Chapter 486: StorageBufferNode

Core Idea

This node is used in context of compute shaders and allows to define a storage buffer for data. A typical workflow is to create instances of this node with the convenience functions attributeArray() or instancedArray(), setup up a compute shader that writes into the buffers and then convert the storage buffers to attribute nodes for rendering.

Key Concepts

access : string: The access type of the texture node.
global : boolean: StorageBufferNode sets this property to true by default.
isAtomic : boolean: Whether the node is atomic or not.
isPBO : boolean: Whether the node represents a PBO or not. Only relevant for WebGL.
isStorageBufferNode : boolean (readonly): This flag can be used for type testing.
structTypeNode : StructTypeNode: The buffer struct type.

Code Examples

const positionBuffer = instancedArray( particleCount, 'vec3' ); // the storage buffer node
const computeInit = Fn( () => { // the compute shader
	const position = positionBuffer.element( instanceIndex );
	// compute position data
	position.x = 1;
	position.y = 1;
	position.z = 1;
} )().compute( particleCount );
const particleMaterial = new THREE.SpriteNodeMaterial();
particleMaterial.positionNode = positionBuffer.toAttribute();
renderer.computeAsync( computeInit );

What it demonstrates: Typical usage of StorageBufferNode.

Reference Tables

Constructor

Signature
`new StorageBufferNode( value : StorageBufferAttribute

Properties

Property	Description
`.access : string`	The access type of the texture node.
`.global : boolean`	`StorageBufferNode` sets this property to `true` by default.
`.isAtomic : boolean`	Whether the node is atomic or not.
`.isPBO : boolean`	Whether the node represents a PBO or not. Only relevant for WebGL.
`.isStorageBufferNode : boolean (readonly)`	This flag can be used for type testing.
`.structTypeNode : StructTypeNode`	The buffer struct type.

Methods

Method	Description
`.element( indexNode : IndexNode ) : StorageArrayElementNode`	Enables element access with the given index node.
`.generate( builder : NodeBuilder ) : string`	Generates the code snippet of the storage buffer node.
`.generateNodeType( builder : NodeBuilder ) : string`	This method is overwritten since the node type from the availability of storage buffers and the attribute data.
`.getAttributeData() : Object`	Returns attribute data for this storage buffer node.
`.getHash( builder : NodeBuilder ) : string`	This method is overwritten since the buffer data might be shared and thus the hash should be shared as well.
`.getInputType( builder : NodeBuilder ) : string`	Overwrites the default implementation to return a fixed value `'indirectStorageBuffer'` or `'storageBuffer'`.
`.getMemberType( builder : NodeBuilder, name : string ) : string`	Returns the type of a member of the struct.
`.getPBO() : boolean`	Returns the `isPBO` value.
`.setAccess( value : string ) : StorageBufferNode`	Defines the node access.
`.setAtomic( value : boolean ) : StorageBufferNode`	Defines whether the node is atomic or not.
`.setPBO( value : boolean ) : StorageBufferNode`	Defines whether this node is a PBO or not. Only relevant for WebGL.
`.toAtomic() : StorageBufferNode`	Convenience method for making this node atomic.
`.toReadOnly() : StorageBufferNode`	Convenience method for configuring a read-only node access.

Key Takeaways

StorageBufferNode extends: EventDispatcher → Node → InputNode → UniformNode → BufferNode
Most relevant properties: access, global, isAtomic, isPBO.
Key methods: element, generate, generateNodeType, getAttributeData.

Connects To

EventDispatcher: parent class
Node: parent class
InputNode: parent class
UniformNode: parent class
BufferNode: parent class
Source: src/nodes/accessors/StorageBufferNode.js