// -*-C++-*- // written by Thorsten Renk, Oct 2011, based on default.frag // Ambient term comes in gl_Color.rgb. varying vec4 diffuse_term; varying vec3 normal; varying vec3 relPos; varying vec2 rawPos; varying vec3 worldPos; varying vec3 ecViewdir; uniform sampler2D texture; uniform sampler3D NoiseTex; uniform sampler2D snow_texture; uniform sampler2D detail_texture; uniform sampler2D mix_texture; uniform sampler2D grain_texture; uniform sampler2D dot_texture; uniform sampler2D gradient_texture; //varying float yprime_alt; //varying float mie_angle; varying float steepness; varying float grad_dir; uniform float visibility; uniform float avisibility; uniform float scattering; uniform float terminator; uniform float terrain_alt; uniform float hazeLayerAltitude; uniform float overcast; uniform float eye_alt; uniform float snowlevel; uniform float dust_cover_factor; uniform float lichen_cover_factor; uniform float wetness; uniform float fogstructure; uniform float snow_thickness_factor; uniform float cloud_self_shading; uniform float season; uniform float windspeed; uniform float grain_strength; uniform float intrinsic_wetness; uniform float transition_model; uniform float hires_overlay_bias; uniform float dot_density; uniform float dot_size; uniform float dust_resistance; uniform float osg_SimulationTime; uniform int quality_level; uniform int tquality_level; const float EarthRadius = 5800000.0; const float terminator_width = 200000.0; float alt; float eShade; float yprime_alt; float mie_angle; float rand2D(in vec2 co){ return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453); } float rand3D(in vec3 co){ return fract(sin(dot(co.xyz ,vec3(12.9898,78.233,144.7272))) * 43758.5453); } float cosine_interpolate(in float a, in float b, in float x) { float ft = x * 3.1415927; float f = (1.0 - cos(ft)) * .5; return a*(1.0-f) + b*f; } float simple_interpolate(in float a, in float b, in float x) { return a + smoothstep(0.0,1.0,x) * (b-a); } float interpolatedNoise2D(in float x, in float y) { float integer_x = x - fract(x); float fractional_x = x - integer_x; float integer_y = y - fract(y); float fractional_y = y - integer_y; float v1 = rand2D(vec2(integer_x, integer_y)); float v2 = rand2D(vec2(integer_x+1.0, integer_y)); float v3 = rand2D(vec2(integer_x, integer_y+1.0)); float v4 = rand2D(vec2(integer_x+1.0, integer_y +1.0)); float i1 = simple_interpolate(v1 , v2 , fractional_x); float i2 = simple_interpolate(v3 , v4 , fractional_x); return simple_interpolate(i1 , i2 , fractional_y); } float interpolatedNoise3D(in float x, in float y, in float z) { float integer_x = x - fract(x); float fractional_x = x - integer_x; float integer_y = y - fract(y); float fractional_y = y - integer_y; float integer_z = z - fract(z); float fractional_z = z - integer_z; float v1 = rand3D(vec3(integer_x, integer_y, integer_z)); float v2 = rand3D(vec3(integer_x+1.0, integer_y, integer_z)); float v3 = rand3D(vec3(integer_x, integer_y+1.0, integer_z)); float v4 = rand3D(vec3(integer_x+1.0, integer_y +1.0, integer_z)); float v5 = rand3D(vec3(integer_x, integer_y, integer_z+1.0)); float v6 = rand3D(vec3(integer_x+1.0, integer_y, integer_z+1.0)); float v7 = rand3D(vec3(integer_x, integer_y+1.0, integer_z+1.0)); float v8 = rand3D(vec3(integer_x+1.0, integer_y +1.0, integer_z+1.0)); float i1 = simple_interpolate(v1,v5, fractional_z); float i2 = simple_interpolate(v2,v6, fractional_z); float i3 = simple_interpolate(v3,v7, fractional_z); float