620 lines
20 KiB
C++
620 lines
20 KiB
C++
// -*-C++-*-
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#version 120
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// adapted by James Hester 2018, based on rock-ALS.frag
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// by Thorsten Renk.
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// Ambient term comes in gl_Color.rgb.
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varying vec4 diffuse_term;
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varying vec3 normal;
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varying vec3 relPos;
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varying vec2 rawPos;
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varying vec3 worldPos;
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varying vec3 ecViewdir;
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varying float steepness;
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varying vec2 grad_dir;
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uniform float visibility;
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uniform float avisibility;
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uniform float scattering;
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uniform float terminator;
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uniform float terrain_alt;
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uniform float hazeLayerAltitude;
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uniform float overcast;
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uniform float eye_alt;
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uniform float dust_cover_factor;
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uniform float lichen_cover_factor;
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uniform float wetness;
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uniform float fogstructure;
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uniform float cloud_self_shading;
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uniform float contrast;
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uniform float air_pollution;
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uniform float intrinsic_wetness;
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uniform float transition_model;
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uniform float overlay_bias;
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uniform float crack_depth;
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uniform float crack_pattern_stretch;
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uniform float grain_fade_power;
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uniform float rock_brightness;
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uniform float overlay_alpha;
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uniform float dust_resistance;
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uniform float slopeline_strength;
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uniform float landing_light1_offset;
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uniform float landing_light2_offset;
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uniform float landing_light3_offset;
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uniform float osg_SimulationTime;
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uniform vec3 base_color;
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uniform vec3 overlay_color;
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uniform int wind_effects;
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uniform int cloud_shadow_flag;
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uniform int rock_strata;
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uniform int use_searchlight;
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uniform int use_landing_light;
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uniform int use_alt_landing_light;
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const float EarthRadius = 5800000.0;
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const float terminator_width = 200000.0;
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float alt;
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float eShade;
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float yprime_alt;
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float mie_angle;
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float shadow_func (in float x, in float y, in float noise, in float dist);
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float Noise2D(in vec2 coord, in float wavelength);
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float Noise3D(in vec3 coord, in float wavelength);
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float VoronoiNoise2D(in vec2 coord, in float wavelength, in float xrand, in float yrand);
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float SlopeLines2D(in vec2 coord, in vec2 gradDir, in float wavelength, in float steepness);
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float Strata3D(in vec3 coord, in float wavelength, in float variation);
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float fog_func (in float targ, in float alt);
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float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt);
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float alt_factor(in float eye_alt, in float vertex_alt);
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float light_distance_fading(in float dist);
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float fog_backscatter(in float avisibility);
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vec3 rayleigh_out_shift(in vec3 color, in float outscatter);
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vec3 get_hazeColor(in float light_arg);
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vec3 searchlight();
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vec3 landing_light(in float offset, in float offsetv);
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vec3 filter_combined (in vec3 color) ;
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float light_func (in float x, in float a, in float b, in float c, in float d, in float e)
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{
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x = x - 0.5;
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// use the asymptotics to shorten computations
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if (x > 30.0) {return e;}
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if (x < -15.0) {return 0.0;}
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return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d));
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}
