three.js/examples/jsm/objects/MarchingCubes.js

import {
	BufferAttribute,
	BufferGeometry,
	Color,
	ImmediateRenderObject,
	NoColors
} from "../../../build/three.module.js";
/**
 * Port of http://webglsamples.org/blob/blob.html
 */

var MarchingCubes = function ( resolution, material, enableUvs, enableColors ) {

	ImmediateRenderObject.call( this, material );

	var scope = this;

	// temp buffers used in polygonize

	var vlist = new Float32Array( 12 * 3 );
	var nlist = new Float32Array( 12 * 3 );
	var clist = new Float32Array( 12 * 3 );

	this.enableUvs = enableUvs !== undefined ? enableUvs : false;
	this.enableColors = enableColors !== undefined ? enableColors : false;

	// functions have to be object properties
	// prototype functions kill performance
	// (tested and it was 4x slower !!!)

	this.init = function ( resolution ) {

		this.resolution = resolution;

		// parameters

		this.isolation = 80.0;

		// size of field, 32 is pushing it in Javascript :)

		this.size = resolution;
		this.size2 = this.size * this.size;
		this.size3 = this.size2 * this.size;
		this.halfsize = this.size / 2.0;

		// deltas

		this.delta = 2.0 / this.size;
		this.yd = this.size;
		this.zd = this.size2;

		this.field = new Float32Array( this.size3 );
		this.normal_cache = new Float32Array( this.size3 * 3 );
		this.palette = new Float32Array( this.size3 * 3 );

		// immediate render mode simulator

		this.maxCount = 4096; // TODO: find the fastest size for this buffer
		this.count = 0;

		this.hasPositions = false;
		this.hasNormals = false;
		this.hasColors = false;
		this.hasUvs = false;

		this.positionArray = new Float32Array( this.maxCount * 3 );
		this.normalArray = new Float32Array( this.maxCount * 3 );

		if ( this.enableUvs ) {

			this.uvArray = new Float32Array( this.maxCount * 2 );

		}

		if ( this.enableColors ) {

			this.colorArray = new Float32Array( this.maxCount * 3 );

		}

	};

	///////////////////////
	// Polygonization
	///////////////////////

	function lerp( a, b, t ) {

		return a + ( b - a ) * t;

	}

	function VIntX( q, offset, isol, x, y, z, valp1, valp2, c_offset1, c_offset2 ) {

		var mu = ( isol - valp1 ) / ( valp2 - valp1 ),
			nc = scope.normal_cache;

		vlist[ offset + 0 ] = x + mu * scope.delta;
		vlist[ offset + 1 ] = y;
		vlist[ offset + 2 ] = z;

		nlist[ offset + 0 ] = lerp( nc[ q + 0 ], nc[ q + 3 ], mu );
		nlist[ offset + 1 ] = lerp( nc[ q + 1 ], nc[ q + 4 ], mu );
		nlist[ offset + 2 ] = lerp( nc[ q + 2 ], nc[ q + 5 ], mu );

		clist[ offset + 0 ] = lerp( scope.palette[ c_offset1 * 3 + 0 ], scope.palette[ c_offset2 * 3 + 0 ], mu );
		clist[ offset + 1 ] = lerp( scope.palette[ c_offset1 * 3 + 1 ], scope.palette[ c_offset2 * 3 + 1 ], mu );
		clist[ offset + 2 ] = lerp( scope.palette[ c_offset1 * 3 + 2 ], scope.palette[ c_offset2 * 3 + 2 ], mu );

	}

	function VIntY( q, offset, isol, x, y, z, valp1, valp2, c_offset1, c_offset2 ) {

		var mu = ( isol - valp1 ) / ( valp2 - valp1 ),
			nc = scope.normal_cache;

		vlist[ offset + 0 ] = x;
		vlist[ offset + 1 ] = y + mu * scope.delta;
		vlist[ offset + 2 ] = z;

		var q2 = q + scope.yd * 3;

		nlist[ offset + 0 ] = lerp( nc[ q + 0 ], nc[ q2 + 0 ], mu );
		nlist[ offset + 1 ] = lerp( nc[ q + 1 ], nc[ q2 + 1 ], mu );
		nlist[ offset + 2 ] = lerp( nc[ q + 2 ], nc[ q2 + 2 ], mu );

		clist[ offset + 0 ] = lerp( scope.palette[ c_offset1 * 3 + 0 ], scope.palette[ c_offset2 * 3 + 0 ], mu );
		clist[ offset + 1 ] = lerp( scope.palette[ c_offset1 * 3 + 1 ], scope.palette[ c_offset2 * 3 + 1 ], mu );
		clist[ offset + 2 ] = lerp( scope.palette[ c_offset1 * 3 + 2 ], scope.palette[ c_offset2 * 3 + 2 ], mu );

	}

	function VIntZ( q, offset, isol, x, y, z, valp1, valp2, c_offset1, c_offset2 ) {

		var mu = ( isol - valp1 ) / ( valp2 - valp1 ),
			nc = scope.normal_cache;

		vlist[ offset + 0 ] = x;
		vlist[ offset + 1 ] = y;
		vlist[ offset + 2 ] = z + mu * scope.delta;

		var q2 = q + scope.zd * 3;

		nlist[ offset + 0 ] = lerp( nc[ q + 0 ], nc[ q2 + 0 ], mu );
		nlist[ offset + 1 ] = lerp( nc[ q + 1 ], nc[ q2 + 1 ], mu );
		nlist[ offset + 2 ] = lerp( nc[ q + 2 ], nc[ q2 + 2 ], mu );

		clist[ offset + 0 ] = lerp( scope.palette[ c_offset1 * 3 + 0 ], scope.palette[ c_offset2 * 3 + 0 ], mu );
		clist[ offset + 1 ] = lerp( scope.palette[ c_offset1 * 3 + 1 ], scope.palette[ c_offset2 * 3 + 1 ], mu );
		clist[ offset + 2 ] = lerp( scope.palette[ c_offset1 * 3 + 2 ], scope.palette[ c_offset2 * 3 + 2 ], mu );

	}

	function compNorm( q ) {

		var q3 = q * 3;

		if ( scope.normal_cache[ q3 ] === 0.0 ) {

			scope.normal_cache[ q3 + 0 ] = scope.field[ q - 1 ] - scope.field[ q + 1 ];
			scope.normal_cache[ q3 + 1 ] =
				scope.field[ q - scope.yd ] - scope.field[ q + scope.yd ];
			scope.normal_cache[ q3 + 2 ] =
				scope.field[ q - scope.zd ] - scope.field[ q + scope.zd ];

