2 * @author alteredq / http://alteredqualia.com/
3 * @author mrdoob / http://mrdoob.com/
4 * @author Daosheng Mu / https://github.com/DaoshengMu/
9 getNormalMap: function ( image, depth ) {
11 // Adapted from http://www.paulbrunt.co.uk/lab/heightnormal/
13 function cross( a, b ) {
15 return [ a[ 1 ] * b[ 2 ] - a[ 2 ] * b[ 1 ], a[ 2 ] * b[ 0 ] - a[ 0 ] * b[ 2 ], a[ 0 ] * b[ 1 ] - a[ 1 ] * b[ 0 ] ];
19 function subtract( a, b ) {
21 return [ a[ 0 ] - b[ 0 ], a[ 1 ] - b[ 1 ], a[ 2 ] - b[ 2 ] ];
25 function normalize( a ) {
27 var l = Math.sqrt( a[ 0 ] * a[ 0 ] + a[ 1 ] * a[ 1 ] + a[ 2 ] * a[ 2 ] );
28 return [ a[ 0 ] / l, a[ 1 ] / l, a[ 2 ] / l ];
34 var width = image.width;
35 var height = image.height;
37 var canvas = document.createElement( 'canvas' );
39 canvas.height = height;
41 var context = canvas.getContext( '2d' );
42 context.drawImage( image, 0, 0 );
44 var data = context.getImageData( 0, 0, width, height ).data;
45 var imageData = context.createImageData( width, height );
46 var output = imageData.data;
48 for ( var x = 0; x < width; x ++ ) {
50 for ( var y = 0; y < height; y ++ ) {
52 var ly = y - 1 < 0 ? 0 : y - 1;
53 var uy = y + 1 > height - 1 ? height - 1 : y + 1;
54 var lx = x - 1 < 0 ? 0 : x - 1;
55 var ux = x + 1 > width - 1 ? width - 1 : x + 1;
58 var origin = [ 0, 0, data[ ( y * width + x ) * 4 ] / 255 * depth ];
59 points.push( [ - 1, 0, data[ ( y * width + lx ) * 4 ] / 255 * depth ] );
60 points.push( [ - 1, - 1, data[ ( ly * width + lx ) * 4 ] / 255 * depth ] );
61 points.push( [ 0, - 1, data[ ( ly * width + x ) * 4 ] / 255 * depth ] );
62 points.push( [ 1, - 1, data[ ( ly * width + ux ) * 4 ] / 255 * depth ] );
63 points.push( [ 1, 0, data[ ( y * width + ux ) * 4 ] / 255 * depth ] );
64 points.push( [ 1, 1, data[ ( uy * width + ux ) * 4 ] / 255 * depth ] );
65 points.push( [ 0, 1, data[ ( uy * width + x ) * 4 ] / 255 * depth ] );
66 points.push( [ - 1, 1, data[ ( uy * width + lx ) * 4 ] / 255 * depth ] );
69 var num_points = points.length;
71 for ( var i = 0; i < num_points; i ++ ) {
74 var v2 = points[ ( i + 1 ) % num_points ];
75 v1 = subtract( v1, origin );
76 v2 = subtract( v2, origin );
77 normals.push( normalize( cross( v1, v2 ) ) );
81 var normal = [ 0, 0, 0 ];
83 for ( var i = 0; i < normals.length; i ++ ) {
85 normal[ 0 ] += normals[ i ][ 0 ];
86 normal[ 1 ] += normals[ i ][ 1 ];
87 normal[ 2 ] += normals[ i ][ 2 ];
91 normal[ 0 ] /= normals.length;
92 normal[ 1 ] /= normals.length;
93 normal[ 2 ] /= normals.length;
95 var idx = ( y * width + x ) * 4;
97 output[ idx ] = ( ( normal[ 0 ] + 1.0 ) / 2.0 * 255 ) | 0;
98 output[ idx + 1 ] = ( ( normal[ 1 ] + 1.0 ) / 2.0 * 255 ) | 0;
99 output[ idx + 2 ] = ( normal[ 2 ] * 255 ) | 0;
100 output[ idx + 3 ] = 255;
106 context.putImageData( imageData, 0, 0 );
112 generateDataTexture: function ( width, height, color ) {
114 var size = width * height;
115 var data = new Uint8Array( 3 * size );
117 var r = Math.floor( color.r * 255 );
118 var g = Math.floor( color.g * 255 );
119 var b = Math.floor( color.b * 255 );
121 for ( var i = 0; i < size; i ++ ) {
124 data[ i * 3 + 1 ] = g;
125 data[ i * 3 + 2 ] = b;
129 var texture = new THREE.DataTexture( data, width, height, THREE.RGBFormat );
130 texture.needsUpdate = true;