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// a fade function for procedural scales which are smaller than a pixel
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float detail_fade (in float scale, in float angle, in float dist)
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{
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float fade_dist = 2000.0 * scale * angle/max(pow(steepness,4.0), 0.1);
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return 1.0 - smoothstep(0.5 * fade_dist, fade_dist, dist);
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}
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void main()
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{
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yprime_alt = diffuse_term.a;
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//diffuse_term.a = 1.0;
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mie_angle = gl_Color.a;
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float effective_scattering = min(scattering, cloud_self_shading);
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// distance to fragment
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float dist = length(relPos);
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// horizontal distance using texture coordinate
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float horiz_coord = gl_TexCoord[0].s * 1000.0;
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// angle of view vector with horizon
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float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist;
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// float altitude of fragment above base of cliff
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float cliff_altitude = gl_TexCoord[0].t * 1000.0;
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vec3 shadedFogColor = vec3(0.55, 0.67, 0.88);
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// this is taken from default.frag
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vec3 n;
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float NdotL, NdotHV, fogFactor;
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vec4 color = gl_Color;
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color.a = 1.0;
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vec3 lightDir = gl_LightSource[0].position.xyz;
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vec3 halfVector = normalize(normalize(lightDir) + normalize(ecViewdir));
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vec4 texel;
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vec4 detail_texel;
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vec4 mix_texel;
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vec4 grain_texel;
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vec4 dot_texel;
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vec4 gradient_texel;
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vec4 foam_texel;
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vec4 fragColor;
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vec4 specular = vec4(0.0);
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float intensity;
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// Perlin noise, distance along cliff in texture coordinate instead of x,y
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float noise_100m = Noise2D(vec2(horiz_coord,cliff_altitude),100.0);
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float noise_50m = Noise2D(vec2(horiz_coord,cliff_altitude), 50.0);
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float noise_25m = Noise2D(vec2(horiz_coord,cliff_altitude), 25.0);
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float noise_10m = Noise2D(vec2(horiz_coord,cliff_altitude), 10.0);
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float noise_5m = Noise2D(vec2(horiz_coord,cliff_altitude) ,5.0);
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float noise_2m = Noise2D(vec2(horiz_coord,cliff_altitude) ,2.0);
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float noise_1m = Noise2D(vec2(horiz_coord,cliff_altitude) ,1.0);
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float noise_05m = Noise2D(vec2(horiz_coord,cliff_altitude),0.5);
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float noise_02m = Noise2D(vec2(horiz_coord,cliff_altitude),0.2);
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float noise_01m = Noise2D(vec2(horiz_coord,cliff_altitude), 0.1);
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float noisegrad_10m;
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float noisegrad_5m;
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float noisegrad_2m;
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float noisegrad_1m;
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float noisegrad_05m;
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float noisegrad_02m;
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float noisegrad_01m;
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float noise_250m = Noise3D(worldPos.xyz,250.0);
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float noise_500m = Noise3D(worldPos.xyz, 500.0);
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float noise_1500m = Noise3D(worldPos.xyz, 1500.0);
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float noise_2000m = Noise3D(worldPos.xyz, 2000.0);
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// dot noise
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float dotnoise_2m = 0.0;
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float dotnoise_10m = 0.0;
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float dotnoise_15m = 0.0;
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float dotnoisegrad_10m;
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// slope noise
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float slopenoise_50m = SlopeLines2D(rawPos, grad_dir, 50.0, steepness);
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float slopenoise_100m = SlopeLines2D(rawPos, grad_dir, 100.0, steepness);
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// get the texels
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float noise_term;
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float local_autumn_factor;
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// we need to fade procedural structures when they get smaller than a single pixel, for this we need
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// to know under what angle we see the surface
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float view_angle = abs(dot(normalize(normal), normalize(ecViewdir)));
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// strata noise
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float stratnoise_50m;
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float stratnoise_10m;
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if (rock_strata==1)
