three
Version:
JavaScript 3D library
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JavaScript
import { Vector2, TempNode } from 'three/webgpu';
import {
nodeObject,
Fn,
uniform,
convertToTexture,
float,
vec4,
uv,
NodeUpdateType,
} from 'three/tsl';
/**
* Post processing node for applying chromatic aberration effect.
* This effect simulates the color fringing that occurs in real camera lenses
* by separating and offsetting the red, green, and blue channels.
*
* @augments TempNode
* @three_import import { chromaticAberration } from 'three/addons/tsl/display/ChromaticAberrationNode.js';
*/
class ChromaticAberrationNode extends TempNode {
static get type() {
return 'ChromaticAberrationNode';
}
/**
* Constructs a new chromatic aberration node.
*
* @param {TextureNode} textureNode - The texture node that represents the input of the effect.
* @param {Node} strengthNode - The strength of the chromatic aberration effect as a node.
* @param {Node} centerNode - The center point of the effect as a node.
* @param {Node} scaleNode - The scale factor for stepped scaling from center as a node.
*/
constructor( textureNode, strengthNode, centerNode, scaleNode ) {
super( 'vec4' );
/**
* The texture node that represents the input of the effect.
*
* @type {texture}
*/
this.textureNode = textureNode;
/**
* The `updateBeforeType` is set to `NodeUpdateType.FRAME` since the node updates
* its internal uniforms once per frame in `updateBefore()`.
*
* @type {string}
* @default 'frame'
*/
this.updateBeforeType = NodeUpdateType.FRAME;
/**
* A node holding the strength of the effect.
*
* @type {Node}
*/
this.strengthNode = strengthNode;
/**
* A node holding the center point of the effect.
*
* @type {Node}
*/
this.centerNode = centerNode;
/**
* A node holding the scale factor for stepped scaling.
*
* @type {Node}
*/
this.scaleNode = scaleNode;
/**
* A uniform node holding the inverse resolution value.
*
* @private
* @type {UniformNode<vec2>}
*/
this._invSize = uniform( new Vector2() );
}
/**
* This method is used to update the effect's uniforms once per frame.
*
* @param {NodeFrame} frame - The current node frame.
*/
updateBefore( /* frame */ ) {
const map = this.textureNode.value;
this._invSize.value.set( 1 / map.image.width, 1 / map.image.height );
}
/**
* This method is used to setup the effect's TSL code.
*
* @param {NodeBuilder} builder - The current node builder.
* @return {ShaderCallNodeInternal}
*/
setup( /* builder */ ) {
const textureNode = this.textureNode;
const uvNode = textureNode.uvNode || uv();
const ApplyChromaticAberration = Fn( ( [ uv, strength, center, scale ] ) => {
// Calculate distance from center
const offset = uv.sub( center );
const distance = offset.length();
// Create stepped scaling zones based on distance
// Each channel gets different scaling steps
const redScale = float( 1.0 ).add( scale.mul( 0.02 ).mul( strength ) ); // Red channel scaled outward
const greenScale = float( 1.0 ); // Green stays at original scale
const blueScale = float( 1.0 ).sub( scale.mul( 0.02 ).mul( strength ) ); // Blue channel scaled inward
// Create radial distortion based on distance from center
const aberrationStrength = strength.mul( distance );
// Calculate scaled UV coordinates for each channel
const redUV = center.add( offset.mul( redScale ) );
const greenUV = center.add( offset.mul( greenScale ) );
const blueUV = center.add( offset.mul( blueScale ) );
// Apply additional chromatic offset based on aberration strength
const rOffset = offset.mul( aberrationStrength ).mul( float( 0.01 ) );
const gOffset = offset.mul( aberrationStrength ).mul( float( 0.0 ) );
const bOffset = offset.mul( aberrationStrength ).mul( float( - 0.01 ) );
// Final UV coordinates combining scale and chromatic aberration
const finalRedUV = redUV.add( rOffset );
const finalGreenUV = greenUV.add( gOffset );
const finalBlueUV = blueUV.add( bOffset );
// Sample texture for each channel
const r = textureNode.sample( finalRedUV ).r;
const g = textureNode.sample( finalGreenUV ).g;
const b = textureNode.sample( finalBlueUV ).b;
// Get original alpha
const a = textureNode.sample( uv ).a;
return vec4( r, g, b, a );
} ).setLayout( {
name: 'ChromaticAberrationShader',
type: 'vec4',
inputs: [
{ name: 'uv', type: 'vec2' },
{ name: 'strength', type: 'float' },
{ name: 'center', type: 'vec2' },
{ name: 'scale', type: 'float' },
{ name: 'invSize', type: 'vec2' }
]
} );
const chromaticAberrationFn = Fn( () => {
return ApplyChromaticAberration(
uvNode,
this.strengthNode,
this.centerNode,
this.scaleNode,
this._invSize
);
} );
const outputNode = chromaticAberrationFn();
return outputNode;
}
}
export default ChromaticAberrationNode;
/**
* TSL function for creating a chromatic aberration node for post processing.
*
* @tsl
* @function
* @param {Node<vec4>} node - The node that represents the input of the effect.
* @param {Node|number} [strength=1.0] - The strength of the chromatic aberration effect as a node or value.
* @param {Node|Vector2} [center=null] - The center point of the effect as a node or value. If null, uses screen center (0.5, 0.5).
* @param {Node|number} [scale=1.1] - The scale factor for stepped scaling from center as a node or value.
* @returns {ChromaticAberrationNode}
*/
export const chromaticAberration = ( node, strength = 1.0, center = null, scale = 1.1 ) => {
return nodeObject(
new ChromaticAberrationNode(
convertToTexture( node ),
nodeObject( strength ),
nodeObject( center ),
nodeObject( scale )
)
);
};