three
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JavaScript 3D library
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JavaScript
import TempNode from '../core/TempNode.js';
import { add } from '../math/OperatorNode.js';
import { normalView, transformNormalToView } from '../accessors/Normal.js';
import { positionView } from '../accessors/Position.js';
import { TBNViewMatrix } from '../accessors/AccessorsUtils.js';
import { uv } from '../accessors/UV.js';
import { faceDirection } from './FrontFacingNode.js';
import { Fn, nodeProxy, vec3 } from '../tsl/TSLBase.js';
import { TangentSpaceNormalMap, ObjectSpaceNormalMap } from '../../constants.js';
// Normal Mapping Without Precomputed Tangents
// http://www.thetenthplanet.de/archives/1180
const perturbNormal2Arb = /*@__PURE__*/ Fn( ( inputs ) => {
const { eye_pos, surf_norm, mapN, uv } = inputs;
const q0 = eye_pos.dFdx();
const q1 = eye_pos.dFdy();
const st0 = uv.dFdx();
const st1 = uv.dFdy();
const N = surf_norm; // normalized
const q1perp = q1.cross( N );
const q0perp = N.cross( q0 );
const T = q1perp.mul( st0.x ).add( q0perp.mul( st1.x ) );
const B = q1perp.mul( st0.y ).add( q0perp.mul( st1.y ) );
const det = T.dot( T ).max( B.dot( B ) );
const scale = faceDirection.mul( det.inverseSqrt() );
return add( T.mul( mapN.x, scale ), B.mul( mapN.y, scale ), N.mul( mapN.z ) ).normalize();
} );
class NormalMapNode extends TempNode {
static get type() {
return 'NormalMapNode';
}
constructor( node, scaleNode = null ) {
super( 'vec3' );
this.node = node;
this.scaleNode = scaleNode;
this.normalMapType = TangentSpaceNormalMap;
}
setup( builder ) {
const { normalMapType, scaleNode } = this;
let normalMap = this.node.mul( 2.0 ).sub( 1.0 );
if ( scaleNode !== null ) {
normalMap = vec3( normalMap.xy.mul( scaleNode ), normalMap.z );
}
let outputNode = null;
if ( normalMapType === ObjectSpaceNormalMap ) {
outputNode = transformNormalToView( normalMap );
} else if ( normalMapType === TangentSpaceNormalMap ) {
const tangent = builder.hasGeometryAttribute( 'tangent' );
if ( tangent === true ) {
outputNode = TBNViewMatrix.mul( normalMap ).normalize();
} else {
outputNode = perturbNormal2Arb( {
eye_pos: positionView,
surf_norm: normalView,
mapN: normalMap,
uv: uv()
} );
}
}
return outputNode;
}
}
export default NormalMapNode;
export const normalMap = /*@__PURE__*/ nodeProxy( NormalMapNode );