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{
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stratnoise_50m = Strata3D(vec3 (rawPos.x, rawPos.y, cliff_altitude), 50.0, 0.2);
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stratnoise_10m = Strata3D(vec3 (rawPos.x, rawPos.y, cliff_altitude), 10.0, 0.2);
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stratnoise_50m = mix(stratnoise_50m, 1.0, smoothstep(0.8,0.9, steepness));
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stratnoise_10m = mix(stratnoise_10m, 1.0, smoothstep(0.8,0.9, steepness));
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texel *= (0.4 + 0.4 * stratnoise_50m + 0.2 * stratnoise_10m);
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}
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// procedural rock texture generation
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texel.rgb = base_color;
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// use powers of Perlin noise to generate the base pattern
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float grainy_noise;
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float fade_norm;
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float gfp = grain_fade_power;
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float gfptmp;
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//grainy_noise = (0.5 * (1.0-slopenoise_100m) + 0.5 *noise_50m) + gfp * (0.5 * slopenoise_50m + 0.5 * noise_25m);
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grainy_noise = (0.5 *noise_50m) + gfp * ( 0.5 * noise_25m);
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fade_norm = 1.0+gfp;
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gfptmp = gfp * gfp;
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grainy_noise += noise_10m * gfptmp * detail_fade(10.0, view_angle, dist) ;
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fade_norm += gfptmp * detail_fade(10.0, view_angle, dist) ;
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gfptmp = gfptmp * gfp;
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grainy_noise += noise_5m * gfptmp * detail_fade(5.0, view_angle, dist) ;
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fade_norm += gfptmp * detail_fade(5.0, view_angle, dist) ;
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gfptmp = gfptmp * gfp;
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grainy_noise += noise_2m * gfptmp * detail_fade(2.0, view_angle, dist) ;
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fade_norm += gfptmp * detail_fade(2.0, view_angle, dist) ;
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gfptmp = gfptmp * gfp;
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grainy_noise += noise_1m * gfptmp * detail_fade(1.0, view_angle, dist) ;
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fade_norm += gfptmp * detail_fade(1.0, view_angle, dist) ;
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gfptmp = gfptmp * gfp;
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grainy_noise += noise_05m * gfptmp * detail_fade(0.5, view_angle, dist) ;
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fade_norm += gfptmp * detail_fade(0.5, view_angle, dist) ;
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grainy_noise = grainy_noise/fade_norm;
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grainy_noise = smoothstep(-0.2, 1.2, grainy_noise);
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// generate the crack pattern from isovalue lines of stretched Perlin noise
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float cnoise_500m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 500.0);
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float cnoise_250m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 250.0);
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float cnoise_100m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 100.0);
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float cnoise_50m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 50.0);
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float cnoise_25m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 25.0);
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float cnoise_10m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 10.0);
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float cnoise_5m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 5.0);
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float cnoise_2m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 2.0);
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float cnoise_1m = Noise2D(vec2(horiz_coord+10.0, crack_pattern_stretch * cliff_altitude), 1.0);
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float crack_noise;
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float crack_factor;
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float crack_size;
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float scrack_noise;
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float scrack_size;
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crack_noise = cnoise_500m + 0.65 * cnoise_250m + 0.42 * cnoise_100m * detail_fade(50.0, view_angle, dist) ;
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crack_noise = crack_noise + 0.27 * cnoise_50m * detail_fade(25.0, view_angle, dist) ;
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crack_noise = crack_noise + 0.17 * cnoise_25m * detail_fade(10.0, view_angle, dist) ;
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crack_noise = crack_noise + 0.11 * cnoise_10m * detail_fade(5.0, view_angle, dist) ;
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crack_noise = 0.381 * crack_noise;
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scrack_noise = cnoise_10m + 0.65 * cnoise_5m * detail_fade(5.0, view_angle, dist);
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scrack_noise = scrack_noise + 0.3 * cnoise_2m + 0.1 * cnoise_1m * detail_fade(1.0, view_angle, dist);
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scrack_noise = 0.48 * scrack_noise;
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crack_size = 0.02 +0.00001 * dist;
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crack_factor = smoothstep(0.5-crack_size,0.50,crack_noise) * (1.0-smoothstep(0.51,0.51+crack_size,crack_noise));
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//crack_factor = step(0.5-0.2*crack_size,crack_noise) * (1.0-step(0.5+0.2*crack_size,crack_noise));
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crack_size *= 0.5;
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crack_factor += smoothstep(0.42,0.42+crack_size,crack_noise) * (1.0-smoothstep(0.43,0.43+crack_size,crack_noise));
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scrack_size = crack_size * 4.0;
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crack_factor += 0.75 * smoothstep(0.5-scrack_size,0.50,scrack_noise) * (1.0-smoothstep(0.51,0.51+scrack_size,scrack_noise))* (1.0- smoothstep(250.0,1000.0,dist));