		}

	}

	// Returns total number of triangles. Fills triangles.
	// (this is where most of time is spent - it's inner work of O(n3) loop )

	function polygonize( fx, fy, fz, q, isol, renderCallback ) {

		// cache indices
		var q1 = q + 1,
			qy = q + scope.yd,
			qz = q + scope.zd,
			q1y = q1 + scope.yd,
			q1z = q1 + scope.zd,
			qyz = q + scope.yd + scope.zd,
			q1yz = q1 + scope.yd + scope.zd;

		var cubeindex = 0,
			field0 = scope.field[ q ],
			field1 = scope.field[ q1 ],
			field2 = scope.field[ qy ],
			field3 = scope.field[ q1y ],
			field4 = scope.field[ qz ],
			field5 = scope.field[ q1z ],
			field6 = scope.field[ qyz ],
			field7 = scope.field[ q1yz ];

		if ( field0 < isol ) cubeindex |= 1;
		if ( field1 < isol ) cubeindex |= 2;
		if ( field2 < isol ) cubeindex |= 8;
		if ( field3 < isol ) cubeindex |= 4;
		if ( field4 < isol ) cubeindex |= 16;
		if ( field5 < isol ) cubeindex |= 32;
		if ( field6 < isol ) cubeindex |= 128;
		if ( field7 < isol ) cubeindex |= 64;

		// if cube is entirely in/out of the surface - bail, nothing to draw

		var bits = edgeTable[ cubeindex ];
		if ( bits === 0 ) return 0;

		var d = scope.delta,
			fx2 = fx + d,
			fy2 = fy + d,
			fz2 = fz + d;

		// top of the cube

		if ( bits & 1 ) {

			compNorm( q );
			compNorm( q1 );
			VIntX( q * 3, 0, isol, fx, fy, fz, field0, field1, q, q1 );

		}

		if ( bits & 2 ) {

			compNorm( q1 );
			compNorm( q1y );
			VIntY( q1 * 3, 3, isol, fx2, fy, fz, field1, field3, q1, q1y );

		}

		if ( bits & 4 ) {

			compNorm( qy );
			compNorm( q1y );
			VIntX( qy * 3, 6, isol, fx, fy2, fz, field2, field3, qy, q1y );

		}

		if ( bits & 8 ) {

			compNorm( q );
			compNorm( qy );
			VIntY( q * 3, 9, isol, fx, fy, fz, field0, field2, q, qy );

		}

		// bottom of the cube

		if ( bits & 16 ) {

			compNorm( qz );
			compNorm( q1z );
			VIntX( qz * 3, 12, isol, fx, fy, fz2, field4, field5, qz, q1z );

		}

		if ( bits & 32 ) {

			compNorm( q1z );
			compNorm( q1yz );
			VIntY(
				q1z * 3,
				15,
				isol,
				fx2,
				fy,
				fz2,
				field5,
				field7,
				q1z,
				q1yz
			);

		}

		if ( bits & 64 ) {

			compNorm( qyz );
			compNorm( q1yz );
			VIntX(
				qyz * 3,
				18,
				isol,
				fx,
				fy2,
				fz2,
				field6,
				field7,
				qyz,
				q1yz
			);

		}

		if ( bits & 128 ) {

			compNorm( qz );
			compNorm( qyz );
			VIntY( qz * 3, 21, isol, fx, fy, fz2, field4, field6, qz, qyz );

		}

		// vertical lines of the cube
		if ( bits & 256 ) {

			compNorm( q );
			compNorm( qz );
			VIntZ( q * 3, 24, isol, fx, fy, fz, field0, field4, q, qz );

		}

		if ( bits & 512 ) {

			compNorm( q1 );
			compNorm( q1z );
			VIntZ( q1 * 3, 27, isol, fx2, fy, fz, field1, field5, q1, q1z );

		}

		if ( bits & 1024 ) {

			compNorm( q1y );
			compNorm( q1yz );
			VIntZ(
				q1y * 3,
				30,
				isol,
				fx2,
				fy2,
				fz,
				field3,
				field7,
				q1y,
				q1yz
			);

		}

		if ( bits & 2048 ) {

			compNorm( qy );
			compNorm( qyz );
			VIntZ( qy * 3, 33, isol, fx, fy2, fz, field2, field6, qy, qyz );

		}

		cubeindex <<= 4; // re-purpose cubeindex into an offset into triTable

		var o1,
			o2,
			o3,
			numtris = 0,
			i = 0;

		// here is where triangles are created

		while ( triTable[ cubeindex + i ] != - 1 ) {

			o1 = cubeindex + i;
			o2 = o1 + 1;
			o3 = o1 + 2;

			posnormtriv(
				vlist,
				nlist,
				clist,
				3 * triTable[ o1 ],
				3 * triTable[ o2 ],
				3 * triTable[ o3 ],
				renderCallback
			);

			i += 3;
			numtris ++;

		}

		return numtris;

	}

	/////////////////////////////////////
	// Immediate render mode simulator
	/////////////////////////////////////

	function posnormtriv( pos, norm, colors, o1, o2, o3, renderCallback ) {

		var c = scope.count * 3;

		// positions

		scope.positionArray[ c + 0 ] = pos[ o1 ];
		scope.positionArray[ c + 1 ] = pos[ o1 + 1 ];
		scope.positionArray[ c + 2 ] = pos[ o1 + 2 ];

		scope.positionArray[ c + 3 ] = pos[ o2 ];
		scope.positionArray[ c + 4 ] = pos[ o2 + 1 ];
		scope.positionArray[ c + 5 ] = pos[ o2 + 2 ];

		scope.positionArray[ c + 6 ] = pos[ o3 ];
		scope.positionArray[ c + 7 ] = pos[ o3 + 1 ];
		scope.positionArray[ c + 8 ] = pos[ o3 + 2 ];

		// normals

		if ( scope.material.flatShading === true ) {

			var nx = ( norm[ o1 + 0 ] + norm[ o2 + 0 ] + norm[ o3 + 0 ] ) / 3;
			var ny = ( norm[ o1 + 1 ] + norm[ o2 + 1 ] + norm[ o3 + 1 ] ) / 3;
			var nz = ( norm[ o1 + 2 ] + norm[ o2 + 2 ] + norm[ o3 + 2 ] ) / 3;

			scope.normalArray[ c + 0 ] = nx;
			scope.normalArray[ c + 1 ] = ny;
			scope.normalArray[ c + 2 ] = nz;

			scope.normalArray[ c + 3 ] = nx;
			scope.normalArray[ c + 4 ] = ny;
			scope.normalArray[ c + 5 ] = nz;

			scope.normalArray[ c + 6 ] = nx;
			scope.normalArray[ c + 7 ] = ny;
			scope.normalArray[ c + 8 ] = nz;

