import {
BufferAttribute,
BufferGeometry,
Color,
FileLoader,
Float32BufferAttribute,
Loader,
Vector3
} from 'three';
/**
* Description: A THREE loader for STL ASCII files, as created by Solidworks and other CAD programs.
*
* Supports both binary and ASCII encoded files, with automatic detection of type.
*
* The loader returns a non-indexed buffer geometry.
*
* Limitations:
* Binary decoding supports "Magics" color format (http://en.wikipedia.org/wiki/STL_(file_format)#Color_in_binary_STL).
* There is perhaps some question as to how valid it is to always assume little-endian-ness.
* ASCII decoding assumes file is UTF-8.
*
* Usage:
* const loader = new STLLoader();
* loader.load( './models/stl/slotted_disk.stl', function ( geometry ) {
* scene.add( new THREE.Mesh( geometry ) );
* });
*
* For binary STLs geometry might contain colors for vertices. To use it:
* // use the same code to load STL as above
* if (geometry.hasColors) {
* material = new THREE.MeshPhongMaterial({ opacity: geometry.alpha, vertexColors: true });
* } else { .... }
* const mesh = new THREE.Mesh( geometry, material );
*
* For ASCII STLs containing multiple solids, each solid is assigned to a different group.
* Groups can be used to assign a different color by defining an array of materials with the same length of
* geometry.groups and passing it to the Mesh constructor:
*
* const mesh = new THREE.Mesh( geometry, material );
*
* For example:
*
* const materials = [];
* const nGeometryGroups = geometry.groups.length;
*
* const colorMap = ...; // Some logic to index colors.
*
* for (let i = 0; i < nGeometryGroups; i++) {
*
* const material = new THREE.MeshPhongMaterial({
* color: colorMap[i],
* wireframe: false
* });
*
* }
*
* materials.push(material);
* const mesh = new THREE.Mesh(geometry, materials);
*/
class STLLoader extends Loader {
constructor( manager ) {
super( manager );
}
load( url, onLoad, onProgress, onError ) {
const scope = this;
const loader = new FileLoader( this.manager );
loader.setPath( this.path );
loader.setResponseType( 'arraybuffer' );
loader.setRequestHeader( this.requestHeader );
loader.setWithCredentials( this.withCredentials );
loader.load( url, function ( text ) {
try {
onLoad( scope.parse( text ) );
} catch ( e ) {
if ( onError ) {
onError( e );
} else {
console.error( e );
}
scope.manager.itemError( url );
}
}, onProgress, onError );
}
parse( data ) {
function isBinary( data ) {
const reader = new DataView( data );
const face_size = ( 32 / 8 * 3 ) + ( ( 32 / 8 * 3 ) * 3 ) + ( 16 / 8 );
const n_faces = reader.getUint32( 80, true );
const expect = 80 + ( 32 / 8 ) + ( n_faces * face_size );
if ( expect === reader.byteLength ) {
return true;
}
// An ASCII STL data must begin with 'solid ' as the first six bytes.
// However, ASCII STLs lacking the SPACE after the 'd' are known to be
// plentiful. So, check the first 5 bytes for 'solid'.
// Several encodings, such as UTF-8, precede the text with up to 5 bytes:
// https://en.wikipedia.org/wiki/Byte_order_mark#Byte_order_marks_by_encoding
// Search for "solid" to start anywhere after those prefixes.
// US-ASCII ordinal values for 's', 'o', 'l', 'i', 'd'
const solid = [ 115, 111, 108, 105, 100 ];
for ( let off = 0; off < 5; off ++ ) {
// If "solid" text is matched to the current offset, declare it to be an ASCII STL.
if ( matchDataViewAt( solid, reader, off ) ) return false;
}
// Couldn't find "solid" text at the beginning; it is binary STL.
return true;
}
function matchDataViewAt( query, reader, offset ) {
// Check if each byte in query matches the corresponding byte from the current offset
for ( let i = 0, il = query.length; i < il; i ++ ) {
if ( query[ i ] !== reader.getUint8( offset + i ) ) return false;
}
return true;
}
function parseBinary( data ) {
const reader = new DataView( data );
const faces = reader.getUint32( 80, true );
let r, g, b, hasColors = false, colors;
let defaultR, defaultG, defaultB, alpha;
// process STL header
// check for default color in header ("COLOR=rgba" sequence).