i4 = simple_interpolate(v4,v8, fractional_z); float ii1 = simple_interpolate(i1,i2,fractional_x); float ii2 = simple_interpolate(i3,i4,fractional_x); return simple_interpolate(ii1 , ii2 , fractional_y); } float Noise2D(in vec2 coord, in float wavelength) { return interpolatedNoise2D(coord.x/wavelength, coord.y/wavelength); } float Noise3D(in vec3 coord, in float wavelength) { return interpolatedNoise3D(coord.x/wavelength, coord.y/wavelength, coord.z/wavelength); } float dotNoise2D(in float x, in float y, in float fractionalMaxDotSize) { float integer_x = x - fract(x); float fractional_x = x - integer_x; float integer_y = y - fract(y); float fractional_y = y - integer_y; if (rand2D(vec2(integer_x+1.0, integer_y +1.0)) > dot_density) {return 0.0;} float xoffset = (rand2D(vec2(integer_x, integer_y)) -0.5); float yoffset = (rand2D(vec2(integer_x+1.0, integer_y)) - 0.5); float dotSize = 0.5 * fractionalMaxDotSize * max(0.25,rand2D(vec2(integer_x, integer_y+1.0))); vec2 truePos = vec2 (0.5 + xoffset * (1.0 - 2.0 * dotSize) , 0.5 + yoffset * (1.0 -2.0 * dotSize)); float distance = length(truePos - vec2(fractional_x, fractional_y)); return 1.0 - smoothstep (0.3 * dotSize, 1.0* dotSize, distance); } float DotNoise2D(in vec2 coord, in float wavelength, in float fractionalMaxDotSize) { return dotNoise2D(coord.x/wavelength, coord.y/wavelength, fractionalMaxDotSize); } float light_func (in float x, in float a, in float b, in float c, in float d, in float e) { x = x - 0.5; // use the asymptotics to shorten computations if (x > 30.0) {return e;} if (x < -15.0) {return 0.0;} return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d)); } // a fade function for procedural scales which are smaller than a pixel float detail_fade (in float scale, in float angle, in float dist) { float fade_dist = 2000.0 * scale * angle/max(pow(steepness,4.0), 0.1); return 1.0 - smoothstep(0.5 * fade_dist, fade_dist, dist); } // this determines how light is attenuated in the distance // physically this should be exp(-arg) but for technical reasons we use a sharper cutoff // for distance > visibility float fog_func (in float targ) { float fade_mix; // for large altitude > 30 km, we switch to some component of quadratic distance fading to // create the illusion of improved visibility range targ = 1.25 * targ * smoothstep(0.04,0.06,targ); // need to sync with the distance to which terrain is drawn if (alt < 30000.0) {return exp(-targ - targ * targ * targ * targ);} else if (alt < 50000.0) { fade_mix = (alt - 30000.0)/20000.0; return fade_mix * exp(-targ*targ - pow(targ,4.0)) + (1.0 - fade_mix) * exp(-targ - pow(targ,4.0)); } else { return exp(- targ * targ - pow(targ,4.0)); } } void main() { yprime_alt = diffuse_term.a; //diffuse_term.a = 1.0; mie_angle = gl_Color.a; float effective_scattering = min(scattering, cloud_self_shading); // distance to fragment float dist = length(relPos); // angle of view vector with horizon float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist; // float altitude of fragment above sea level float msl_altitude = (relPos.z + eye_alt); vec3 shadedFogColor = vec3(0.65, 0.67, 0.78); // this is taken from default.frag vec3 n; float NdotL, NdotHV, fogFactor; vec4 color = gl_Color; color.a = 1.0; vec3 lightDir = gl_LightSource[0].position.xyz; vec3 halfVector = normalize(normalize(lightDir) + normalize(ecViewdir)); vec4 texel; vec4 snow_texel; vec4 detail_texel; vec4 mix_texel; vec4 grain_texel; vec4 