		} else {

			scope.normalArray[ c + 0 ] = norm[ o1 + 0 ];
			scope.normalArray[ c + 1 ] = norm[ o1 + 1 ];
			scope.normalArray[ c + 2 ] = norm[ o1 + 2 ];

			scope.normalArray[ c + 3 ] = norm[ o2 + 0 ];
			scope.normalArray[ c + 4 ] = norm[ o2 + 1 ];
			scope.normalArray[ c + 5 ] = norm[ o2 + 2 ];

			scope.normalArray[ c + 6 ] = norm[ o3 + 0 ];
			scope.normalArray[ c + 7 ] = norm[ o3 + 1 ];
			scope.normalArray[ c + 8 ] = norm[ o3 + 2 ];

		}

		// uvs

		if ( scope.enableUvs ) {

			var d = scope.count * 2;

			scope.uvArray[ d + 0 ] = pos[ o1 + 0 ];
			scope.uvArray[ d + 1 ] = pos[ o1 + 2 ];

			scope.uvArray[ d + 2 ] = pos[ o2 + 0 ];
			scope.uvArray[ d + 3 ] = pos[ o2 + 2 ];

			scope.uvArray[ d + 4 ] = pos[ o3 + 0 ];
			scope.uvArray[ d + 5 ] = pos[ o3 + 2 ];

		}

		// colors

		if ( scope.enableColors ) {

			scope.colorArray[ c + 0 ] = colors[ o1 + 0 ];
			scope.colorArray[ c + 1 ] = colors[ o1 + 1 ];
			scope.colorArray[ c + 2 ] = colors[ o1 + 2 ];

			scope.colorArray[ c + 3 ] = colors[ o2 + 0 ];
			scope.colorArray[ c + 4 ] = colors[ o2 + 1 ];
			scope.colorArray[ c + 5 ] = colors[ o2 + 2 ];

			scope.colorArray[ c + 6 ] = colors[ o3 + 0 ];
			scope.colorArray[ c + 7 ] = colors[ o3 + 1 ];
			scope.colorArray[ c + 8 ] = colors[ o3 + 2 ];

		}

		scope.count += 3;

		if ( scope.count >= scope.maxCount - 3 ) {

			scope.hasPositions = true;
			scope.hasNormals = true;

			if ( scope.enableUvs ) {

				scope.hasUvs = true;

			}

			if ( scope.enableColors ) {

				scope.hasColors = true;

			}

			renderCallback( scope );

		}

	}

	this.begin = function () {

		this.count = 0;

		this.hasPositions = false;
		this.hasNormals = false;
		this.hasUvs = false;
		this.hasColors = false;

	};

	this.end = function ( renderCallback ) {

		if ( this.count === 0 ) return;

		for ( var i = this.count * 3; i < this.positionArray.length; i ++ ) {

			this.positionArray[ i ] = 0.0;

		}

		this.hasPositions = true;
		this.hasNormals = true;

		if ( this.enableUvs && this.material.map ) {

			this.hasUvs = true;

		}

		if ( this.enableColors && this.material.vertexColors !== NoColors ) {

			this.hasColors = true;

		}

		renderCallback( this );

	};

	/////////////////////////////////////
	// Metaballs
	/////////////////////////////////////

	// Adds a reciprocal ball (nice and blobby) that, to be fast, fades to zero after
	// a fixed distance, determined by strength and subtract.

	this.addBall = function ( ballx, bally, ballz, strength, subtract, colors ) {

		var sign = Math.sign( strength );
		strength = Math.abs( strength );
		var userDefineColor = ! ( colors === undefined || colors === null );
		var ballColor = new Color( ballx, bally, ballz );
		if ( userDefineColor ) {

			try {

				ballColor =
					colors instanceof Color
						? colors
						: Array.isArray( colors )
							? new Color(
								Math.min( Math.abs( colors[ 0 ] ), 1 ),
								Math.min( Math.abs( colors[ 1 ] ), 1 ),
								Math.min( Math.abs( colors[ 2 ] ), 1 )
						  )
							: new Color( colors );

			} catch ( err ) {

				ballColor = new Color( ballx, bally, ballz );

			}

		}

		// Let's solve the equation to find the radius:
		// 1.0 / (0.000001 + radius^2) * strength - subtract = 0
		// strength / (radius^2) = subtract
		// strength = subtract * radius^2
		// radius^2 = strength / subtract
		// radius = sqrt(strength / subtract)

		var radius = this.size * Math.sqrt( strength / subtract ),
			zs = ballz * this.size,
			ys = bally * this.size,
			xs = ballx * this.size;

		var min_z = Math.floor( zs - radius );
		if ( min_z < 1 ) min_z = 1;
		var max_z = Math.floor( zs + radius );
		if ( max_z > this.size - 1 ) max_z = this.size - 1;
		var min_y = Math.floor( ys - radius );
		if ( min_y < 1 ) min_y = 1;
		var max_y = Math.floor( ys + radius );
		if ( max_y > this.size - 1 ) max_y = this.size - 1;
		var min_x = Math.floor( xs - radius );
		if ( min_x < 1 ) min_x = 1;
		var max_x = Math.floor( xs + radius );
		if ( max_x > this.size - 1 ) max_x = this.size - 1;

		// Don't polygonize in the outer layer because normals aren't
		// well-defined there.

		var x, y, z, y_offset, z_offset, fx, fy, fz, fz2, fy2, val;
		for ( z = min_z; z < max_z; z ++ ) {

			z_offset = this.size2 * z;
			fz = z / this.size - ballz;
			fz2 = fz * fz;

			for ( y = min_y; y < max_y; y ++ ) {

				y_offset = z_offset + this.size * y;
				fy = y / this.size - bally;
				fy2 = fy * fy;

				for ( x = min_x; x < max_x; x ++ ) {

					fx = x / this.size - ballx;
					val = strength / ( 0.000001 + fx * fx + fy2 + fz2 ) - subtract;
					if ( val > 0.0 ) {

						this.field[ y_offset + x ] += val * sign;

