( index : number ) : number

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

index

The index into the buffer attribute.

Returns: The y component.

.getZ( index : number ) : number

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

index

The index into the buffer attribute.

Returns: The z component.

.onUpload( callback : function ) : BufferAttribute

Sets the given callback function that is executed after the Renderer has transferred the attribute array data to the GPU. Can be used to perform clean-up operations after the upload when attribute data are not needed anymore on the CPU side.

callback

The onUpload() callback.

Returns: A reference to this instance.

.onUploadCallback()

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

.set( value : TypedArray | Array, offset : number ) : BufferAttribute

Sets the given array data in the buffer attribute.

value

The array data to set.

offset

The offset in this buffer attribute's array.

Default is 0.

Returns: A reference to this instance.

.setComponent( index : number, component : number, value : number ) : BufferAttribute

Sets the given value to the given component of the vector at the given index.

index

The index into the buffer attribute.

component

The component index.

value

The value to set.

Returns: A reference to this instance.

.setUsage( value : StaticDrawUsage | DynamicDrawUsage | StreamDrawUsage | StaticReadUsage | DynamicReadUsage | StreamReadUsage | StaticCopyUsage | DynamicCopyUsage | StreamCopyUsage ) : BufferAttribute

Sets the usage of this buffer attribute.

value

The usage to set.

Returns: A reference to this buffer attribute.

.setW( index : number, w : number ) : BufferAttribute

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

index

The index into the buffer attribute.

w

The value to set.

Returns: A reference to this instance.

.setX( index : number, x : number ) : BufferAttribute

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

index

The index into the buffer attribute.

x

The value to set.

Returns: A reference to this instance.

.setXY( index : number, x : number, y : number ) : BufferAttribute

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

index

The index into the buffer attribute.

x

The value for the x component to set.

y

The value for the y component to set.

Returns: A reference to this instance.

.setXYZ( index : number, x : number, y : number, z : number ) : BufferAttribute

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

index

The index into the buffer attribute.

x

The value for the x component to set.

y

The value for the y component to set.

z

The value for the z component to set.

Returns: A reference to this instance.

.setXYZW( index : number, x : number, y : number, z : number, w : number ) : BufferAttribute

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

index

The index into the buffer attribute.

x

The value for the x component to set.

y

The value for the y component to set.

z

The value for the z component to set.

w

The value for the w component to set.

Returns: A reference to this instance.

.setY( index : number, y : number ) : BufferAttribute

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

index

The index into the buffer attribute.

y

The value to set.

Returns: A reference to this instance.

.setZ( index : number, z : number ) : BufferAttribute

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

index

The index into the buffer attribute.

z

The value to set.

Returns: A reference to this instance.

.toJSON() : Object

Serializes the buffer attribute into JSON.

Returns: A JSON object representing the serialized buffer attribute.

.transformDirection( m : Matrix4 ) : BufferAttribute

Applies the given 4x4 matrix to the given attribute. Only works with item size 3 and with direction vectors.

m

The matrix to apply.

Returns: A reference to this instance.

Source

src/core/BufferAttribute.js