0.0001f) { uv *= scale; } if (noiseType == 0) { simplex = fractalNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, float2(distortionU, distortionV), distortionRatio); if (simplex < 0.0f) simplex = 0.0f; } if (noiseType == 1) { if (distortionRatio > 0.0001f) { uv.x += distortionU * distortionRatio; uv.y += (distortionV + 0.2) * distortionRatio; } simplex = cellNoise(uv, amplitude, frequency); } if (noiseType == 2) { simplex = ridgedNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, float2(distortionU, distortionV), distortionRatio); } simplex += threshold; if (gamma != 1.0f) simplex = pow(simplex, (1.0f / gamma)); if (simplex < 0.0f) simplex = 0.0f; return float3(simplex, simplex, simplex); } ]]> 0.0001) { uv *= scale; } if (noiseType == 0) { simplex = fractalNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, float2(distortionU, distortionV), distortionRatio); if (simplex < 0.0f) simplex = 0.0f; } if (noiseType == 1) { if (distortionRatio > 0.0001) { uv.x += distortionU * distortionRatio; uv.y += (distortionV + 0.2) * distortionRatio; } simplex = cellNoise(uv, amplitude, frequency); } if (noiseType == 2) { simplex = ridgedNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, float2(distortionU, distortionV), distortionRatio); } simplex += threshold; if (gamma != 1.0f) simplex = pow(simplex, (1.0f / gamma)); if (simplex < 0.0f) simplex = 0.0f; return float3(simplex, simplex, simplex); } ]]> -1.0 range // x = ( sqrt( 0.5 )/sqrt( 0.75 ) ) * 0.5 // NF = 1.0 / ( x * ( ( 0.5 – x*x ) ^ 4 ) * 2.0 ) // http://briansharpe.wordpress.com/2012/01/13/simplex-noise/#comment-36 const float FINAL_NORMALIZATION = 99.204334582718712976990005025589; // evaluate the surflet, sum and return vec3 m = vec3( v0.x, v12.xz ) * vec3( v0.x, v12.xz ) + vec3( v0.y, v12.yw ) * vec3( v0.y, v12.yw ); m = max(0.5 - m, 0.0); // The 0.5 here is SIMPLEX_TRI_HEIGHT^2 m = m*m; return dot(m*m, grad_results) * FINAL_NORMALIZATION; } vec4 Cellular_weight_samples( vec4 samples ) { samples = samples * 2.0 - 1.0; return (samples * samples * samples) - sign(samples); // cubic (even more variance) } float SimplexCellular2D( vec2 P ) { // simplex math based off Stefan Gustavson's and Ian McEwan's work at... // http://github.com/ashima/webgl-noise // simplex math constants const float SKEWFACTOR = 0.36602540378443864676372317075294; // 0.5*(sqrt(3.0)-1.0) const float UNSKEWFACTOR = 0.21132486540518711774542560974902; // (3.0-sqrt(3.0))/6.0 const float SIMPLEX_TRI_HEIGHT = 0.70710678118654752440084436210485; // sqrt( 0.5 ) height of simplex triangle. const float INV_SIMPLEX_TRI_HEIGHT = 1.4142135623730950488016887242097; // 1.0 / sqrt( 0.5 ) const vec3 SIMPLEX_POINTS = vec3( 1.0-UNSKEWFACTOR, -UNSKEWFACTOR, 1.0-2.0*UNSKEWFACTOR ) * INV_SIMPLEX_TRI_HEIGHT; // vertex info for simplex triangle // establish our grid cell. P *= SIMPLEX_TRI_HEIGHT; // scale space so we can have an approx feature size of 1.0 ( optional ) vec2 Pi = floor( P + dot( P, vec2( SKEWFACTOR ) ) ); // calculate the hash. // ( various hashing methods listed in order of speed ) vec4 hash_x, hash_y; FAST32_hash_2D( Pi, hash_x, hash_y ); //SGPP_hash_2D( Pi, hash_x, hash_y ); // push hash values to extremes of jitter window const float JITTER_WINDOW = ( 0.10566243270259355887271280487451 * INV_SIMPLEX_TRI_HEIGHT ); // this will guarentee no artifacts. hash_x = Cellular_weight_samples( hash_x ) * JITTER_WINDOW; hash_y = Cellular_weight_samples( hash_y ) * JITTER_WINDOW; // calculate sq distance to closest point vec2 p0 = ( ( Pi - dot( Pi, vec2( UNSKEWFACTOR ) ) ) - P ) * INV_SIMPLEX_TRI_HEIGHT; hash_x += p0.xxxx; hash_y += p0.yyyy; hash_x.yzw += SIMPLEX_POINTS.xyz; hash_y.yzw += SIMPLEX_POINTS.yxz; vec4 distsq = hash_x*hash_x + hash_y*hash_y; vec2 tmp = min( distsq.xy, distsq.zw ); return min( tmp.x, tmp.y ); } float fractalNoise( vec2 uv, float amplitude, float ratio, int octaves, float frequency, float frequencyRatio, vec2 distortion, float distortionRatio) { float noise = 0.0f; float simplex = 0.0f; distortion *= distortionRatio; for (int i=0; i < octaves+1; i++) { noise = SimplexPerlin2D(uv+distortion) * pow(frequency, -amplitude*i); simplex += amplitude * noise; float tmp = uv.x; uv.x = uv.y * frequency - 0.02f; uv.y = tmp * frequency + 0.3f; amplitude *= ratio; frequency *= frequencyRatio; distortion *= distortionRatio; } simplex = 0.5f * simplex + 0.5f; return simplex; } float cellNoise( vec2 uv, float amplitude, float frequency) { float noise = SimplexCellular2D(uv*frequency); float simplex = amplitude * noise; return simplex; } float ridgedNoise( vec2 uv, float amplitude, float ratio, int octaves, float frequency, float frequencyRatio, vec2 distortion, float distortionRatio) { float simplex, signal, weight, offset; simplex = 1.0; offset = 1.0; signal = offset - abs(SimplexPerlin2D(uv)); signal *= signal; simplex = signal; weight = 1.0; distortion *= distortionRatio; for(int i=1; i 0.0001) { uv *= scale; } if (noiseType == 0) { simplex = fractalNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, vec2(distortionU, distortionV), distortionRatio); if (simplex < 0.0f) simplex = 0.0f; } if (noiseType == 1) { if (distortionRatio > 0.0001) { uv[0] += distortionU * distortionRatio; uv[1] += (distortionV + 0.2) * distortionRatio; } simplex = cellNoise(uv, amplitude, frequency); } if (noiseType == 2) { simplex = ridgedNoise(uv, amplitude, ratio, octaves, frequency, frequencyRatio, vec2(distortionU, distortionV), distortionRatio); } simplex += threshold; if (gamma != 1.0f) { simplex = pow(simplex, (1.0f / gamma)); } if (simplex < 0.0f) { simplex = 0.0f; } return vec3(simplex, simplex, simplex); } ]]>