@openhps/core/dist/esm/three/nodes/accessors/AccessorsUtils.js

Open Hybrid Positioning System - Core component

import { bitangentView } from './Bitangent.js';
import { normalView, transformedNormalView } from './Normal.js';
import { tangentView } from './Tangent.js';
import { mat3 } from '../tsl/TSLBase.js';
import { mix } from '../math/MathNode.js';
import { anisotropy, anisotropyB, roughness } from '../core/PropertyNode.js';
import { positionViewDirection } from './Position.js';

/**
 * TSL object that represents the TBN matrix in view space.
 *
 * @tsl
 * @type {Node<mat3>}
 */
export const TBNViewMatrix = /*@__PURE__*/mat3(tangentView, bitangentView, normalView);

/**
 * TSL object that represents the parallax direction.
 *
 * @tsl
 * @type {Node<mat3>}
 */
export const parallaxDirection = /*@__PURE__*/positionViewDirection.mul(TBNViewMatrix) /*.normalize()*/;

/**
 * TSL function for computing parallax uv coordinates.
 *
 * @tsl
 * @function
 * @param {Node<vec2>} uv - A uv node.
 * @param {Node<vec2>} scale - A scale node.
 * @returns {Node<vec2>} Parallax uv coordinates.
 */
export const parallaxUV = (uv, scale) => uv.sub(parallaxDirection.mul(scale));

/**
 * TSL function for computing bent normals.
 *
 * @tsl
 * @function
 * @returns {Node<vec3>} Bent normals.
 */
export const transformedBentNormalView = /*@__PURE__*/(() => {
  // https://google.github.io/filament/Filament.md.html#lighting/imagebasedlights/anisotropy

  let bentNormal = anisotropyB.cross(positionViewDirection);
  bentNormal = bentNormal.cross(anisotropyB).normalize();
  bentNormal = mix(bentNormal, transformedNormalView, anisotropy.mul(roughness.oneMinus()).oneMinus().pow2().pow2()).normalize();
  return bentNormal;
})();