						// optimization
						// http://www.geisswerks.com/ryan/BLOBS/blobs.html
						const ratio =
							Math.sqrt( ( x - xs ) * ( x - xs ) + ( y - ys ) * ( y - ys ) + ( z - zs ) * ( z - zs ) ) / radius;
						const contrib =
							1 - ratio * ratio * ratio * ( ratio * ( ratio * 6 - 15 ) + 10 );
						this.palette[ ( y_offset + x ) * 3 + 0 ] += ballColor.r * contrib;
						this.palette[ ( y_offset + x ) * 3 + 1 ] += ballColor.g * contrib;
						this.palette[ ( y_offset + x ) * 3 + 2 ] += ballColor.b * contrib;

					}

				}

			}

		}

	};

	this.addPlaneX = function ( strength, subtract ) {

		var x,
			y,
			z,
			xx,
			val,
			xdiv,
			cxy,
			// cache attribute lookups
			size = this.size,
			yd = this.yd,
			zd = this.zd,
			field = this.field,
			dist = size * Math.sqrt( strength / subtract );

		if ( dist > size ) dist = size;

		for ( x = 0; x < dist; x ++ ) {

			xdiv = x / size;
			xx = xdiv * xdiv;
			val = strength / ( 0.0001 + xx ) - subtract;

			if ( val > 0.0 ) {

				for ( y = 0; y < size; y ++ ) {

					cxy = x + y * yd;

					for ( z = 0; z < size; z ++ ) {

						field[ zd * z + cxy ] += val;

					}

				}

			}

		}

	};

	this.addPlaneY = function ( strength, subtract ) {

		var x,
			y,
			z,
			yy,
			val,
			ydiv,
			cy,
			cxy,
			// cache attribute lookups
			size = this.size,
			yd = this.yd,
			zd = this.zd,
			field = this.field,
			dist = size * Math.sqrt( strength / subtract );

		if ( dist > size ) dist = size;

		for ( y = 0; y < dist; y ++ ) {

			ydiv = y / size;
			yy = ydiv * ydiv;
			val = strength / ( 0.0001 + yy ) - subtract;

			if ( val > 0.0 ) {

				cy = y * yd;

				for ( x = 0; x < size; x ++ ) {

					cxy = cy + x;

					for ( z = 0; z < size; z ++ ) field[ zd * z + cxy ] += val;

				}

			}

		}

	};

	this.addPlaneZ = function ( strength, subtract ) {

		var x,
			y,
			z,
			zz,
			val,
			zdiv,
			cz,
			cyz,
			// cache attribute lookups
			size = this.size,
			yd = this.yd,
			zd = this.zd,
			field = this.field,
			dist = size * Math.sqrt( strength / subtract );

		if ( dist > size ) dist = size;

		for ( z = 0; z < dist; z ++ ) {

			zdiv = z / size;
			zz = zdiv * zdiv;
			val = strength / ( 0.0001 + zz ) - subtract;
			if ( val > 0.0 ) {

				cz = zd * z;

				for ( y = 0; y < size; y ++ ) {

					cyz = cz + y * yd;

					for ( x = 0; x < size; x ++ ) field[ cyz + x ] += val;

				}

			}

		}

	};

	/////////////////////////////////////
	// Updates
	/////////////////////////////////////

	this.setCell = function ( x, y, z, value ) {

		var index = this.size2 * z + this.size * y + x;
		this.field[ index ] = value;

	};

	this.getCell = function ( x, y, z ) {

		var index = this.size2 * z + this.size * y + x;
		return this.field[ index ];

	};

	this.blur = function ( intensity ) {

		if ( intensity === undefined ) {

			intensity = 1;

		}

		var field = this.field;
		var fieldCopy = field.slice();
		var size = this.size;
		var size2 = this.size2;
		for ( var x = 0; x < size; x ++ ) {

			for ( var y = 0; y < size; y ++ ) {

				for ( var z = 0; z < size; z ++ ) {

					var index = size2 * z + size * y + x;
					var val = fieldCopy[ index ];
					var count = 1;

					for ( var x2 = - 1; x2 <= 1; x2 += 2 ) {

						var x3 = x2 + x;
						if ( x3 < 0 || x3 >= size ) continue;

						for ( var y2 = - 1; y2 <= 1; y2 += 2 ) {

							var y3 = y2 + y;
							if ( y3 < 0 || y3 >= size ) continue;

							for ( var z2 = - 1; z2 <= 1; z2 += 2 ) {

								var z3 = z2 + z;
								if ( z3 < 0 || z3 >= size ) continue;

								var index2 = size2 * z3 + size * y3 + x3;
								var val2 = fieldCopy[ index2 ];

								count ++;
								val += intensity * ( val2 - val ) / count;

							}

						}

					}

					field[ index ] = val;

				}

			}

		}

	};

	this.reset = function () {

		var i;

		// wipe the normal cache

		for ( i = 0; i < this.size3; i ++ ) {

			this.normal_cache[ i * 3 ] = 0.0;
			this.field[ i ] = 0.0;
			this.palette[ i * 3 ] = this.palette[ i * 3 + 1 ] = this.palette[
				i * 3 + 2
			] = 0.0;

		}

	};

	this.render = function ( renderCallback ) {

		this.begin();

		// Triangulate. Yeah, this is slow.

		var smin2 = this.size - 2;

		for ( var z = 1; z < smin2; z ++ ) {

			var z_offset = this.size2 * z;
			var fz = ( z - this.halfsize ) / this.halfsize; //+ 1

			for ( var y = 1; y < smin2; y ++ ) {

				var y_offset = z_offset + this.size * y;
				var fy = ( y - this.halfsize ) / this.halfsize; //+ 1

				for ( var x = 1; x < smin2; x ++ ) {

					var fx = ( x - this.halfsize ) / this.halfsize; //+ 1
					var q = y_offset + x;

					polygonize( fx, fy, fz, q, this.isolation, renderCallback );

				}

			}

		}

		this.end( renderCallback );

	};

	this.generateGeometry = function () {

		console.warn(
			"MarchingCubes: generateGeometry() now returns BufferGeometry"
		);
		return this.generateBufferGeometry();

	};

	function concatenate( a, b, length ) {

		var result = new Float32Array( a.length + length );
		result.set( a, 0 );
		result.set( b.slice( 0, length ), a.length );
		return result;