dot_texel; vec4 gradient_texel; vec4 foam_texel; vec4 fragColor; vec4 specular = vec4(0.0); float intensity; // get noise at different wavelengths // used: 5m, 5m gradient, 10m, 10m gradient: heightmap of the closeup terrain, 10m also snow // 50m: detail texel // 250m: detail texel // 500m: distortion and overlay // 1500m: overlay, detail, dust, fog // 2000m: overlay, detail, snow, fog // Perlin noise float noise_10m = Noise2D(rawPos.xy, 10.0); float noise_5m = Noise2D(rawPos.xy ,5.0); float noise_2m = Noise2D(rawPos.xy ,2.0); float noise_1m = Noise2D(rawPos.xy ,1.0); float noise_01m = Noise2D(rawPos.xy, 0.1); float noisegrad_10m; float noisegrad_5m; float noisegrad_2m; float noisegrad_1m; float noise_25m = Noise2D(rawPos.xy, 25.0); float noise_50m = Noise2D(rawPos.xy, 50.0); float noise_250m = Noise3D(worldPos.xyz,250.0); float noise_500m = Noise3D(worldPos.xyz, 500.0); float noise_1500m = Noise3D(worldPos.xyz, 1500.0); float noise_2000m = Noise3D(worldPos.xyz, 2000.0); // dot noise float dotnoise_2m = DotNoise2D(rawPos.xy, 2.0 * dot_size,0.5); float dotnoise_10m = DotNoise2D(rawPos.xy, 10.0 * dot_size, 0.5); float dotnoise_15m = DotNoise2D(rawPos.xy, 15.0 * dot_size, 0.33); float dotnoisegrad_10m; // get the texels float distortion_factor = 1.0; vec2 stprime; int flag = 1; int mix_flag = 1; float noise_term; float snow_alpha; texel = texture2D(texture, gl_TexCoord[0].st); float local_autumn_factor = texel.a; grain_texel = texture2D(grain_texture, gl_TexCoord[0].st * 25.0); gradient_texel = texture2D(gradient_texture, gl_TexCoord[0].st * 4.0); stprime = gl_TexCoord[0].st * 80.0; stprime = stprime + normalize(relPos).xy * 0.01 * (dotnoise_10m + dotnoise_15m); dot_texel = texture2D(dot_texture, vec2 (stprime.y, stprime.x) ); // we need to fade procedural structures when they get smaller than a single pixel, for this we need // to know under what angle we see the surface float view_angle = abs(dot(normalize(normal), normalize(ecViewdir))); float sfactor = sqrt(2.0 * (1.0-steepness)/0.03) + abs(ct)/0.15; // the snow texel is generated procedurally if (msl_altitude +500.0 > snowlevel) { snow_texel = vec4 (0.95, 0.95, 0.95, 1.0) * (0.9 + 0.1* noise_500m + 0.1* (1.0 - noise_10m) ); snow_texel.r = snow_texel.r * (0.9 + 0.05 * (noise_10m + noise_5m)); snow_texel.g = snow_texel.g * (0.9 + 0.05 * (noise_10m + noise_5m)); snow_texel.a = 1.0; noise_term = 0.1 * (noise_500m-0.5) ; noise_term = noise_term + 0.2 * (noise_50m -0.5) * detail_fade(50.0, view_angle, 0.5*dist) ; noise_term = noise_term + 0.2 * (noise_25m -0.5) * detail_fade(25.0, view_angle, 0.5*dist) ; noise_term = noise_term + 0.3 * (noise_10m -0.5) * detail_fade(10.0, view_angle, 0.8*dist) ; noise_term = noise_term + 0.3 * (noise_5m - 0.5) * detail_fade(5.0, view_angle, dist); noise_term = noise_term + 0.15 * (noise_2m -0.5) * detail_fade(2.0, view_angle, dist); noise_term = noise_term + 0.08 * (noise_1m -0.5) * detail_fade(1.0, view_angle, dist); snow_texel.a = snow_texel.a * 0.2+0.8* smoothstep(0.2,0.8, 0.3 +noise_term + snow_thickness_factor +0.0001*(msl_altitude -snowlevel) ); } // the mixture/gradient texture mix_texel = texture2D(mix_texture, gl_TexCoord[0].st * 1.3); if (mix_texel.a <0.1) {mix_flag = 0;} // the hires overlay texture is loaded with parallax mapping stprime = vec2 (0.86*gl_TexCoord[0].s + 0.5*gl_TexCoord[0].t, 0.5*gl_TexCoord[0].s - 0.86*gl_TexCoord[0].t); distortion_factor = 0.97 + 0.06 * noise_500m; stprime = stprime * distortion_factor * 15.0; stprime = stprime + normalize(relPos).xy * 0.022 * (noise_10m + 0.5 * noise_5m +0.25 * noise_2m - 0.875 ); detail_texel = texture2D(detail_texture, stprime); if (detail_texel.a <0.1) {flag = 0;} // texture preparation according to detail level // mix in hires texture patches float dist_fact; float nSum; float mix_factor; // first the second texture overlay // transition model 0: random patch overlay without any gradient information // transition model 1: only gradient-driven transitions, no randomness if (mix_flag == 1) { nSum = 0.18 * (2.0 * noise_2000m + 2.0 * noise_1500m + noise_500m); nSum = mix(nSum, 0.5, max(0.0, 2.0 * (transition_model - 0.5))); nSum = nSum + 0.4 * (1.0 -smoothstep(0.9,0.95, abs(steepness)+ 0.05 * (noise_50m - 0.5))) * min(1.0, 2.0 * transition_model); mix_factor = smoothstep(0.5, 0.54, nSum); texel = mix(texel, mix_texel, mix_factor); local_autumn_factor = texel.a; } // then the detail texture overlay mix_factor = 0.0; if (dist < 40000.0) { if (flag == 1) { dist_fact = 0.1 * smoothstep(15000.0,40000.0, dist) - 0.03 * (1.0 - smoothstep(500.0,5000.0, dist)); nSum = ((1.0 -noise_2000m) + noise_1500m + 2.0 * noise_250m +noise_50m)/5.0; nSum = nSum - 0.08 * (1.0 -smoothstep(0.9,0.95, abs(steepness))); mix_factor = smoothstep(0.47, 0.54, nSum +hires_overlay_bias- dist_fact); if (mix_factor > 0.8) {mix_factor = 0.8;} texel = mix(texel, detail_texel,mix_factor); } } // rock for very steep gradients if (gradient_texel.a > 0.0) { texel = mix(texel, gradient_texel, 1.0 - smoothstep(0.75,0.8,abs(steepness)+ 0.00002* msl_altitude + 0.05 * (noise_50m - 0.5))); local_autumn_factor = texel.a; } // the dot vegetation texture overlay texel.rgb = mix(texel.rgb, dot_texel.rgb, dot_texel.a * (dotnoise_10m + dotnoise_15m) * detail_fade(1.0 * (dot_size * (1.0 +0.1*dot_size)), view_angle,dist)); texel.rgb = mix(texel.rgb, dot_texel.rgb, dot_texel.a * dotnoise_2m * detail_fade(0.1 * dot_size, view_angle,dist)); // then the grain texture overlay texel.rgb = mix(texel.rgb, grain_texel.rgb, grain_strength * grain_texel.a * (1.0 - mix_factor) * (1.0-smoothstep(2000.0,5000.0, dist))); // for really hires, add procedural noise overlay texel.rgb = texel.rgb * (1.0 + 0.4 * (noise_01m-0.5) * detail_fade(0.1, view_angle, dist)) ; // autumn colors float autumn_factor = season * 2.0 * (1.0 - local_autumn_factor) ; texel.r = min(1.0, (1.0 + 2.5 * autumn_factor) * texel.r); texel.g = texel.g; texel.b = max(0.0, (1.0 - 4.0 * autumn_factor) * texel.b); if (local_autumn_factor < 1.0) { intensity = length(texel.rgb) * (1.0 - 0.5 * smoothstep(1.1,2.0,season)); texel.rgb = intensity * normalize(mix(texel.rgb, vec3(0.23,0.17,0.08), smoothstep(1.1,2.0, season))); } //const vec4 dust_color = vec4 (0.76, 0.71, 0.56, 1.0); const vec4 dust_color = vec4 (0.76, 0.65, 0.45, 1.0); const vec4 lichen_color = vec4 (0.17, 0.20, 0.06, 1.0); // mix vegetation float gradient_factor = smoothstep(0.5, 1.0, steepness); 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))) ); // mix dust 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) ); // mix snow float snow_mix_factor = 0.0; if (msl_altitude +500.0 > snowlevel) { snow_alpha = smoothstep(0.75, 0.85, abs(steepness)); snow_mix_factor = snow_texel.a* smoothstep(snowlevel, snowlevel+200.0, snow_alpha * msl_altitude+ (noise_2000m + 0.1 * noise_10m -0.55) *400.0); texel = mix(texel, snow_texel, snow_mix_factor); } // get distribution of water when terrain is wet float