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crack_factor = crack_factor * min(1.0,0.03/crack_size);
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// distribution of overlay color
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float overlay_noise;
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float overlay_factor;
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overlay_noise = 0.381 * (noise_50m + 0.65 * noise_25m + 0.42 * noise_10m + 0.27 * noise_5m + 0.17 * noise_2m + 0.11 * noise_1m);
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overlay_noise = overlay_noise + 0.1 * (smoothstep(0.8,0.9, steepness));
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overlay_factor = smoothstep(0.7, 0.72, overlay_noise + overlay_bias) + (1.0 - smoothstep(0.2, 0.22, overlay_noise - overlay_bias));
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// merge the noise components
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//grainy_noise = grainy_noise * (1.0-crack_depth * crack_factor) + 0.5 * crack_depth * crack_factor;
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texel.rgb = ((1.0 - contrast) + contrast * grainy_noise ) * texel.rgb;
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texel.rgb = mix(texel.rgb, overlay_color.rgb,overlay_alpha * overlay_factor);
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texel.rgb = texel.rgb * ((1.0-crack_depth) +crack_depth*(1.0-crack_factor * (0.5 + 0.5 * noise_50m) ));
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texel.rgb = texel.rgb * rock_brightness;
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texel.rgb = texel.rgb * (1.0 + 0.4 * (noise_01m-0.5) * detail_fade(0.1, view_angle, dist)) ;
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const vec4 dust_color = vec4 (0.76, 0.65, 0.45, 1.0);
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const vec4 lichen_color = vec4 (0.17, 0.20, 0.06, 1.0);
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// mix vegetation
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float gradient_factor = smoothstep(0.5, 1.0, steepness);
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texel = mix(texel, lichen_color, gradient_factor * (0.4 * lichen_cover_factor + 0.8 * lichen_cover_factor * 0.5 * (noise_10m + (1.0 - noise_5m))) );
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// mix dust
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texel = mix(texel, dust_color, clamp(0.5 * dust_cover_factor *dust_resistance + 3.0 * dust_cover_factor * dust_resistance *(((noise_1500m - 0.5) * 0.125)+0.125 ), 0.0, 1.0) );
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// get distribution of water when terrain is wet
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float combined_wetness = min(1.0, wetness + intrinsic_wetness);
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float water_threshold1;
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float water_threshold2;
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float water_factor =0.0;
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if ((dist < 5000.0) && (combined_wetness>0.0))
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{
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water_threshold1 = 1.0-0.5* combined_wetness;
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water_threshold2 = 1.0 - 0.3 * combined_wetness;
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water_factor = smoothstep(water_threshold1, water_threshold2 , (0.3 * (2.0 * (1.0-noise_10m) + (1.0 -noise_5m)) * (1.0 - smoothstep(2000.0, 5000.0, dist))) - 5.0 * (1.0 -steepness));
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}
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// darken wet terrain
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texel.rgb = texel.rgb * (1.0 - 0.6 * combined_wetness);
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// light computations
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vec4 light_specular = gl_LightSource[0].specular;
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// If gl_Color.a == 0, this is a back-facing polygon and the
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// normal should be reversed.
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//n = (2.0 * gl_Color.a - 1.0) * normal;
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n = normal;
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n = normalize(n);
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NdotL = dot(n, lightDir);
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noisegrad_10m = (noise_10m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),10.0))/0.05;
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noisegrad_5m = (noise_5m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),5.0))/0.05;
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noisegrad_2m = (noise_2m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),2.0))/0.05;
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noisegrad_1m = (noise_1m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),1.0))/0.05;
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noisegrad_05m = (noise_05m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),0.5))/0.05;
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dotnoisegrad_10m = 0.0;
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float fresnel;
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if (NdotL > 0.0) {
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if (cloud_shadow_flag == 1) {NdotL = NdotL * shadow_func(relPos.x, relPos.y, 0.3 * noise_250m + 0.5 * noise_500m+0.2 * noise_1500m, dist);}
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color += diffuse_term * NdotL;
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NdotHV = max(dot(n, halfVector), 0.0);
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fresnel = 1.0 + 5.0 * (1.0-smoothstep(0.0,0.2, dot(normalize(ecViewdir),n)));
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//if (gl_FrontMaterial.shininess > 0.0)
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specular.rgb = ((gl_FrontMaterial.specular.rgb * 0.1 + (water_factor * vec3 (1.0, 1.0, 1.0)))
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* light_specular.rgb
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* pow(NdotHV, max(gl_FrontMaterial.shininess,4.0) + (20.0 * water_factor)));
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}
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color.a = 1.0;//diffuse_term.a;
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// This shouldn't be necessary, but our lighting becomes very
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// saturated. Clamping the color before modulating by the texture
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// is closer to what the OpenGL fixed function pipeline does.
