@openhps/core/dist/esm/three/nodes/functions/PhongLightingModel.js

Open Hybrid Positioning System - Core component

import BasicLightingModel from './BasicLightingModel.js';
import F_Schlick from './BSDF/F_Schlick.js';
import BRDF_Lambert from './BSDF/BRDF_Lambert.js';
import { diffuseColor, shininess, specularColor } from '../core/PropertyNode.js';
import { transformedNormalView } from '../accessors/Normal.js';
import { materialSpecularStrength } from '../accessors/MaterialNode.js';
import { positionViewDirection } from '../accessors/Position.js';
import { Fn, float } from '../tsl/TSLBase.js';
const G_BlinnPhong_Implicit = () => float(0.25);
const D_BlinnPhong = /*@__PURE__*/Fn(({
  dotNH
}) => {
  return shininess.mul(float(0.5)).add(1.0).mul(float(1 / Math.PI)).mul(dotNH.pow(shininess));
});
const BRDF_BlinnPhong = /*@__PURE__*/Fn(({
  lightDirection
}) => {
  const halfDir = lightDirection.add(positionViewDirection).normalize();
  const dotNH = transformedNormalView.dot(halfDir).clamp();
  const dotVH = positionViewDirection.dot(halfDir).clamp();
  const F = F_Schlick({
    f0: specularColor,
    f90: 1.0,
    dotVH
  });
  const G = G_BlinnPhong_Implicit();
  const D = D_BlinnPhong({
    dotNH
  });
  return F.mul(G).mul(D);
});

/**
 * Represents the lighting model for a phong material. Used in {@link MeshPhongNodeMaterial}.
 *
 * @augments BasicLightingModel
 */
class PhongLightingModel extends BasicLightingModel {
  /**
   * Constructs a new phong lighting model.
   *
   * @param {boolean} [specular=true] - Whether specular is supported or not.
   */
  constructor(specular = true) {
    super();

    /**
     * Whether specular is supported or not. Set this to `false` if you are
     * looking for a Lambert-like material meaning a material for non-shiny
     * surfaces, without specular highlights.
     *
     * @type {boolean}
     * @default true
     */
    this.specular = specular;
  }

  /**
   * Implements the direct lighting. The specular portion is optional an can be controlled
   * with the {@link PhongLightingModel#specular} flag.
   *
   * @param {Object} lightData - The light data.
   */
  direct({
    lightDirection,
    lightColor,
    reflectedLight
  }) {
    const dotNL = transformedNormalView.dot(lightDirection).clamp();
    const irradiance = dotNL.mul(lightColor);
    reflectedLight.directDiffuse.addAssign(irradiance.mul(BRDF_Lambert({
      diffuseColor: diffuseColor.rgb
    })));
    if (this.specular === true) {
      reflectedLight.directSpecular.addAssign(irradiance.mul(BRDF_BlinnPhong({
        lightDirection
      })).mul(materialSpecularStrength));
    }
  }

  /**
   * Implements the indirect lighting.
   *
   * @param {NodeBuilder} builder - The current node builder.
   */
  indirect(builder) {
    const {
      ambientOcclusion,
      irradiance,
      reflectedLight
    } = builder.context;
    reflectedLight.indirectDiffuse.addAssign(irradiance.mul(BRDF_Lambert({
      diffuseColor
    })));
    reflectedLight.indirectDiffuse.mulAssign(ambientOcclusion);
  }
}
export default PhongLightingModel;