for ( let index = 0; index < 80 - 10; index ++ ) {
if ( ( reader.getUint32( index, false ) == 0x434F4C4F /*COLO*/ ) &&
( reader.getUint8( index + 4 ) == 0x52 /*'R'*/ ) &&
( reader.getUint8( index + 5 ) == 0x3D /*'='*/ ) ) {
hasColors = true;
colors = new Float32Array( faces * 3 * 3 );
defaultR = reader.getUint8( index + 6 ) / 255;
defaultG = reader.getUint8( index + 7 ) / 255;
defaultB = reader.getUint8( index + 8 ) / 255;
alpha = reader.getUint8( index + 9 ) / 255;
}
}
const dataOffset = 84;
const faceLength = 12 * 4 + 2;
const geometry = new BufferGeometry();
const vertices = new Float32Array( faces * 3 * 3 );
const normals = new Float32Array( faces * 3 * 3 );
const color = new Color();
for ( let face = 0; face < faces; face ++ ) {
const start = dataOffset + face * faceLength;
const normalX = reader.getFloat32( start, true );
const normalY = reader.getFloat32( start + 4, true );
const normalZ = reader.getFloat32( start + 8, true );
if ( hasColors ) {
const packedColor = reader.getUint16( start + 48, true );
if ( ( packedColor & 0x8000 ) === 0 ) {
// facet has its own unique color
r = ( packedColor & 0x1F ) / 31;
g = ( ( packedColor >> 5 ) & 0x1F ) / 31;
b = ( ( packedColor >> 10 ) & 0x1F ) / 31;
} else {
r = defaultR;
g = defaultG;
b = defaultB;
}
}
for ( let i = 1; i <= 3; i ++ ) {
const vertexstart = start + i * 12;
const componentIdx = ( face * 3 * 3 ) + ( ( i - 1 ) * 3 );
vertices[ componentIdx ] = reader.getFloat32( vertexstart, true );
vertices[ componentIdx + 1 ] = reader.getFloat32( vertexstart + 4, true );
vertices[ componentIdx + 2 ] = reader.getFloat32( vertexstart + 8, true );
normals[ componentIdx ] = normalX;
normals[ componentIdx + 1 ] = normalY;
normals[ componentIdx + 2 ] = normalZ;
if ( hasColors ) {
color.set( r, g, b ).convertSRGBToLinear();
colors[ componentIdx ] = color.r;
colors[ componentIdx + 1 ] = color.g;
colors[ componentIdx + 2 ] = color.b;
}
}
}
geometry.setAttribute( 'position', new BufferAttribute( vertices, 3 ) );
geometry.setAttribute( 'normal', new BufferAttribute( normals, 3 ) );
if ( hasColors ) {
geometry.setAttribute( 'color', new BufferAttribute( colors, 3 ) );
geometry.hasColors = true;
geometry.alpha = alpha;
}
return geometry;
}
function parseASCII( data ) {
const geometry = new BufferGeometry();
const patternSolid = /solid([\s\S]*?)endsolid/g;
const patternFace = /facet([\s\S]*?)endfacet/g;
const patternName = /solid\s(.+)/;
let faceCounter = 0;
const patternFloat = /[\s]+([+-]?(?:\d*)(?:\.\d*)?(?:[eE][+-]?\d+)?)/.source;
const patternVertex = new RegExp( 'vertex' + patternFloat + patternFloat + patternFloat, 'g' );
const patternNormal = new RegExp( 'normal' + patternFloat + patternFloat + patternFloat, 'g' );
const vertices = [];
const normals = [];
const groupNames = [];
const normal = new Vector3();
let result;
let groupCount = 0;
let startVertex = 0;
let endVertex = 0;
while ( ( result = patternSolid.exec( data ) ) !== null ) {
startVertex = endVertex;
const solid = result[ 0 ];
const name = ( result = patternName.exec( solid ) ) !== null ? result[ 1 ] : '';
groupNames.push( name );
while ( ( result = patternFace.exec( solid ) ) !== null ) {
let vertexCountPerFace = 0;
let normalCountPerFace = 0;
const text = result[ 0 ];
while ( ( result = patternNormal.exec( text ) ) !== null ) {
normal.x = parseFloat( result[ 1 ] );
normal.y = parseFloat( result[ 2 ] );
normal.z = parseFloat( result[ 3 ] );
normalCountPerFace ++;
}
while ( ( result = patternVertex.exec( text ) ) !== null ) {
vertices.push( parseFloat( result[ 1 ] ), parseFloat( result[ 2 ] ), parseFloat( result[ 3 ] ) );
normals.push( normal.x, normal.y, normal.z );
vertexCountPerFace ++;
endVertex ++;
}
// every face have to own ONE valid normal
if ( normalCountPerFace !== 1 ) {
console.error( 'THREE.STLLoader: Something isn\'t right with the normal of face number ' + faceCounter );
}
// each face have to own THREE valid vertices
if ( vertexCountPerFace !== 3 ) {
console.error( 'THREE.STLLoader: Something isn\'t right with the vertices of face number ' + faceCounter );
}
faceCounter ++;
}
const start = startVertex;
const count = endVertex - startVertex;
geometry.userData.groupNames = groupNames;
geometry.addGroup( start, count, groupCount );
groupCount ++;
}
geometry.setAttribute( 'position', new Float32BufferAttribute( vertices, 3 ) );
geometry.setAttribute( 'normal', new Float32BufferAttribute( normals, 3 ) );
return geometry;
}
function ensureString( buffer ) {
if ( typeof buffer !== 'string' ) {
return new TextDecoder().decode( buffer );
}
return buffer;
}
function ensureBinary( buffer ) {
if ( typeof buffer === 'string' ) {
const array_buffer = new Uint8Array( buffer.length );
for ( let i = 0; i < buffer.length; i ++ ) {
array_buffer[ i ] = buffer.charCodeAt( i ) & 0xff; // implicitly assumes little-endian
}
return array_buffer.buffer || array_buffer;
} else {
return buffer;
}
}
// start
const binData = ensureBinary( data );
return isBinary( binData ) ? parseBinary( binData ) : parseASCII( ensureString( data ) );
}
}
export { STLLoader };