combined_wetness = min(1.0, wetness + intrinsic_wetness); float water_threshold1; float water_threshold2; float water_factor =0.0; if ((dist < 5000.0)&& (quality_level > 3) && (combined_wetness>0.0)) { water_threshold1 = 1.0-0.5* combined_wetness; water_threshold2 = 1.0 - 0.3 * combined_wetness; 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)); } // darken wet terrain texel.rgb = texel.rgb * (1.0 - 0.6 * combined_wetness); // surf - terrain is too bad... /* foam_texel.rgb =vec3 (1.0, 1.0, 1.0); foam_texel.rg = 0.7 * foam_texel.rg +0.3 * noise_2m * foam_texel.rg; float surf_strength = 1.0 + windspeed/5.0; float surf_sine = sin(osg_SimulationTime+5.0*noise_25m); float surf_steepcorr = 1.0 -smoothstep(0.99,1.01,abs(steepness)); float surf_alt = (relPos.z+eye_alt ) - 20.0 * surf_steepcorr ;//+ noise_10m * surf_steepcorr texel.rgb = mix(foam_texel.rgb, texel.rgb, smoothstep((0.3 +0.3*surf_strength+ surf_sine) * surf_steepcorr-20.0, (0.3+ surf_strength + surf_sine) * surf_steepcorr-19.0, surf_alt)); */ // light computations vec4 light_specular = gl_LightSource[0].specular; // If gl_Color.a == 0, this is a back-facing polygon and the // normal should be reversed. //n = (2.0 * gl_Color.a - 1.0) * normal; n = normal;//vec3 (nvec.x, nvec.y, sqrt(1.0 -pow(nvec.x,2.0) - pow(nvec.y,2.0) )); n = normalize(n); NdotL = dot(n, lightDir); noisegrad_10m = (noise_10m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),10.0))/0.05; noisegrad_5m = (noise_5m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),5.0))/0.05; noisegrad_2m = (noise_2m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),2.0))/0.05; noisegrad_1m = (noise_1m - Noise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),1.0))/0.05; dotnoisegrad_10m = (dotnoise_10m - DotNoise2D(rawPos.xy+ 0.05 * normalize(lightDir.xy),10.0 * dot_size,0.5))/0.05; NdotL = NdotL + (noisegrad_10m * detail_fade(10.0, view_angle,dist) + 0.5* noisegrad_5m * detail_fade(5.0, view_angle,dist)) * mix_factor/0.8; NdotL = NdotL + 0.15 * noisegrad_2m * mix_factor/0.8 * detail_fade(2.0,view_angle,dist); NdotL = NdotL + 0.1 * noisegrad_2m * detail_fade(2.0,view_angle,dist); NdotL = NdotL + 0.05 * noisegrad_1m * detail_fade(1.0, view_angle,dist); NdotL = NdotL + (1.0-snow_mix_factor) * 0.3* dot_texel.a * (0.5* dotnoisegrad_10m * detail_fade(1.0 * dot_size, view_angle, dist) +0.5 * dotnoisegrad_10m * noise_01m * detail_fade(0.1, view_angle, dist)) ; if (NdotL > 0.0) { color += diffuse_term * NdotL; NdotHV = max(dot(n, halfVector), 0.0); if (gl_FrontMaterial.shininess > 0.0) specular.rgb = ((gl_FrontMaterial.specular.rgb + (water_factor * vec3 (1.0, 1.0, 1.0))) * light_specular.rgb * pow(NdotHV, gl_FrontMaterial.shininess + (20.0 * water_factor))); } color.a = 1.0;//diffuse_term.a; // This shouldn't be necessary, but our lighting becomes very // saturated. Clamping the color before modulating by the texture // is closer to what the OpenGL fixed function pipeline does. color = clamp(color, 0.0, 1.0); fragColor = color * texel + specular; // here comes the terrain haze model float delta_z = hazeLayerAltitude - eye_alt; if (dist > 0.04 * min(visibility,avisibility)) //if ((gl_FragCoord.y > ylimit) || (gl_FragCoord.x < zlimit1) || (gl_FragCoord.x > zlimit2)) //if (dist > 40.0) { alt = eye_alt; float transmission; float vAltitude; float delta_zv; float H; float distance_in_layer; float transmission_arg; // we solve the geometry what part of the light path is attenuated normally