three 基础库
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import { TempNode } from '../core/TempNode.js';
import { FloatNode } from '../inputs/FloatNode.js';
import { FunctionNode } from '../core/FunctionNode.js';
import { NormalNode } from '../accessors/NormalNode.js';
import { PositionNode } from '../accessors/PositionNode.js';
class BumpMapNode extends TempNode {
constructor( value, scale ) {
super( 'v3' );
this.value = value;
this.scale = scale || new FloatNode( 1 );
this.toNormalMap = false;
}
generate( builder, output ) {
if ( builder.isShader( 'fragment' ) ) {
if ( this.toNormalMap ) {
const bumpToNormal = builder.include( BumpMapNode.Nodes.bumpToNormal );
return builder.format( bumpToNormal + '( ' + this.value.build( builder, 'sampler2D' ) + ', ' +
this.value.uv.build( builder, 'v2' ) + ', ' +
this.scale.build( builder, 'f' ) + ' )', this.getType( builder ), output );
} else {
const derivativeHeight = builder.include( BumpMapNode.Nodes.dHdxy_fwd ),
perturbNormalArb = builder.include( BumpMapNode.Nodes.perturbNormalArb );
this.normal = this.normal || new NormalNode();
this.position = this.position || new PositionNode( PositionNode.VIEW );
const derivativeHeightCode = derivativeHeight + '( ' + this.value.build( builder, 'sampler2D' ) + ', ' +
this.value.uv.build( builder, 'v2' ) + ', ' +
this.scale.build( builder, 'f' ) + ' )';
return builder.format( perturbNormalArb + '( -' + this.position.build( builder, 'v3' ) + ', ' +
this.normal.build( builder, 'v3' ) + ', ' +
derivativeHeightCode + ' )', this.getType( builder ), output );
}
} else {
console.warn( 'THREE.BumpMapNode is not compatible with ' + builder.shader + ' shader.' );
return builder.format( 'vec3( 0.0 )', this.getType( builder ), output );
}
}
copy( source ) {
super.copy( source );
this.value = source.value;
this.scale = source.scale;
return this;
}
toJSON( meta ) {
let data = this.getJSONNode( meta );
if ( ! data ) {
data = this.createJSONNode( meta );
data.value = this.value.toJSON( meta ).uuid;
data.scale = this.scale.toJSON( meta ).uuid;
}
return data;
}
}
BumpMapNode.Nodes = ( function () {
// Bump Mapping Unparametrized Surfaces on the GPU by Morten S. Mikkelsen
// http://api.unrealengine.com/attachments/Engine/Rendering/LightingAndShadows/BumpMappingWithoutTangentSpace/mm_sfgrad_bump.pdf
// Evaluate the derivative of the height w.r.t. screen-space using forward differencing (listing 2)
const dHdxy_fwd = new FunctionNode( /* glsl */`
vec2 dHdxy_fwd( sampler2D bumpMap, vec2 vUv, float bumpScale ) {
vec2 dSTdx = dFdx( vUv );
vec2 dSTdy = dFdy( vUv );
float Hll = bumpScale * texture2D( bumpMap, vUv ).x;
float dBx = bumpScale * texture2D( bumpMap, vUv + dSTdx ).x - Hll;
float dBy = bumpScale * texture2D( bumpMap, vUv + dSTdy ).x - Hll;
return vec2( dBx, dBy );
}`
, null, { derivatives: true } );
const perturbNormalArb = new FunctionNode( /* glsl */`
vec3 perturbNormalArb( vec3 surf_pos, vec3 surf_norm, vec2 dHdxy ) {
vec3 vSigmaX = vec3( dFdx( surf_pos.x ), dFdx( surf_pos.y ), dFdx( surf_pos.z ) );
vec3 vSigmaY = vec3( dFdy( surf_pos.x ), dFdy( surf_pos.y ), dFdy( surf_pos.z ) );
vec3 vN = surf_norm; // normalized
vec3 R1 = cross( vSigmaY, vN );
vec3 R2 = cross( vN, vSigmaX );
float fDet = dot( vSigmaX, R1 );
fDet *= ( float( gl_FrontFacing ) * 2.0 - 1.0 );
vec3 vGrad = sign( fDet ) * ( dHdxy.x * R1 + dHdxy.y * R2 );
return normalize( abs( fDet ) * surf_norm - vGrad );
}`
, [ dHdxy_fwd ], { derivatives: true } );
const bumpToNormal = new FunctionNode( /* glsl */`
vec3 bumpToNormal( sampler2D bumpMap, vec2 uv, float scale ) {
vec2 dSTdx = dFdx( uv );
vec2 dSTdy = dFdy( uv );
float Hll = texture2D( bumpMap, uv ).x;
float dBx = texture2D( bumpMap, uv + dSTdx ).x - Hll;
float dBy = texture2D( bumpMap, uv + dSTdy ).x - Hll;
return vec3( .5 - ( dBx * scale ), .5 - ( dBy * scale ), 1.0 );
}`
, null, { derivatives: true } );
return {
dHdxy_fwd: dHdxy_fwd,
perturbNormalArb: perturbNormalArb,
bumpToNormal: bumpToNormal
};
} )();
BumpMapNode.prototype.nodeType = 'BumpMap';
BumpMapNode.prototype.hashProperties = [ 'toNormalMap' ];
export { BumpMapNode };