three
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JavaScript 3D library
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JavaScript
import AnalyticLightNode from './AnalyticLightNode.js';
import { getDistanceAttenuation } from './LightUtils.js';
import { uniform } from '../core/UniformNode.js';
import { renderGroup } from '../core/UniformGroupNode.js';
import { pointShadow } from './PointShadowNode.js';
export const directPointLight = ( { color, lightVector, cutoffDistance, decayExponent } ) => {
const lightDirection = lightVector.normalize();
const lightDistance = lightVector.length();
const attenuation = getDistanceAttenuation( {
lightDistance,
cutoffDistance,
decayExponent
} );
const lightColor = color.mul( attenuation );
return { lightDirection, lightColor };
};
/**
* Module for representing point lights as nodes.
*
* @augments AnalyticLightNode
*/
class PointLightNode extends AnalyticLightNode {
static get type() {
return 'PointLightNode';
}
/**
* Constructs a new point light node.
*
* @param {?PointLight} [light=null] - The point light source.
*/
constructor( light = null ) {
super( light );
/**
* Uniform node representing the cutoff distance.
*
* @type {UniformNode<float>}
*/
this.cutoffDistanceNode = uniform( 0 ).setGroup( renderGroup );
/**
* Uniform node representing the decay exponent.
*
* @type {UniformNode<float>}
*/
this.decayExponentNode = uniform( 2 ).setGroup( renderGroup );
}
/**
* Overwritten to updated point light specific uniforms.
*
* @param {NodeFrame} frame - A reference to the current node frame.
*/
update( frame ) {
const { light } = this;
super.update( frame );
this.cutoffDistanceNode.value = light.distance;
this.decayExponentNode.value = light.decay;
}
/**
* Overwritten to setup point light specific shadow.
*
* @return {PointShadowNode}
*/
setupShadowNode() {
return pointShadow( this.light );
}
setupDirect( builder ) {
return directPointLight( {
color: this.colorNode,
lightVector: this.getLightVector( builder ),
cutoffDistance: this.cutoffDistanceNode,
decayExponent: this.decayExponentNode
} );
}
}
export default PointLightNode;