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@knee-cola
Forked from chandlerprall/ThreeCSG.js
Last active Jan 12, 2021
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csg.js wrapper for three.js
/*
THREE.CSG
@author Chandler Prall <chandler.prall@gmail.com> http://chandler.prallfamily.com
Wrapper for Evan Wallace's CSG library (https://github.com/evanw/csg.js/)
Provides CSG capabilities for Three.js models.
Provided under the MIT License
*/
THREE.CSG = {
toCSG: function ( three_model ) {
var i, geometry, polygons, vertices;
if ( !CSG ) {
throw 'CSG library not loaded. Please get a copy from https://github.com/evanw/csg.js';
}
if ( three_model instanceof THREE.Mesh ) {
geometry = new THREE.Geometry();
geometry.mergeMesh(three_model);
} else if ( three_model instanceof THREE.Geometry ) {
geometry = three_model;
} else {
throw 'Model type not supported.';
}
var polygons = [];
for ( i = 0; i < geometry.faces.length; i++ ) {
if ( geometry.faces[i] instanceof THREE.Face3 ) {
vertices = [
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].a])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].b])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].c]))];
polygons.push( new CSG.Polygon( vertices ) );
} else if ( geometry.faces[i] instanceof THREE.Face4 ) {
vertices = [
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].a])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].b])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].d]))];
polygons.push( new CSG.Polygon( vertices ) );
vertices = [
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].b])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].c])),
new CSG.Vertex(new CSG.Vector3D(geometry.vertices[geometry.faces[i].d]))];
polygons.push( new CSG.Polygon( vertices ) );
} else {
throw 'Model contains unsupported face.';
}
}
return CSG.fromPolygons( polygons );
},
fromCSG: function( csg_model ) {
var i, j, vertices, face,
three_geometry = new THREE.Geometry( ),
polygons = csg_model.toPolygons( );
if ( !CSG ) {
throw 'CSG library not loaded. Please get a copy from https://github.com/evanw/csg.js';
}
for ( i = 0; i < polygons.length; i++ ) {
// Vertices
vertices = [];
for ( j = 0; j < polygons[i].vertices.length; j++ ) {
vertices.push( this.getGeometryVertice( three_geometry, polygons[i].vertices[j].pos ) );
}
if ( vertices[0] === vertices[vertices.length - 1] ) {
vertices.pop( );
}
for (var j = 2; j < vertices.length; j++) {
face = new THREE.Face3( vertices[0], vertices[j-1], vertices[j], new THREE.Vector3( ).copy( polygons[i].plane.normal ) );
three_geometry.faces.push( face );
}
}
three_geometry.computeBoundingBox();
return three_geometry;
},
getGeometryVertice: function getGeometryVertice ( geometry, vertice_position ) {
//var i;
//for ( i = 0; i < geometry.vertices.length; i++ ) {
// if ( geometry.vertices[i].position.x === vertice_position.x
// && geometry.vertices[i].position.y === vertice_position.y
// && geometry.vertices[i].position.z === vertice_position.z ) {
// // Vertice already exists
// return i;
// }
//};
geometry.vertices.push(new THREE.Vector3( vertice_position.x, vertice_position.y, vertice_position.z ) );
return geometry.vertices.length - 1;
},
subtractGeometry: function(targetGeometry, hullGeometry) {
var result = THREE.CSG.fromCSG(THREE.CSG.toCSG(targetGeometry).subtract(THREE.CSG.toCSG(hullGeometry)));
result.computeVertexNormals();
return(result);
},
intersectGeometry: function(targetGeometry, hullGeometry) {
var result = THREE.CSG.fromCSG(THREE.CSG.toCSG(targetGeometry).intersect(THREE.CSG.toCSG(hullGeometry)));
result.computeVertexNormals();
return(result);
},
removeInnerFaces: function(geometry) {
let vertices = geometry.vertices;
let selectedVertices = [];
// mapping Vertices which are located at the sphere center
for(let i=vertices.length-1; i>=0; i--) {
var oneVertice = vertices[i];
var r = oneVertice.y*oneVertice.y + oneVertice.x*oneVertice.x + oneVertice.z*oneVertice.z;
if(r < 1) {
selectedVertices.push(i);
}
}
// removing Faces which use the mapped Vertices (located at the pyramid point)
// + mapping all the remaining Vertices used by the removed Face
// > this info will be used to remove Paces which touch the sphere surface
let faces = geometry.faces;
let subSelectedV = [];
for(let i=faces.length-1; i>=0; i--) {
for(let j=selectedVertices.length; j>=0; j--) {
let matchFound = false;
switch(selectedVertices[j]) {
case faces[i].a:
subSelectedV.push(faces[i].b);
subSelectedV.push(faces[i].c);
matchFound = true;
break;
case faces[i].b:
subSelectedV.push(faces[i].a);
subSelectedV.push(faces[i].c);
matchFound = true;
break;
case faces[i].c:
subSelectedV.push(faces[i].a);
subSelectedV.push(faces[i].b);
matchFound = true;
break;
}
if(matchFound) {
faces.splice(i, 1);
break;
}
}
}
// removing all the Faces which touch the surface of the sphere
for(let i=faces.length-1; i>=0; i--) {
for(let j=subSelectedV.length; j>=0; j--) {
let matchFound = false;
switch(subSelectedV[j]) {
case faces[i].a:
case faces[i].b:
case faces[i].c:
matchFound = true;
break;
}
if(matchFound) {
faces.splice(i, 1);
break;
}
}
} // for(let i=faces.length-1; i>=0; i--) {...}
return(geometry);
} // removeInnerFaces: function(geometry) {...}
};
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