// -*-C++-*- #version 120 // written by Thorsten Renk, May 2014 // based on ALS terrain shader // 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 sampler2D mix_texture; uniform sampler2D grain_texture; uniform sampler2D gradient_texture; varying float steepness; varying vec2 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 air_pollution; uniform float grain_strength; uniform float intrinsic_wetness; uniform float overlay_fraction; uniform float overlay_scale; uniform float rotation_scale; uniform float distortion_factor; uniform float uv_xoffset; uniform float uv_yoffset; uniform float landing_light1_offset; uniform float landing_light2_offset; uniform float landing_light3_offset; uniform float dust_resistance; uniform float WindE; uniform float WindN; uniform float osg_SimulationTime; uniform int quality_level; uniform int tquality_level; uniform int wind_effects; uniform int cloud_shadow_flag; uniform int rotation_flag; uniform int use_searchlight; uniform int use_landing_light; uniform int use_alt_landing_light; const float EarthRadius = 5800000.0; const float terminator_width = 200000.0; float alt; float eShade; float yprime_alt; float mie_angle; float shadow_func (in float x, in float y, in float noise, in float dist); float Noise2D(in vec2 coord, in float wavelength); float Noise3D(in vec3 coord, in float wavelength); float VoronoiNoise2D(in vec2 coord, in float wavelength, in float xrand, in float yrand); float SlopeLines2D(in vec2 coord, in vec2 gradDir, in float wavelength, in float steepness); float fog_func (in float targ, in float alt); float rayleigh_in_func(in float dist, in float air_pollution, in float avisibility, in float eye_alt, in float vertex_alt); float alt_factor(in float eye_alt, in float vertex_alt); float light_distance_fading(in float dist); float fog_backscatter(in float avisibility); vec3 rayleigh_out_shift(in vec3 color, in float outscatter); vec3 get_hazeColor(in float light_arg); vec3 searchlight(); vec3 landing_light(in float offset, in float offsetv); vec3 filter_combined (in vec3 color) ; // 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); } 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(0.55, 0.67, 0.88); // 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; // Wind motion of the overlay noise simulating movement of vegetation and loose debris vec2 windPos; if (wind_effects > 1) { float windSpeed = length(vec2 (WindE,WindN)) /3.0480; // interfering sine wave wind pattern float sineTerm = sin(0.35 * windSpeed * osg_SimulationTime + 0.05 * (rawPos.x + rawPos.y)); sineTerm = sineTerm + sin(0.3 * windSpeed * osg_SimulationTime + 0.04 * (rawPos.x + rawPos.y)); sineTerm = sineTerm + sin(0.22 * windSpeed * osg_SimulationTime + 0.05 * (rawPos.x + rawPos.y)); sineTerm = sineTerm/3.0; // non-linear amplification to simulate gusts sineTerm = sineTerm * sineTerm;//smoothstep(0.2, 1.0, sineTerm); // wind starts moving dust and leaves at around 8 m/s float timeArg = 0.01 * osg_SimulationTime * windSpeed * smoothstep(8.0, 15.0, windSpeed); timeArg = timeArg + 0.02 * sineTerm; windPos = vec2 (rawPos.x + WindN * timeArg, rawPos.y + WindE * timeArg); } else { windPos = rawPos.xy; } // 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(windPos.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); // tiling noise float vnoise_overlay = VoronoiNoise2D(rawPos.xy, overlay_scale, distortion_factor, distortion_factor); float vnoise_rotation = VoronoiNoise2D(rawPos.xy, rotation_scale, distortion_factor, distortion_factor); // slope noise float slopenoise_50m = SlopeLines2D(rawPos, grad_dir, 50.0, steepness); float slopenoise_100m = SlopeLines2D(rawPos, grad_dir, 100.0, steepness); float snownoise_25m = mix(noise_25m, slopenoise_50m, clamp(3.0*(1.0-steepness),0.0,1.0)); float snownoise_50m = mix(noise_50m, slopenoise_100m, clamp(3.0*(1.0-steepness),0.0,1.0)); // get the texels float distortion_factor = 1.0; vec2 stprime; int flag = 1; int mix_flag = 1; float noise_term; float snow_alpha; float angle = vnoise_rotation * 2.0 * 3.1415; if (rotation_flag ==2) { if (vnoise_rotation < 0.25) {angle = 0.5 * 3.1415926;} else if (vnoise_rotation < 0.5) {angle = 3.1415926;} else if (vnoise_rotation < 0.75) {angle = 1.5 * 3.1415926;} else {angle = 0.0;} } if (rotation_flag > 0) { stprime = vec2 (cos(angle)*gl_TexCoord[0].s + sin(angle)*gl_TexCoord[0].t, -sin(angle)*gl_TexCoord[0].s + cos(angle)*gl_TexCoord[0].t); } else {stprime = gl_TexCoord[0].st;} stprime+= vec2 (uv_xoffset, uv_yoffset); texel = texture2D(texture, stprime); 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); // 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 * (snownoise_50m -0.5) * detail_fade(50.0, view_angle, 0.5*dist) ; noise_term = noise_term + 0.2 * (snownoise_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, stprime * 1.3); if (mix_texel.a <0.1) {mix_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); if (vnoise_overlay > overlay_fraction) {mix_factor = 0.0;} else {mix_factor = 1.0;} texel = mix(texel, mix_texel, mix_factor); local_autumn_factor = texel.a; } // 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; } // 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))); } // slope line overlay texel.rgb = texel.rgb * (1.0 - 0.12 * slopenoise_50m - 0.08 * slopenoise_100m); //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 ) - 0.03*slopenoise_100m,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); // 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; 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); if (NdotL > 0.0) { 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);} color += diffuse_term * NdotL; NdotHV = max(dot(n, halfVector), 0.0); if (gl_FrontMaterial.shininess > 0.0) specular.rgb = ((gl_FrontMaterial.specular.rgb * 0.1 + (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); vec3 secondary_light = vec3 (0.0,0.0,0.0); if (use_searchlight == 1) { secondary_light += searchlight(); } if (use_landing_light == 1) { secondary_light += landing_light(landing_light1_offset, landing_light3_offset); } if (use_alt_landing_light == 1) { secondary_light += landing_light(landing_light2_offset, landing_light3_offset); } color.rgb +=secondary_light * light_distance_fading(dist); fragColor = color * texel + specular; float lightArg = (terminator-yprime_alt)/100000.0; vec3 hazeColor = get_hazeColor(lightArg); // Rayleigh color shift due to out-scattering float rayleigh_length = 0.5 * avisibility * (2.5 - 1.9 * air_pollution)/alt_factor(eye_alt, eye_alt+relPos.z); float outscatter = 1.0-exp(-dist/rayleigh_length); fragColor.rgb = rayleigh_out_shift(fragColor.rgb,outscatter); // Rayleigh color shift due to in-scattering float rShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt + 420000.0); //float lightIntensity = length(diffuse_term.rgb)/1.73 * rShade; float lightIntensity = length(hazeColor * effective_scattering) * rShade; vec3 rayleighColor = vec3 (0.17, 0.52, 0.87) * lightIntensity; float rayleighStrength = rayleigh_in_func(dist, air_pollution, avisibility/max(lightIntensity,0.05), eye_alt, eye_alt + relPos.z); fragColor.rgb = mix(fragColor.rgb, rayleighColor,rayleighStrength); // here comes the terrain haze model float delta_z = hazeLayerAltitude - eye_alt; float mvisibility = min(visibility,avisibility); if (dist > 0.04 * mvisibility) { 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,mvisibility) * 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; } } // blur of the haze layer edge float blur_thickness = 50.0; float cphi = dot(vec3(0.0, 1.0, 0.0), relPos)/dist; float ctlayer = delta_z/dist-0.01 + 0.02 * Noise2D(vec2(cphi,1.0),0.1) -0.01; float ctblur = 0.035 ; float blur_dist; if (abs(delta_z) < 400.0) { blur_dist = dist * (1.0-smoothstep(0.0,300.0,-delta_z)) * smoothstep(-400.0,-200.0, -delta_z); blur_dist = blur_dist * smoothstep(ctlayer-4.0*ctblur, ctlayer-ctblur, ct) * (1.0-smoothstep(ctlayer+0.5*ctblur, ctlayer+ctblur, ct)); distance_in_layer = max(distance_in_layer, blur_dist); } // 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, alt); // 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; // now dim the light for haze eShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt); // 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)); } // 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); hazeColor.rgb *= eqColorFactor * eShade; hazeColor.rgb = max(hazeColor.rgb, minLight.rgb); fragColor.rgb = mix(hazeColor + secondary_light * fog_backscatter(mvisibility), fragColor.rgb,transmission); } fragColor.rgb = filter_combined(fragColor.rgb); gl_FragColor = fragColor; }