@openhps/core/dist/esm/three/nodes/lighting/HemisphereLightNode.js

Open Hybrid Positioning System - Core component

import AnalyticLightNode from './AnalyticLightNode.js';
import { uniform } from '../core/UniformNode.js';
import { mix } from '../math/MathNode.js';
import { normalView } from '../accessors/Normal.js';
import { lightPosition } from '../accessors/Lights.js';
import { renderGroup } from '../core/UniformGroupNode.js';
import { Color } from '../../math/Color.js';

/**
 * Module for representing hemisphere lights as nodes.
 *
 * @augments AnalyticLightNode
 */
class HemisphereLightNode extends AnalyticLightNode {
  static get type() {
    return 'HemisphereLightNode';
  }

  /**
   * Constructs a new hemisphere light node.
   *
   * @param {?HemisphereLight} [light=null] - The hemisphere light source.
   */
  constructor(light = null) {
    super(light);

    /**
     * Uniform node representing the light's position.
     *
     * @type {UniformNode<vec3>}
     */
    this.lightPositionNode = lightPosition(light);

    /**
     * A node representing the light's direction.
     *
     * @type {Node<vec3>}
     */
    this.lightDirectionNode = this.lightPositionNode.normalize();

    /**
     * Uniform node representing the light's ground color.
     *
     * @type {UniformNode<vec3>}
     */
    this.groundColorNode = uniform(new Color()).setGroup(renderGroup);
  }

  /**
   * Overwritten to updated hemisphere light specific uniforms.
   *
   * @param {NodeFrame} frame - A reference to the current node frame.
   */
  update(frame) {
    const {
      light
    } = this;
    super.update(frame);
    this.lightPositionNode.object3d = light;
    this.groundColorNode.value.copy(light.groundColor).multiplyScalar(light.intensity);
  }
  setup(builder) {
    const {
      colorNode,
      groundColorNode,
      lightDirectionNode
    } = this;
    const dotNL = normalView.dot(lightDirectionNode);
    const hemiDiffuseWeight = dotNL.mul(0.5).add(0.5);
    const irradiance = mix(groundColorNode, colorNode, hemiDiffuseWeight);
    builder.context.irradiance.addAssign(irradiance);
  }
}
export default HemisphereLightNode;