You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

307 lines
6.0 KiB

import {
BufferGeometry,
Color,
Float32BufferAttribute,
Vector2,
Vector3
} from 'three';
/**
* Break faces with edges longer than maxEdgeLength
*/
class TessellateModifier {
constructor( maxEdgeLength = 0.1, maxIterations = 6 ) {
this.maxEdgeLength = maxEdgeLength;
this.maxIterations = maxIterations;
}
modify( geometry ) {
if ( geometry.index !== null ) {
geometry = geometry.toNonIndexed();
}
//
const maxIterations = this.maxIterations;
const maxEdgeLengthSquared = this.maxEdgeLength * this.maxEdgeLength;
const va = new Vector3();
const vb = new Vector3();
const vc = new Vector3();
const vm = new Vector3();
const vs = [ va, vb, vc, vm ];
const na = new Vector3();
const nb = new Vector3();
const nc = new Vector3();
const nm = new Vector3();
const ns = [ na, nb, nc, nm ];
const ca = new Color();
const cb = new Color();
const cc = new Color();
const cm = new Color();
const cs = [ ca, cb, cc, cm ];
const ua = new Vector2();
const ub = new Vector2();
const uc = new Vector2();
const um = new Vector2();
const us = [ ua, ub, uc, um ];
const u2a = new Vector2();
const u2b = new Vector2();
const u2c = new Vector2();
const u2m = new Vector2();
const u2s = [ u2a, u2b, u2c, u2m ];
const attributes = geometry.attributes;
const hasNormals = attributes.normal !== undefined;
const hasColors = attributes.color !== undefined;
const hasUVs = attributes.uv !== undefined;
const hasUV2s = attributes.uv2 !== undefined;
let positions = attributes.position.array;
let normals = hasNormals ? attributes.normal.array : null;
let colors = hasColors ? attributes.color.array : null;
let uvs = hasUVs ? attributes.uv.array : null;
let uv2s = hasUV2s ? attributes.uv2.array : null;
let positions2 = positions;
let normals2 = normals;
let colors2 = colors;
let uvs2 = uvs;
let uv2s2 = uv2s;
let iteration = 0;
let tessellating = true;
function addTriangle( a, b, c ) {
const v1 = vs[ a ];
const v2 = vs[ b ];
const v3 = vs[ c ];
positions2.push( v1.x, v1.y, v1.z );
positions2.push( v2.x, v2.y, v2.z );
positions2.push( v3.x, v3.y, v3.z );
if ( hasNormals ) {
const n1 = ns[ a ];
const n2 = ns[ b ];
const n3 = ns[ c ];
normals2.push( n1.x, n1.y, n1.z );
normals2.push( n2.x, n2.y, n2.z );
normals2.push( n3.x, n3.y, n3.z );
}
if ( hasColors ) {
const c1 = cs[ a ];
const c2 = cs[ b ];
const c3 = cs[ c ];
colors2.push( c1.x, c1.y, c1.z );
colors2.push( c2.x, c2.y, c2.z );
colors2.push( c3.x, c3.y, c3.z );
}
if ( hasUVs ) {
const u1 = us[ a ];
const u2 = us[ b ];
const u3 = us[ c ];
uvs2.push( u1.x, u1.y );
uvs2.push( u2.x, u2.y );
uvs2.push( u3.x, u3.y );
}
if ( hasUV2s ) {
const u21 = u2s[ a ];
const u22 = u2s[ b ];
const u23 = u2s[ c ];
uv2s2.push( u21.x, u21.y );
uv2s2.push( u22.x, u22.y );
uv2s2.push( u23.x, u23.y );
}
}
while ( tessellating && iteration < maxIterations ) {
iteration ++;
tessellating = false;
positions = positions2;
positions2 = [];
if ( hasNormals ) {
normals = normals2;
normals2 = [];
}
if ( hasColors ) {
colors = colors2;
colors2 = [];
}
if ( hasUVs ) {
uvs = uvs2;
uvs2 = [];
}
if ( hasUV2s ) {
uv2s = uv2s2;
uv2s2 = [];
}
for ( let i = 0, i2 = 0, il = positions.length; i < il; i += 9, i2 += 6 ) {
va.fromArray( positions, i + 0 );
vb.fromArray( positions, i + 3 );
vc.fromArray( positions, i + 6 );
if ( hasNormals ) {
na.fromArray( normals, i + 0 );
nb.fromArray( normals, i + 3 );
nc.fromArray( normals, i + 6 );
}
if ( hasColors ) {
ca.fromArray( colors, i + 0 );
cb.fromArray( colors, i + 3 );
cc.fromArray( colors, i + 6 );
}
if ( hasUVs ) {
ua.fromArray( uvs, i2 + 0 );
ub.fromArray( uvs, i2 + 2 );
uc.fromArray( uvs, i2 + 4 );
}
if ( hasUV2s ) {
u2a.fromArray( uv2s, i2 + 0 );
u2b.fromArray( uv2s, i2 + 2 );
u2c.fromArray( uv2s, i2 + 4 );
}
const dab = va.distanceToSquared( vb );
const dbc = vb.distanceToSquared( vc );
const dac = va.distanceToSquared( vc );
if ( dab > maxEdgeLengthSquared || dbc > maxEdgeLengthSquared || dac > maxEdgeLengthSquared ) {
tessellating = true;
if ( dab >= dbc && dab >= dac ) {
vm.lerpVectors( va, vb, 0.5 );
if ( hasNormals ) nm.lerpVectors( na, nb, 0.5 );
if ( hasColors ) cm.lerpColors( ca, cb, 0.5 );
if ( hasUVs ) um.lerpVectors( ua, ub, 0.5 );
if ( hasUV2s ) u2m.lerpVectors( u2a, u2b, 0.5 );
addTriangle( 0, 3, 2 );
addTriangle( 3, 1, 2 );
} else if ( dbc >= dab && dbc >= dac ) {
vm.lerpVectors( vb, vc, 0.5 );
if ( hasNormals ) nm.lerpVectors( nb, nc, 0.5 );
if ( hasColors ) cm.lerpColors( cb, cc, 0.5 );
if ( hasUVs ) um.lerpVectors( ub, uc, 0.5 );
if ( hasUV2s ) u2m.lerpVectors( u2b, u2c, 0.5 );
addTriangle( 0, 1, 3 );
addTriangle( 3, 2, 0 );
} else {
vm.lerpVectors( va, vc, 0.5 );
if ( hasNormals ) nm.lerpVectors( na, nc, 0.5 );
if ( hasColors ) cm.lerpColors( ca, cc, 0.5 );
if ( hasUVs ) um.lerpVectors( ua, uc, 0.5 );
if ( hasUV2s ) u2m.lerpVectors( u2a, u2c, 0.5 );
addTriangle( 0, 1, 3 );
addTriangle( 3, 1, 2 );
}
} else {
addTriangle( 0, 1, 2 );
}
}
}
const geometry2 = new BufferGeometry();
geometry2.setAttribute( 'position', new Float32BufferAttribute( positions2, 3 ) );
if ( hasNormals ) {
geometry2.setAttribute( 'normal', new Float32BufferAttribute( normals2, 3 ) );
}
if ( hasColors ) {
geometry2.setAttribute( 'color', new Float32BufferAttribute( colors2, 3 ) );
}
if ( hasUVs ) {
geometry2.setAttribute( 'uv', new Float32BufferAttribute( uvs2, 2 ) );
}
if ( hasUV2s ) {
geometry2.setAttribute( 'uv2', new Float32BufferAttribute( uv2s2, 2 ) );
}
return geometry2;
}
}
export { TessellateModifier };