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color = clamp(color, 0.0, 1.0);
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vec3 secondary_light = vec3 (0.0,0.0,0.0);
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if (use_searchlight == 1)
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{
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secondary_light += searchlight();
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}
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if (use_landing_light == 1)
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{
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secondary_light += landing_light(landing_light1_offset, landing_light3_offset);
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}
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if (use_alt_landing_light == 1)
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{
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secondary_light += landing_light(landing_light2_offset, landing_light3_offset);
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}
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color.rgb +=secondary_light * light_distance_fading(dist);
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fragColor = color * texel + specular;
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float lightArg = (terminator-yprime_alt)/100000.0;
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vec3 hazeColor = get_hazeColor(lightArg);
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// Rayleigh color shift due to out-scattering
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float rayleigh_length = 0.5 * avisibility * (2.5 - 1.9 * air_pollution)/alt_factor(eye_alt, eye_alt+relPos.z);
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float outscatter = 1.0-exp(-dist/rayleigh_length);
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fragColor.rgb = rayleigh_out_shift(fragColor.rgb,outscatter);
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// Rayleigh color shift due to in-scattering
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float rShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt + 420000.0);
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float lightIntensity = length(hazeColor * effective_scattering) * rShade;
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vec3 rayleighColor = vec3 (0.17, 0.52, 0.87) * lightIntensity;
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float rayleighStrength = rayleigh_in_func(dist, air_pollution, avisibility/max(lightIntensity,0.05), eye_alt, eye_alt + relPos.z);
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fragColor.rgb = mix(fragColor.rgb, rayleighColor,rayleighStrength);
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// here comes the terrain haze model
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float delta_z = hazeLayerAltitude - eye_alt;
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float mvisibility = min(visibility,avisibility);
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if (dist > 0.04 * mvisibility)
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{
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alt = eye_alt;
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float transmission;
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float vAltitude;
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float delta_zv;
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float H;
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float distance_in_layer;
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float transmission_arg;
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// we solve the geometry what part of the light path is attenuated normally and what is through the haze layer
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if (delta_z > 0.0) // we're inside the layer
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{
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if (ct < 0.0) // we look down
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{
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distance_in_layer = dist;
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vAltitude = min(distance_in_layer,mvisibility) * ct;
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delta_zv = delta_z - vAltitude;
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}
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else // we may look through upper layer edge
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{
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H = dist * ct;
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if (H > delta_z) {distance_in_layer = dist/H * delta_z;}
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else {distance_in_layer = dist;}
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vAltitude = min(distance_in_layer,visibility) * ct;
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delta_zv = delta_z - vAltitude;
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}
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}
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else // we see the layer from above, delta_z < 0.0
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{
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H = dist * -ct;
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if (H < (-delta_z)) // we don't see into the layer at all, aloft visibility is the only fading
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{
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distance_in_layer = 0.0;
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delta_zv = 0.0;
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}
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else
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{
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vAltitude = H + delta_z;
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distance_in_layer = vAltitude/H * dist;
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vAltitude = min(distance_in_layer,visibility) * (-ct);
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delta_zv = vAltitude;
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}
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}
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// blur of the haze layer edge