	}

	this.generateBufferGeometry = function () {

		var geo = new BufferGeometry();
		var posArray = new Float32Array();
		var normArray = new Float32Array();
		var colorArray = new Float32Array();
		var uvArray = new Float32Array();
		var scope = this;

		var geo_callback = function ( object ) {

			if ( scope.hasPositions )
				posArray = concatenate(
					posArray,
					object.positionArray,
					object.count * 3
				);
			if ( scope.hasNormals )
				normArray = concatenate(
					normArray,
					object.normalArray,
					object.count * 3
				);
			if ( scope.hasColors )
				colorArray = concatenate(
					colorArray,
					object.colorArray,
					object.count * 3
				);
			if ( scope.hasUvs )
				uvArray = concatenate( uvArray, object.uvArray, object.count * 2 );

			object.count = 0;

		};

		this.render( geo_callback );

		if ( this.hasPositions )
			geo.setAttribute( "position", new BufferAttribute( posArray, 3 ) );
		if ( this.hasNormals )
			geo.setAttribute( "normal", new BufferAttribute( normArray, 3 ) );
		if ( this.hasColors )
			geo.setAttribute( "color", new BufferAttribute( colorArray, 3 ) );
		if ( this.hasUvs )
			geo.setAttribute( "uv", new BufferAttribute( uvArray, 2 ) );

		return geo;

	};

	this.init( resolution );

};

MarchingCubes.prototype = Object.create( ImmediateRenderObject.prototype );
MarchingCubes.prototype.constructor = MarchingCubes;

/////////////////////////////////////
// Marching cubes lookup tables
/////////////////////////////////////

// These tables are straight from Paul Bourke's page:
// http://local.wasp.uwa.edu.au/~pbourke/geometry/polygonise/
// who in turn got them from Cory Gene Bloyd.

var edgeTable = new Int32Array( [
	0x0, 0x109, 0x203, 0x30a, 0x406, 0x50f, 0x605, 0x70c,
	0x80c, 0x905, 0xa0f, 0xb06, 0xc0a, 0xd03, 0xe09, 0xf00,
	0x190, 0x99, 0x393, 0x29a, 0x596, 0x49f, 0x795, 0x69c,
	0x99c, 0x895, 0xb9f, 0xa96, 0xd9a, 0xc93, 0xf99, 0xe90,
	0x230, 0x339, 0x33, 0x13a, 0x636, 0x73f, 0x435, 0x53c,
	0xa3c, 0xb35, 0x83f, 0x936, 0xe3a, 0xf33, 0xc39, 0xd30,
	0x3a0, 0x2a9, 0x1a3, 0xaa, 0x7a6, 0x6af, 0x5a5, 0x4ac,
	0xbac, 0xaa5, 0x9af, 0x8a6, 0xfaa, 0xea3, 0xda9, 0xca0,
	0x460, 0x569, 0x663, 0x76a, 0x66, 0x16f, 0x265, 0x36c,
	0xc6c, 0xd65, 0xe6f, 0xf66, 0x86a, 0x963, 0xa69, 0xb60,
	0x5f0, 0x4f9, 0x7f3, 0x6fa, 0x1f6, 0xff, 0x3f5, 0x2fc,
	0xdfc, 0xcf5, 0xfff, 0xef6, 0x9fa, 0x8f3, 0xbf9, 0xaf0,
	0x650, 0x759, 0x453, 0x55a, 0x256, 0x35f, 0x55, 0x15c,
	0xe5c, 0xf55, 0xc5f, 0xd56, 0xa5a, 0xb53, 0x859, 0x950,
	0x7c0, 0x6c9, 0x5c3, 0x4ca, 0x3c6, 0x2cf, 0x1c5, 0xcc,
	0xfcc, 0xec5, 0xdcf, 0xcc6, 0xbca, 0xac3, 0x9c9, 0x8c0,
	0x8c0, 0x9c9, 0xac3, 0xbca, 0xcc6, 0xdcf, 0xec5, 0xfcc,
	0xcc, 0x1c5, 0x2cf, 0x3c6, 0x4ca, 0x5c3, 0x6c9, 0x7c0,
	0x950, 0x859, 0xb53, 0xa5a, 0xd56, 0xc5f, 0xf55, 0xe5c,
	0x15c, 0x55, 0x35f, 0x256, 0x55a, 0x453, 0x759, 0x650,
	0xaf0, 0xbf9, 0x8f3, 0x9fa, 0xef6, 0xfff, 0xcf5, 0xdfc,
	0x2fc, 0x3f5, 0xff, 0x1f6, 0x6fa, 0x7f3, 0x4f9, 0x5f0,
	0xb60, 0xa69, 0x963, 0x86a, 0xf66, 0xe6f, 0xd65, 0xc6c,
	0x36c, 0x265, 0x16f, 0x66, 0x76a, 0x663, 0x569, 0x460,
	0xca0, 0xda9, 0xea3, 0xfaa, 0x8a6, 0x9af, 0xaa5, 0xbac,
	0x4ac, 0x5a5, 0x6af, 0x7a6, 0xaa, 0x1a3, 0x2a9, 0x3a0,
	0xd30, 0xc39, 0xf33, 0xe3a, 0x936, 0x83f, 0xb35, 0xa3c,
	0x53c, 0x435, 0x73f, 0x636, 0x13a, 0x33, 0x339, 0x230,
	0xe90, 0xf99, 0xc93, 0xd9a, 0xa96, 0xb9f, 0x895, 0x99c,
	0x69c, 0x795, 0x49f, 0x596, 0x29a, 0x393, 0x99, 0x190,
	0xf00, 0xe09, 0xd03, 0xc0a, 0xb06, 0xa0f, 0x905, 0x80c,
	0x70c, 0x605, 0x50f, 0x406, 0x30a, 0x203, 0x109, 0x0 ] );