and what is through the haze layer if (delta_z > 0.0) // we're inside the layer { if (ct < 0.0) // we look down { distance_in_layer = dist; vAltitude = min(distance_in_layer,min(visibility, avisibility)) * ct; delta_zv = delta_z - vAltitude; } else // we may look through upper layer edge { H = dist * ct; if (H > delta_z) {distance_in_layer = dist/H * delta_z;} else {distance_in_layer = dist;} vAltitude = min(distance_in_layer,visibility) * ct; delta_zv = delta_z - vAltitude; } } else // we see the layer from above, delta_z < 0.0 { H = dist * -ct; if (H < (-delta_z)) // we don't see into the layer at all, aloft visibility is the only fading { distance_in_layer = 0.0; delta_zv = 0.0; } else { vAltitude = H + delta_z; distance_in_layer = vAltitude/H * dist; vAltitude = min(distance_in_layer,visibility) * (-ct); delta_zv = vAltitude; } } // ground haze cannot be thinner than aloft visibility in the model, // so we need to use aloft visibility otherwise transmission_arg = (dist-distance_in_layer)/avisibility; float eqColorFactor; if (visibility < avisibility) { if (quality_level > 3) { transmission_arg = transmission_arg + (distance_in_layer/(1.0 * visibility + 1.0 * visibility * fogstructure * 0.06 * (noise_1500m + noise_2000m -1.0) )); } else { transmission_arg = transmission_arg + (distance_in_layer/visibility); } // this combines the Weber-Fechner intensity eqColorFactor = 1.0 - 0.1 * delta_zv/visibility - (1.0 - effective_scattering); } else { if (quality_level > 3) { transmission_arg = transmission_arg + (distance_in_layer/(1.0 * avisibility + 1.0 * avisibility * fogstructure * 0.06 * (noise_1500m + noise_2000m - 1.0) )); } else { transmission_arg = transmission_arg + (distance_in_layer/avisibility); } // this combines the Weber-Fechner intensity eqColorFactor = 1.0 - 0.1 * delta_zv/avisibility - (1.0 - effective_scattering); } transmission = fog_func(transmission_arg); // there's always residual intensity, we should never be driven to zero if (eqColorFactor < 0.2) eqColorFactor = 0.2; float lightArg = (terminator-yprime_alt)/100000.0; vec3 hazeColor; hazeColor.b = light_func(lightArg, 1.330e-05, 0.264, 2.527, 1.08e-05, 1.0); hazeColor.g = light_func(lightArg, 3.931e-06, 0.264, 3.827, 7.93e-06, 1.0); hazeColor.r = light_func(lightArg, 8.305e-06, 0.161, 3.827, 3.04e-05, 1.0); // now dim the light for haze eShade = 0.9 * smoothstep(terminator_width+ terminator, -terminator_width + terminator, yprime_alt) + 0.1; // Mie-like factor if (lightArg < 10.0) { intensity = length(hazeColor); float mie_magnitude = 0.5 * smoothstep(350000.0, 150000.0, terminator-sqrt(2.0 * EarthRadius * terrain_alt)); 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)) ); } intensity = length(hazeColor); if (intensity > 0.0) // this needs to be a condition, because otherwise hazeColor doesn't come out correctly { // 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))); // blue hue of haze hazeColor.x = hazeColor.x * 0.83; hazeColor.y = hazeColor.y * 0.9; // 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) )); // change haze color to blue hue for strong fogging hazeColor = intensity * normalize(mix(hazeColor, shadedFogColor, (1.0-smoothstep(0.5,0.9,eqColorFactor)))); // 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)); } fragColor.rgb = mix(eqColorFactor * hazeColor * eShade , fragColor.rgb,transmission); gl_FragColor = fragColor; } else // if dist < threshold no fogging at all { gl_FragColor = fragColor; } }