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float blur_thickness = 50.0;
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float cphi = dot(vec3(0.0, 1.0, 0.0), relPos)/dist;
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float ctlayer = delta_z/dist-0.01 + 0.02 * Noise2D(vec2(cphi,1.0),0.1) -0.01;
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float ctblur = 0.035 ;
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float blur_dist;
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if (abs(delta_z) < 400.0)
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{
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blur_dist = dist * (1.0-smoothstep(0.0,300.0,-delta_z)) * smoothstep(-400.0,-200.0, -delta_z);
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blur_dist = blur_dist * smoothstep(ctlayer-4.0*ctblur, ctlayer-ctblur, ct) * (1.0-smoothstep(ctlayer+0.5*ctblur, ctlayer+ctblur, ct));
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distance_in_layer = max(distance_in_layer, blur_dist);
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}
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// ground haze cannot be thinner than aloft visibility in the model,
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// so we need to use aloft visibility otherwise
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transmission_arg = (dist-distance_in_layer)/avisibility;
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float eqColorFactor;
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if (visibility < avisibility)
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{
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transmission_arg = transmission_arg + (distance_in_layer/(1.0 * visibility + 1.0 * visibility * fogstructure * 0.06 * (noise_1500m + noise_2000m -1.0) ));
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// this combines the Weber-Fechner intensity
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eqColorFactor = 1.0 - 0.1 * delta_zv/visibility - (1.0 - effective_scattering);
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}
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else
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{
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transmission_arg = transmission_arg + (distance_in_layer/(1.0 * avisibility + 1.0 * avisibility * fogstructure * 0.06 * (noise_1500m + noise_2000m - 1.0) ));
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// this combines the Weber-Fechner intensity
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eqColorFactor = 1.0 - 0.1 * delta_zv/avisibility - (1.0 - effective_scattering);
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}
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transmission = fog_func(transmission_arg, alt);
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// there's always residual intensity, we should never be driven to zero
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if (eqColorFactor < 0.2) eqColorFactor = 0.2;
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// now dim the light for haze
|
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eShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt);
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// Mie-like factor
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if (lightArg < 10.0)
|
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{
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intensity = length(hazeColor);
|
|
float mie_magnitude = 0.5 * smoothstep(350000.0, 150000.0, terminator-sqrt(2.0 * EarthRadius * terrain_alt));
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hazeColor = intensity * ((1.0 - mie_magnitude) + mie_magnitude * mie_angle) * normalize(mix(hazeColor, vec3 (0.5, 0.58, 0.65), mie_magnitude * (0.5 - 0.5 * mie_angle)) );
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}
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intensity = length(hazeColor);
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if (intensity > 0.0) // this needs to be a condition, because otherwise hazeColor doesn't come out correctly
|
|
{
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// high altitude desaturation of the haze color
|
|
hazeColor = intensity * normalize (mix(hazeColor, intensity * vec3 (1.0,1.0,1.0), 0.7* smoothstep(5000.0, 50000.0, alt)));
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// blue hue of haze
|
|
hazeColor.x = hazeColor.x * 0.83;
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|
hazeColor.y = hazeColor.y * 0.9;
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// additional blue in indirect light
|
|
float fade_out = max(0.65 - 0.3 *overcast, 0.45);
|
|
intensity = length(hazeColor);
|
|
hazeColor = intensity * normalize(mix(hazeColor, 1.5* shadedFogColor, 1.0 -smoothstep(0.25, fade_out,eShade) ));
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// change haze color to blue hue for strong fogging
|
|
hazeColor = intensity * normalize(mix(hazeColor, shadedFogColor, (1.0-smoothstep(0.5,0.9,eqColorFactor))));
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// reduce haze intensity when looking at shaded surfaces, only in terminator region
|
|
float shadow = mix( min(1.0 + dot(n,lightDir),1.0), 1.0, 1.0-smoothstep(0.1, 0.4, transmission));
|
|
hazeColor = mix(shadow * hazeColor, hazeColor, 0.3 + 0.7* smoothstep(250000.0, 400000.0, terminator));
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}
|
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// don't let the light fade out too rapidly
|
|
lightArg = (terminator + 200000.0)/100000.0;
|
|
float minLightIntensity = min(0.2,0.16 * lightArg + 0.5);
|
|
vec3 minLight = minLightIntensity * vec3 (0.2, 0.3, 0.4);
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hazeColor.rgb *= eqColorFactor * eShade;
|
|
hazeColor.rgb = max(hazeColor.rgb, minLight.rgb);
|
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|
fragColor.rgb = mix(hazeColor + secondary_light * fog_backscatter(mvisibility), fragColor.rgb,transmission);
|
|
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|
}
|
|
|
|
fragColor.rgb = filter_combined(fragColor.rgb);
|
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|
|
gl_FragColor = fragColor;
|
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|
}
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