text: THREE.Lut = function ( colormap, numberofcolors ) {
  
  	this.lut = [];
  	this.setColorMap( colormap, numberofcolors );
  	return this;
  
  };
  
  THREE.Lut.prototype = {
  
  	constructor: THREE.Lut,
  
  	lut: [], map: [], n: 256, minV: 0, maxV: 1,
  
  	set: function ( value ) {
  
  		if ( value instanceof THREE.Lut ) {
  
  			this.copy( value );
  
  		}
  
  		return this;
  
  	},
  
  	setMin: function ( min ) {
  
  		this.minV = min;
  
  		return this;
  
  	},
  
  	setMax: function ( max ) {
  
  		this.maxV = max;
  
  		return this;
  
  	},
  
  	setColorMap: function ( colormap, numberofcolors ) {
  
  		this.map = THREE.ColorMapKeywords[ colormap ] || THREE.ColorMapKeywords.rainbow;
  		this.n = numberofcolors || 32;
  
  		var step = 1.0 / this.n;
  
  		this.lut.length = 0;
  		for ( var i = 0; i <= 1; i += step ) {
  
  			for ( var j = 0; j < this.map.length - 1; j ++ ) {
  
  				if ( i >= this.map[ j ][ 0 ] && i < this.map[ j + 1 ][ 0 ] ) {
  
  					var min = this.map[ j ][ 0 ];
  					var max = this.map[ j + 1 ][ 0 ];
  
  					var minColor = new THREE.Color( this.map[ j ][ 1 ] );
  					var maxColor = new THREE.Color( this.map[ j + 1 ][ 1 ] );
  
  					var color = minColor.lerp( maxColor, ( i - min ) / ( max - min ) );
  
  					this.lut.push( color );
  
  				}
  
  			}
  
  		}
  
  		return this;
  
  	},
  
  	copy: function ( lut ) {
  
  		this.lut = lut.lut;
  		this.map = lut.map;
  		this.n = lut.n;
  		this.minV = lut.minV;
  		this.maxV = lut.maxV;
  
  		return this;
  
  	},
  
  	getColor: function ( alpha ) {
  
  		if ( alpha <= this.minV ) {
  
  			alpha = this.minV;
  
  		} else if ( alpha >= this.maxV ) {
  
  			alpha = this.maxV;
  
  		}
  
  		alpha = ( alpha - this.minV ) / ( this.maxV - this.minV );
  
  		var colorPosition = Math.round( alpha * this.n );
  		colorPosition == this.n ? colorPosition -= 1 : colorPosition;
  
  		return this.lut[ colorPosition ];
  
  	},
  
  	addColorMap: function ( colormapName, arrayOfColors ) {
  
  		THREE.ColorMapKeywords[ colormapName ] = arrayOfColors;
  
  	},
  
  	createCanvas: function () {
  
  		var canvas = document.createElement( 'canvas' );
  		canvas.width = 1;
  		canvas.height = this.n;
  
  		this.updateCanvas( canvas );
  
  		return canvas;
  
  	},
  
  	updateCanvas: function ( canvas ) {
  
  		var ctx = canvas.getContext( '2d', { alpha: false } );
  
  		var imageData = ctx.getImageData( 0, 0, 1, this.n );
  
  		var data = imageData.data;
  
  		var k = 0;
  
  		var step = 1.0 / this.n;
  
  		for ( var i = 1; i >= 0; i -= step ) {
  
  			for ( var j = this.map.length - 1; j >= 0; j -- ) {
  
  				if ( i < this.map[ j ][ 0 ] && i >= this.map[ j - 1 ][ 0 ] ) {
  
  					var min = this.map[ j - 1 ][ 0 ];
  					var max = this.map[ j ][ 0 ];
  
  					var minColor = new THREE.Color( this.map[ j - 1 ][ 1 ] );
  					var maxColor = new THREE.Color( this.map[ j ][ 1 ] );
  
  					var color = minColor.lerp( maxColor, ( i - min ) / ( max - min ) );
  
  					data[ k * 4 ] = Math.round( color.r * 255 );
  					data[ k * 4 + 1 ] = Math.round( color.g * 255 );
  					data[ k * 4 + 2 ] = Math.round( color.b * 255 );
  					data[ k * 4 + 3 ] = 255;
  
  					k += 1;
  
  				}
  
  			}
  
  		}
  
  		ctx.putImageData( imageData, 0, 0 );
  
  		return canvas;
  
  	}
  };
  
  THREE.ColorMapKeywords = {
  
  	'rainbow': [[ 0.0, 0x0000FF ], [ 0.2, 0x00FFFF ], [ 0.5, 0x00FF00 ], [ 0.8, 0xFFFF00 ], [ 1.0, 0xFF0000 ]],
  	'cooltowarm': [[ 0.0, 0x3C4EC2 ], [ 0.2, 0x9BBCFF ], [ 0.5, 0xDCDCDC ], [ 0.8, 0xF6A385 ], [ 1.0, 0xB40426 ]],
  	'blackbody': [[ 0.0, 0x000000 ], [ 0.2, 0x780000 ], [ 0.5, 0xE63200 ], [ 0.8, 0xFFFF00 ], [ 1.0, 0xFFFFFF ]],
  	'grayscale': [[ 0.0, 0x000000 ], [ 0.2, 0x404040 ], [ 0.5, 0x7F7F80 ], [ 0.8, 0xBFBFBF ], [ 1.0, 0xFFFFFF ]]
  
  };
  