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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, offset, rotation ) {
var i, geometry, offset, polygons, vertices, rotation_matrix;
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 = three_model.geometry;
offset = offset || three_model.position;
rotation = rotation || three_model.rotation;
} else if ( three_model instanceof THREE.Geometry ) {
geometry = three_model;
offset = offset || new THREE.Vector3( 0, 0, 0 );
rotation = rotation || new THREE.Vector3( 0, 0, 0 );
} else {
throw 'Model type not supported.';
}
rotation_matrix = new THREE.Matrix4( ).setRotationFromEuler( rotation );
var polygons = [];
for ( i = 0; i < geometry.faces.length; i++ ) {
if ( geometry.faces[i] instanceof THREE.Face3 ) {
vertices = [];
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].a].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].b].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].c].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
polygons.push( new CSG.Polygon( vertices ) );
} else if ( geometry.faces[i] instanceof THREE.Face4 ) {
vertices = [];
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].a].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].b].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].d].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
polygons.push( new CSG.Polygon( vertices ) );
vertices = [];
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].b].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].c].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
vertices.push( new CSG.Vertex( rotation_matrix.multiplyVector3( geometry.vertices[geometry.faces[i].d].position.clone( ).addSelf( offset ) ), [ geometry.faces[i].normal.x, geometry.faces[i].normal.y, geometry.faces[i].normal.z ] ) );
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.faceVertexUvs[0].push( new THREE.UV( ) );
}
}
three_geometry.computeBoundingBox();
return three_geometry;
},
getGeometryVertice: function ( 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.Vertex( new THREE.Vector3( vertice_position.x, vertice_position.y, vertice_position.z ) ) );
return geometry.vertices.length - 1;
}
};
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