var triTable = new Int32Array( [
	- 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 1, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 8, 3, 9, 8, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, 1, 2, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 2, 10, 0, 2, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 8, 3, 2, 10, 8, 10, 9, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 11, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 11, 2, 8, 11, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 9, 0, 2, 3, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 11, 2, 1, 9, 11, 9, 8, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 10, 1, 11, 10, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 10, 1, 0, 8, 10, 8, 11, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 9, 0, 3, 11, 9, 11, 10, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 8, 10, 10, 8, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 7, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 3, 0, 7, 3, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 1, 9, 8, 4, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 1, 9, 4, 7, 1, 7, 3, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, 8, 4, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 4, 7, 3, 0, 4, 1, 2, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 2, 10, 9, 0, 2, 8, 4, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 10, 9, 2, 9, 7, 2, 7, 3, 7, 9, 4, - 1, - 1, - 1, - 1,
	8, 4, 7, 3, 11, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 4, 7, 11, 2, 4, 2, 0, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 0, 1, 8, 4, 7, 2, 3, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 7, 11, 9, 4, 11, 9, 11, 2, 9, 2, 1, - 1, - 1, - 1, - 1,
	3, 10, 1, 3, 11, 10, 7, 8, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 11, 10, 1, 4, 11, 1, 0, 4, 7, 11, 4, - 1, - 1, - 1, - 1,
	4, 7, 8, 9, 0, 11, 9, 11, 10, 11, 0, 3, - 1, - 1, - 1, - 1,
	4, 7, 11, 4, 11, 9, 9, 11, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 5, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 5, 4, 0, 8, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 5, 4, 1, 5, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 5, 4, 8, 3, 5, 3, 1, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, 9, 5, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 0, 8, 1, 2, 10, 4, 9, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 2, 10, 5, 4, 2, 4, 0, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 10, 5, 3, 2, 5, 3, 5, 4, 3, 4, 8, - 1, - 1, - 1, - 1,
	9, 5, 4, 2, 3, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 11, 2, 0, 8, 11, 4, 9, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 5, 4, 0, 1, 5, 2, 3, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 1, 5, 2, 5, 8, 2, 8, 11, 4, 8, 5, - 1, - 1, - 1, - 1,
	10, 3, 11, 10, 1, 3, 9, 5, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 9, 5, 0, 8, 1, 8, 10, 1, 8, 11, 10, - 1, - 1, - 1, - 1,
	5, 4, 0, 5, 0, 11, 5, 11, 10, 11, 0, 3, - 1, - 1, - 1, - 1,
	5, 4, 8, 5, 8, 10, 10, 8, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 7, 8, 5, 7, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 3, 0, 9, 5, 3, 5, 7, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 7, 8, 0, 1, 7, 1, 5, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 5, 3, 3, 5, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 7, 8, 9, 5, 7, 10, 1, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 1, 2, 9, 5, 0, 5, 3, 0, 5, 7, 3, - 1, - 1, - 1, - 1,
	8, 0, 2, 8, 2, 5, 8, 5, 7, 10, 5, 2, - 1, - 1, - 1, - 1,
	2, 10, 5, 2, 5, 3, 3, 5, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 9, 5, 7, 8, 9, 3, 11, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 5, 7, 9, 7, 2, 9, 2, 0, 2, 7, 11, - 1, - 1, - 1, - 1,
	2, 3, 11, 0, 1, 8, 1, 7, 8, 1, 5, 7, - 1, - 1, - 1, - 1,
	11, 2, 1, 11, 1, 7, 7, 1, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 5, 8, 8, 5, 7, 10, 1, 3, 10, 3, 11, - 1, - 1, - 1, - 1,
	5, 7, 0, 5, 0, 9, 7, 11, 0, 1, 0, 10, 11, 10, 0, - 1,
	11, 10, 0, 11, 0, 3, 10, 5, 0, 8, 0, 7, 5, 7, 0, - 1,
	11, 10, 5, 7, 11, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 6, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, 5, 10, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 0, 1, 5, 10, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 8, 3, 1, 9, 8, 5, 10, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 6, 5, 2, 6, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 6, 5, 1, 2, 6, 3, 0, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 6, 5, 9, 0, 6, 0, 2, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 9, 8, 5, 8, 2, 5, 2, 6, 3, 2, 8, - 1, - 1, - 1, - 1,
	2, 3, 11, 10, 6, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 0, 8, 11, 2, 0, 10, 6, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 1, 9, 2, 3, 11, 5, 10, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 10, 6, 1, 9, 2, 9, 11, 2, 9, 8, 11, - 1, - 1, - 1, - 1,
	6, 3, 11, 6, 5, 3, 5, 1, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 11, 0, 11, 5, 0, 5, 1, 5, 11, 6, - 1, - 1, - 1, - 1,
	3, 11, 6, 0, 3, 6, 0, 6, 5, 0, 5, 9, - 1, - 1, - 1, - 1,
	6, 5, 9, 6, 9, 11, 11, 9, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 10, 6, 4, 7, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 3, 0, 4, 7, 3, 6, 5, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 9, 0, 5, 10, 6, 8, 4, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 6, 5, 1, 9, 7, 1, 7, 3, 7, 9, 4, - 1, - 1, - 1, - 1,
