// -*- mode: C; -*- // Licence: GPL v2 // Author: Frederic Bouvier. // Adapted from the paper by F. Policarpo et al. : Real-time Relief Mapping on Arbitrary Polygonal Surfaces // Adapted from the paper and sources by M. Drobot in GPU Pro : Quadtree Displacement Mapping with Height Blending #version 120 #extension GL_ATI_shader_texture_lod : enable #extension GL_ARB_shader_texture_lod : enable #define TEXTURE_MIP_LEVELS 10 #define TEXTURE_PIX_COUNT 1024 //pow(2,TEXTURE_MIP_LEVELS) #define BINARY_SEARCH_COUNT 10 #define BILINEAR_SMOOTH_FACTOR 2.0 varying vec3 worldPos; varying vec4 ecPosition; varying vec3 VNormal; varying vec3 VTangent; varying vec4 constantColor; varying vec3 light_diffuse; varying vec3 relPos; varying float yprime_alt; varying float mie_angle; uniform sampler2D BaseTex; uniform sampler2D NormalTex; uniform sampler2D QDMTex; uniform float depth_factor; uniform float tile_size; uniform float quality_level; 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 mysnowlevel; uniform float dust_cover_factor; uniform float wetness; uniform float fogstructure; uniform float cloud_self_shading; uniform float air_pollution; uniform float landing_light1_offset; uniform float landing_light2_offset; uniform vec3 night_color; uniform bool random_buildings; uniform int cloud_shadow_flag; uniform int use_searchlight; uniform int use_landing_light; uniform int use_alt_landing_light; uniform int gquality_level; uniform int tquality_level; const float scale = 1.0; int linear_search_steps = 10; int GlobalIterationCount = 0; int gIterationCap = 64; const float EarthRadius = 5800000.0; const float terminator_width = 200000.0; float alt; float eShade; 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 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); void QDM(inout vec3 p, inout vec3 v) { const int MAX_LEVEL = TEXTURE_MIP_LEVELS; const float NODE_COUNT = TEXTURE_PIX_COUNT; const float TEXEL_SPAN_HALF = 1.0 / NODE_COUNT / 2.0; float fDeltaNC = TEXEL_SPAN_HALF * depth_factor; vec3 p2 = p; float level = MAX_LEVEL; vec2 dirSign = (sign(v.xy) + 1.0) * 0.5; GlobalIterationCount = 0; float d = 0.0; while (level >= 0.0 && GlobalIterationCount < gIterationCap) { vec4 uv = vec4(p2.xyz, level); d = texture2DLod(QDMTex, uv.xy, uv.w).w; if (d > p2.z) { //predictive point of ray traversal vec3 tmpP2 = p + v * d; //current node count float nodeCount = pow(2.0, (MAX_LEVEL - level)); //current and predictive node ID vec4 nodeID = floor(vec4(p2.xy, tmpP2.xy)*nodeCount); //check if we are crossing the current cell if (nodeID.x != nodeID.z || nodeID.y != nodeID.w) { //calculate distance to nearest bound vec2 a = p2.xy - p.xy; vec2 p3 = (nodeID.xy + dirSign) / nodeCount; vec2 b = p3.xy - p.xy; vec2 dNC = (b.xy * p2.z) / a.xy; //take the nearest cell d = min(d,min(dNC.x, dNC.y))+fDeltaNC; level++; } p2 = p + v * d; } level--; GlobalIterationCount++; } // // Manual Bilinear filtering // float rayLength = length(p2.xy - p.xy) + fDeltaNC; float dA = p2.z * (rayLength - BILINEAR_SMOOTH_FACTOR * TEXEL_SPAN_HALF) / rayLength; float dB = p2.z * (rayLength + BILINEAR_SMOOTH_FACTOR * TEXEL_SPAN_HALF) / rayLength; vec4 p2a = vec4(p + v * dA, 0.0); vec4 p2b = vec4(p + v * dB, 0.0); dA = texture2DLod(NormalTex, p2a.xy, p2a.w).w; dB = texture2DLod(NormalTex, p2b.xy, p2b.w).w; dA = abs(p2a.z - dA); dB = abs(p2b.z - dB); p2 = mix(p2a.xyz, p2b.xyz, dA / (dA + dB)); p = p2; } float ray_intersect_QDM(vec2 dp, vec2 ds) { vec3 p = vec3( dp, 0.0 ); vec3 v = vec3( ds, 1.0 ); QDM( p, v ); return p.z; } float ray_intersect_relief(vec2 dp, vec2 ds) { float size = 1.0 / float(linear_search_steps); float depth = 0.0; float best_depth = 1.0; for(int i = 0; i < linear_search_steps - 1; ++i) { depth += size; float t = step(0.95, texture2D(NormalTex, dp + ds * depth).a); if(best_depth > 0.996) if(depth >= t) best_depth = depth; } depth = best_depth; const int binary_search_steps = 5; for(int i = 0; i < binary_search_steps; ++i) { size *= 0.5; float t = step(0.95, texture2D(NormalTex, dp + ds * depth).a); if(depth >= t) { best_depth = depth; depth -= 2.0 * size; } depth += size; } return(best_depth); } float ray_intersect(vec2 dp, vec2 ds) { if ( random_buildings ) return 0.0; else if ( quality_level >= 4.0 ) return ray_intersect_QDM( dp, ds ); else return ray_intersect_relief( dp, ds ); } void main (void) { if ( quality_level >= 3.0 ) { linear_search_steps = 20; } float depthfactor = depth_factor; if ( random_buildings ) depthfactor = 0.0; vec3 shadedFogColor = vec3(0.65, 0.67, 0.78); float effective_scattering = min(scattering, cloud_self_shading); vec3 normal = normalize(VNormal); vec3 tangent = normalize(VTangent); //vec3 binormal = normalize(VBinormal); vec3 binormal = normalize(cross(normal, tangent)); vec3 ecPos3 = ecPosition.xyz / ecPosition.w; vec3 V = normalize(ecPos3); vec3 s = vec3(dot(V, tangent), dot(V, binormal), dot(normal, -V)); vec2 ds = s.xy * depthfactor / s.z; vec2 dp = gl_TexCoord[0].st - ds; float d = ray_intersect(dp, ds); vec2 uv = dp + ds * d; vec3 N = texture2D(NormalTex, uv).xyz * 2.0 - 1.0; float emis = N.z; N.z = sqrt(1.0 - min(1.0,dot(N.xy, N.xy))); float Nz = N.z; N = normalize(N.x * tangent + N.y * binormal + N.z * normal); vec3 l = gl_LightSource[0].position.xyz; vec3 diffuse = gl_Color.rgb * max(0.0, dot(N, l)); float dist = length(relPos); if (cloud_shadow_flag == 1) {diffuse = diffuse * shadow_func(relPos.x, relPos.y, 1.0, dist);} float shadow_factor = 1.0; // Shadow if ( quality_level >= 2.0 ) { dp += ds * d; vec3 sl = normalize( vec3( dot( l, tangent ), dot( l, binormal ), dot( -l, normal ) ) ); ds = sl.xy * depthfactor / sl.z; dp -= ds * d; float dl = ray_intersect(dp, ds); if ( dl < d - 0.05 ) shadow_factor = dot( constantColor.xyz, vec3( 1.0, 1.0, 1.0 ) ) * 0.25; } // end shadow vec4 ambient_light = constantColor + vec4 (light_diffuse,1.0) * vec4(diffuse, 1.0); float reflectance = ambient_light.r * 0.3 + ambient_light.g * 0.59 + ambient_light.b * 0.11; if ( shadow_factor < 1.0 ) ambient_light = constantColor + vec4(light_diffuse,1.0) * shadow_factor * vec4(diffuse, 1.0); float emission_factor = (1.0 - smoothstep(0.15, 0.25, reflectance)) * emis; vec4 tc = texture2D(BaseTex, uv); emission_factor *= 0.5*pow(tc.r+0.8*tc.g+0.2*tc.b, 2.0) -0.2; ambient_light += (emission_factor * vec4(night_color, 0.0)); vec4 finalColor = texture2D(BaseTex, uv); // texel postprocessing by shader effects // dust effect vec4 dust_color; float noise_1500m = Noise3D(worldPos.xyz,1500.0); float noise_2000m = Noise3D(worldPos.xyz,2000.0); if (gquality_level > 2) { // mix dust dust_color = vec4 (0.76, 0.71, 0.56, 1.0); finalColor = mix(finalColor, dust_color, clamp(0.5 * dust_cover_factor + 3.0 * dust_cover_factor * (((noise_1500m - 0.5) * 0.125)+0.125 ),0.0, 1.0) ); } // darken wet terrain finalColor.rgb = finalColor.rgb * (1.0 - 0.6 * wetness); 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); } if (use_alt_landing_light == 1) { secondary_light += landing_light(landing_light2_offset); } ambient_light = clamp(ambient_light,0.0,1.0); ambient_light.rgb +=secondary_light * light_distance_fading(dist); finalColor *= ambient_light; vec4 p = vec4( ecPos3 + tile_size * V * (d-1.0) * depthfactor / s.z, 1.0 ); float lightArg = (terminator-yprime_alt)/100000.0; vec3 hazeColor = get_hazeColor(lightArg); // Rayleigh color shifts if ((gquality_level > 5) && (tquality_level > 5)) { 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); finalColor.rgb = rayleigh_out_shift(finalColor.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(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); finalColor.rgb = mix(finalColor.rgb, rayleighColor,rayleighStrength); } // here comes the terrain haze model float delta_z = hazeLayerAltitude - eye_alt; if (dist > 0.04 * min(visibility,avisibility)) { alt = eye_alt; float transmission; float vAltitude; float delta_zv; float H; float distance_in_layer; float transmission_arg; float intensity; vec3 lightDir = gl_LightSource[0].position.xyz; // angle with horizon float ct = dot(vec3(0.0, 0.0, 1.0), relPos)/dist; // 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 (gquality_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 (gquality_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; // 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 { // Mie-like factor if (lightArg < 10.0) { 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)) ); } // 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(VNormal,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 *= eqColorFactor * eShade; hazeColor.rgb = max(hazeColor.rgb, minLight.rgb); finalColor.rgb = mix( hazeColor +secondary_light * fog_backscatter(avisibility), finalColor.rgb,transmission); } gl_FragColor = finalColor; if (dot(normal,-V) > 0.1) { vec4 iproj = gl_ProjectionMatrix * p; iproj /= iproj.w; gl_FragDepth = (iproj.z+1.0)/2.0; } else { gl_FragDepth = gl_FragCoord.z; } }