	6, 1, 2, 6, 5, 1, 4, 7, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 5, 5, 2, 6, 3, 0, 4, 3, 4, 7, - 1, - 1, - 1, - 1,
	8, 4, 7, 9, 0, 5, 0, 6, 5, 0, 2, 6, - 1, - 1, - 1, - 1,
	7, 3, 9, 7, 9, 4, 3, 2, 9, 5, 9, 6, 2, 6, 9, - 1,
	3, 11, 2, 7, 8, 4, 10, 6, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 10, 6, 4, 7, 2, 4, 2, 0, 2, 7, 11, - 1, - 1, - 1, - 1,
	0, 1, 9, 4, 7, 8, 2, 3, 11, 5, 10, 6, - 1, - 1, - 1, - 1,
	9, 2, 1, 9, 11, 2, 9, 4, 11, 7, 11, 4, 5, 10, 6, - 1,
	8, 4, 7, 3, 11, 5, 3, 5, 1, 5, 11, 6, - 1, - 1, - 1, - 1,
	5, 1, 11, 5, 11, 6, 1, 0, 11, 7, 11, 4, 0, 4, 11, - 1,
	0, 5, 9, 0, 6, 5, 0, 3, 6, 11, 6, 3, 8, 4, 7, - 1,
	6, 5, 9, 6, 9, 11, 4, 7, 9, 7, 11, 9, - 1, - 1, - 1, - 1,
	10, 4, 9, 6, 4, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 10, 6, 4, 9, 10, 0, 8, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 0, 1, 10, 6, 0, 6, 4, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 3, 1, 8, 1, 6, 8, 6, 4, 6, 1, 10, - 1, - 1, - 1, - 1,
	1, 4, 9, 1, 2, 4, 2, 6, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 0, 8, 1, 2, 9, 2, 4, 9, 2, 6, 4, - 1, - 1, - 1, - 1,
	0, 2, 4, 4, 2, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 3, 2, 8, 2, 4, 4, 2, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 4, 9, 10, 6, 4, 11, 2, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 2, 2, 8, 11, 4, 9, 10, 4, 10, 6, - 1, - 1, - 1, - 1,
	3, 11, 2, 0, 1, 6, 0, 6, 4, 6, 1, 10, - 1, - 1, - 1, - 1,
	6, 4, 1, 6, 1, 10, 4, 8, 1, 2, 1, 11, 8, 11, 1, - 1,
	9, 6, 4, 9, 3, 6, 9, 1, 3, 11, 6, 3, - 1, - 1, - 1, - 1,
	8, 11, 1, 8, 1, 0, 11, 6, 1, 9, 1, 4, 6, 4, 1, - 1,
	3, 11, 6, 3, 6, 0, 0, 6, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	6, 4, 8, 11, 6, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 10, 6, 7, 8, 10, 8, 9, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 7, 3, 0, 10, 7, 0, 9, 10, 6, 7, 10, - 1, - 1, - 1, - 1,
	10, 6, 7, 1, 10, 7, 1, 7, 8, 1, 8, 0, - 1, - 1, - 1, - 1,
	10, 6, 7, 10, 7, 1, 1, 7, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 6, 1, 6, 8, 1, 8, 9, 8, 6, 7, - 1, - 1, - 1, - 1,
	2, 6, 9, 2, 9, 1, 6, 7, 9, 0, 9, 3, 7, 3, 9, - 1,
	7, 8, 0, 7, 0, 6, 6, 0, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 3, 2, 6, 7, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 3, 11, 10, 6, 8, 10, 8, 9, 8, 6, 7, - 1, - 1, - 1, - 1,
	2, 0, 7, 2, 7, 11, 0, 9, 7, 6, 7, 10, 9, 10, 7, - 1,
	1, 8, 0, 1, 7, 8, 1, 10, 7, 6, 7, 10, 2, 3, 11, - 1,
	11, 2, 1, 11, 1, 7, 10, 6, 1, 6, 7, 1, - 1, - 1, - 1, - 1,
	8, 9, 6, 8, 6, 7, 9, 1, 6, 11, 6, 3, 1, 3, 6, - 1,
	0, 9, 1, 11, 6, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 8, 0, 7, 0, 6, 3, 11, 0, 11, 6, 0, - 1, - 1, - 1, - 1,
	7, 11, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 6, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 0, 8, 11, 7, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 1, 9, 11, 7, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 1, 9, 8, 3, 1, 11, 7, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 1, 2, 6, 11, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, 3, 0, 8, 6, 11, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 9, 0, 2, 10, 9, 6, 11, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	6, 11, 7, 2, 10, 3, 10, 8, 3, 10, 9, 8, - 1, - 1, - 1, - 1,
	7, 2, 3, 6, 2, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	7, 0, 8, 7, 6, 0, 6, 2, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 7, 6, 2, 3, 7, 0, 1, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 6, 2, 1, 8, 6, 1, 9, 8, 8, 7, 6, - 1, - 1, - 1, - 1,
	10, 7, 6, 10, 1, 7, 1, 3, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 7, 6, 1, 7, 10, 1, 8, 7, 1, 0, 8, - 1, - 1, - 1, - 1,
	0, 3, 7, 0, 7, 10, 0, 10, 9, 6, 10, 7, - 1, - 1, - 1, - 1,
	7, 6, 10, 7, 10, 8, 8, 10, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	6, 8, 4, 11, 8, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 6, 11, 3, 0, 6, 0, 4, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 6, 11, 8, 4, 6, 9, 0, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 4, 6, 9, 6, 3, 9, 3, 1, 11, 3, 6, - 1, - 1, - 1, - 1,
	6, 8, 4, 6, 11, 8, 2, 10, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, 3, 0, 11, 0, 6, 11, 0, 4, 6, - 1, - 1, - 1, - 1,
	4, 11, 8, 4, 6, 11, 0, 2, 9, 2, 10, 9, - 1, - 1, - 1, - 1,
	10, 9, 3, 10, 3, 2, 9, 4, 3, 11, 3, 6, 4, 6, 3, - 1,
	8, 2, 3, 8, 4, 2, 4, 6, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 4, 2, 4, 6, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 9, 0, 2, 3, 4, 2, 4, 6, 4, 3, 8, - 1, - 1, - 1, - 1,
	1, 9, 4, 1, 4, 2, 2, 4, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 1, 3, 8, 6, 1, 8, 4, 6, 6, 10, 1, - 1, - 1, - 1, - 1,
	10, 1, 0, 10, 0, 6, 6, 0, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 6, 3, 4, 3, 8, 6, 10, 3, 0, 3, 9, 10, 9, 3, - 1,
	10, 9, 4, 6, 10, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 9, 5, 7, 6, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, 4, 9, 5, 11, 7, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 0, 1, 5, 4, 0, 7, 6, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 7, 6, 8, 3, 4, 3, 5, 4, 3, 1, 5, - 1, - 1, - 1, - 1,
	9, 5, 4, 10, 1, 2, 7, 6, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	6, 11, 7, 1, 2, 10, 0, 8, 3, 4, 9, 5, - 1, - 1, - 1, - 1,
	7, 6, 11, 5, 4, 10, 4, 2, 10, 4, 0, 2, - 1, - 1, - 1, - 1,
	3, 4, 8, 3, 5, 4, 3, 2, 5, 10, 5, 2, 11, 7, 6, - 1,
	7, 2, 3, 7, 6, 2, 5, 4, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 5, 4, 0, 8, 6, 0, 6, 2, 6, 8, 7, - 1, - 1, - 1, - 1,
	3, 6, 2, 3, 7, 6, 1, 5, 0, 5, 4, 0, - 1, - 1, - 1, - 1,
	6, 2, 8, 6, 8, 7, 2, 1, 8, 4, 8, 5, 1, 5, 8, - 1,
	9, 5, 4, 10, 1, 6, 1, 7, 6, 1, 3, 7, - 1, - 1, - 1, - 1,
	1, 6, 10, 1, 7, 6, 1, 0, 7, 8, 7, 0, 9, 5, 4, - 1,
	4, 0, 10, 4, 10, 5, 0, 3, 10, 6, 10, 7, 3, 7, 10, - 1,
	7, 6, 10, 7, 10, 8, 5, 4, 10, 4, 8, 10, - 1, - 1, - 1, - 1,
	6, 9, 5, 6, 11, 9, 11, 8, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 6, 11, 0, 6, 3, 0, 5, 6, 0, 9, 5, - 1, - 1, - 1, - 1,
	0, 11, 8, 0, 5, 11, 0, 1, 5, 5, 6, 11, - 1, - 1, - 1, - 1,
	6, 11, 3, 6, 3, 5, 5, 3, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 10, 9, 5, 11, 9, 11, 8, 11, 5, 6, - 1, - 1, - 1, - 1,
	0, 11, 3, 0, 6, 11, 0, 9, 6, 5, 6, 9, 1, 2, 10, - 1,
	11, 8, 5, 11, 5, 6, 8, 0, 5, 10, 5, 2, 0, 2, 5, - 1,
	6, 11, 3, 6, 3, 5, 2, 10, 3, 10, 5, 3, - 1, - 1, - 1, - 1,
	5, 8, 9, 5, 2, 8, 5, 6, 2, 3, 8, 2, - 1, - 1, - 1, - 1,
	9, 5, 6, 9, 6, 0, 0, 6, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 5, 8, 1, 8, 0, 5, 6, 8, 3, 8, 2, 6, 2, 8, - 1,
	1, 5, 6, 2, 1, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 3, 6, 1, 6, 10, 3, 8, 6, 5, 6, 9, 8, 9, 6, - 1,
	10, 1, 0, 10, 0, 6, 9, 5, 0, 5, 6, 0, - 1, - 1, - 1, - 1,
	0, 3, 8, 5, 6, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 5, 6, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 5, 10, 7, 5, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 5, 10, 11, 7, 5, 8, 3, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 11, 7, 5, 10, 11, 1, 9, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	10, 7, 5, 10, 11, 7, 9, 8, 1, 8, 3, 1, - 1, - 1, - 1, - 1,
	11, 1, 2, 11, 7, 1, 7, 5, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, 1, 2, 7, 1, 7, 5, 7, 2, 11, - 1, - 1, - 1, - 1,
	9, 7, 5, 9, 2, 7, 9, 0, 2, 2, 11, 7, - 1, - 1, - 1, - 1,
	7, 5, 2, 7, 2, 11, 5, 9, 2, 3, 2, 8, 9, 8, 2, - 1,
	2, 5, 10, 2, 3, 5, 3, 7, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 2, 0, 8, 5, 2, 8, 7, 5, 10, 2, 5, - 1, - 1, - 1, - 1,
	9, 0, 1, 5, 10, 3, 5, 3, 7, 3, 10, 2, - 1, - 1, - 1, - 1,
	9, 8, 2, 9, 2, 1, 8, 7, 2, 10, 2, 5, 7, 5, 2, - 1,
	1, 3, 5, 3, 7, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 7, 0, 7, 1, 1, 7, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 0, 3, 9, 3, 5, 5, 3, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 8, 7, 5, 9, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 8, 4, 5, 10, 8, 10, 11, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	5, 0, 4, 5, 11, 0, 5, 10, 11, 11, 3, 0, - 1, - 1, - 1, - 1,
	0, 1, 9, 8, 4, 10, 8, 10, 11, 10, 4, 5, - 1, - 1, - 1, - 1,
	10, 11, 4, 10, 4, 5, 11, 3, 4, 9, 4, 1, 3, 1, 4, - 1,
	2, 5, 1, 2, 8, 5, 2, 11, 8, 4, 5, 8, - 1, - 1, - 1, - 1,
	0, 4, 11, 0, 11, 3, 4, 5, 11, 2, 11, 1, 5, 1, 11, - 1,
	0, 2, 5, 0, 5, 9, 2, 11, 5, 4, 5, 8, 11, 8, 5, - 1,
	9, 4, 5, 2, 11, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 5, 10, 3, 5, 2, 3, 4, 5, 3, 8, 4, - 1, - 1, - 1, - 1,
	5, 10, 2, 5, 2, 4, 4, 2, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 10, 2, 3, 5, 10, 3, 8, 5, 4, 5, 8, 0, 1, 9, - 1,
	5, 10, 2, 5, 2, 4, 1, 9, 2, 9, 4, 2, - 1, - 1, - 1, - 1,
	8, 4, 5, 8, 5, 3, 3, 5, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 4, 5, 1, 0, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	8, 4, 5, 8, 5, 3, 9, 0, 5, 0, 3, 5, - 1, - 1, - 1, - 1,
	9, 4, 5, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 11, 7, 4, 9, 11, 9, 10, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 8, 3, 4, 9, 7, 9, 11, 7, 9, 10, 11, - 1, - 1, - 1, - 1,
	1, 10, 11, 1, 11, 4, 1, 4, 0, 7, 4, 11, - 1, - 1, - 1, - 1,
	3, 1, 4, 3, 4, 8, 1, 10, 4, 7, 4, 11, 10, 11, 4, - 1,
	4, 11, 7, 9, 11, 4, 9, 2, 11, 9, 1, 2, - 1, - 1, - 1, - 1,
	9, 7, 4, 9, 11, 7, 9, 1, 11, 2, 11, 1, 0, 8, 3, - 1,
	11, 7, 4, 11, 4, 2, 2, 4, 0, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	11, 7, 4, 11, 4, 2, 8, 3, 4, 3, 2, 4, - 1, - 1, - 1, - 1,
	2, 9, 10, 2, 7, 9, 2, 3, 7, 7, 4, 9, - 1, - 1, - 1, - 1,
	9, 10, 7, 9, 7, 4, 10, 2, 7, 8, 7, 0, 2, 0, 7, - 1,
	3, 7, 10, 3, 10, 2, 7, 4, 10, 1, 10, 0, 4, 0, 10, - 1,
	1, 10, 2, 8, 7, 4, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 9, 1, 4, 1, 7, 7, 1, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 9, 1, 4, 1, 7, 0, 8, 1, 8, 7, 1, - 1, - 1, - 1, - 1,
	4, 0, 3, 7, 4, 3, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	4, 8, 7, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 10, 8, 10, 11, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 0, 9, 3, 9, 11, 11, 9, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 1, 10, 0, 10, 8, 8, 10, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 1, 10, 11, 3, 10, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 2, 11, 1, 11, 9, 9, 11, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 0, 9, 3, 9, 11, 1, 2, 9, 2, 11, 9, - 1, - 1, - 1, - 1,
	0, 2, 11, 8, 0, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	3, 2, 11, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 3, 8, 2, 8, 10, 10, 8, 9, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	9, 10, 2, 0, 9, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	2, 3, 8, 2, 8, 10, 0, 1, 8, 1, 10, 8, - 1, - 1, - 1, - 1,
	1, 10, 2, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	1, 3, 8, 9, 1, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 9, 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	0, 3, 8, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1,
	- 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1 ] );

export { MarchingCubes, edgeTable, triTable };