diff --git a/Effects/model-default.eff b/Effects/model-default.eff index ac822605a..70e4db331 100644 --- a/Effects/model-default.eff +++ b/Effects/model-default.eff @@ -103,10 +103,10 @@ vertex-program-two-side - Shaders/generic-ALS-base.vert - Shaders/model-ALS-base.frag - Shaders/hazes.frag - Shaders/secondary_lights.frag + Shaders/generic-ALS-base.vert + Shaders/model-ALS-base.frag + Shaders/hazes.frag + Shaders/secondary_lights.frag visibility diff --git a/Effects/space.eff b/Effects/space.eff new file mode 100644 index 000000000..936d34900 --- /dev/null +++ b/Effects/space.eff @@ -0,0 +1,18 @@ + + + + Effects/space + Effects/model-default + + + + + Shaders/space-ALS-base.vert + Shaders/space-ALS-base.frag + Shaders/hazes.frag + Shaders/secondary_lights.frag + + + + + diff --git a/Shaders/space-ALS-base.frag b/Shaders/space-ALS-base.frag new file mode 100644 index 000000000..b54cf83e5 --- /dev/null +++ b/Shaders/space-ALS-base.frag @@ -0,0 +1,330 @@ +// -*-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; + + +uniform sampler2D texture; + + +varying float yprime_alt; +varying float mie_angle; + + +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 cloud_self_shading; +uniform float air_pollution; +uniform float landing_light1_offset; +uniform float landing_light2_offset; + +uniform int quality_level; +uniform int tquality_level; +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 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); + + +float luminance(vec3 color) +{ + return dot(vec3(0.212671, 0.715160, 0.072169), color); +} + + +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)); +} + +// 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 + + + + +void main() +{ + + 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; + vec3 lightDir = gl_LightSource[0].position.xyz; + vec3 halfVector = gl_LightSource[0].halfVector.xyz; + vec4 texel; + vec4 fragColor; + vec4 specular = vec4(0.0); + float intensity; + + float effective_scattering = min(scattering, cloud_self_shading); + + eShade = 1.0 - 0.9 * smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt); + vec4 light_specular = gl_LightSource[0].specular * (eShade - 0.1); + + // 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 = normalize(n); + + NdotL = dot(n, lightDir); + 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 + * light_specular.rgb + * pow(NdotHV, gl_FrontMaterial.shininess)); + } + + //vec3 up = (gl_ModelViewMatrix * vec4(0.0,0.0,1.0,0.0)).xyz; + + //vec3 sky_blue = vec3 (0.17, 0.52, 0.87); + + //NdotL = dot(n, -up); + //if (NdotL > 0.0) + //{ + //color.rgb += sky_blue * NdotL; + //} + + color.a = 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); + + float dist = length(relPos); + vec3 secondary_light = vec3 (0.0,0.0,0.0); + + if ((quality_level > 5) && (tquality_level > 5)) + { + 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); + } + if (dist > 2.0) // we don't want to light the cockpit... + {color.rgb +=secondary_light * light_distance_fading(dist);} + } + + texel = texture2D(texture, gl_TexCoord[0].st); + fragColor = color * texel + specular; + + +float lightArg = (terminator-yprime_alt)/100000.0; + +vec3 hazeColor = get_hazeColor(lightArg); + + +// Rayleigh color shift due to in-scattering + + if ((quality_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); + fragColor.rgb = rayleigh_out_shift(fragColor.rgb,outscatter); + 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); + 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; + +// 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,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; + } + } + + +// 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; + +//float scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, relPos.z + eye_alt); + +if (visibility < avisibility) + { + 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 + { + 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; + + + + + + + +// 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)) ); + } + +// high altitude desaturation of the haze color + +intensity = length(hazeColor); +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 +//intensity = length(hazeColor); +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(normal,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); + +// determine the right mix of transmission and haze + + +fragColor.rgb = mix(hazeColor + secondary_light * fog_backscatter(mvisibility), fragColor.rgb,transmission); + + + +} + +gl_FragColor = fragColor; + + +} + diff --git a/Shaders/space-ALS-base.vert b/Shaders/space-ALS-base.vert new file mode 100644 index 000000000..96447e27b --- /dev/null +++ b/Shaders/space-ALS-base.vert @@ -0,0 +1,264 @@ +// -*-C++-*- + +// Shader that uses OpenGL state values to do per-pixel lighting +// +// The only light used is gl_LightSource[0], which is assumed to be +// directional. +// +// Diffuse colors come from the gl_Color, ambient from the material. This is +// equivalent to osg::Material::DIFFUSE. +// Haze part added by Thorsten Renk, Oct. 2011 + + +#define MODE_OFF 0 +#define MODE_DIFFUSE 1 +#define MODE_AMBIENT_AND_DIFFUSE 2 + +// The constant term of the lighting equation that doesn't depend on +// the surface normal is passed in gl_{Front,Back}Color. The alpha +// component is set to 1 for front, 0 for back in order to work around +// bugs with gl_FrontFacing in the fragment shader. +varying vec4 diffuse_term; +varying vec3 normal; +varying vec3 relPos; + +varying float yprime_alt; +varying float mie_angle; +varying float alt_factor; + +uniform int colorMode; +uniform float hazeLayerAltitude; +uniform float terminator; +uniform float terrain_alt; +uniform float avisibility; +uniform float visibility; +uniform float overcast; +uniform float ground_scattering; +uniform float moonlight; +uniform float eye_alt; + + +// This is the value used in the skydome scattering shader - use the same here for consistency? +const float EarthRadius = 5800000.0; +const float terminator_width = 200000.0; + + +float earthShade; + +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 < -15.0) {return 0.0;} + +return e / pow((1.0 + a * exp(-b * (x-c)) ),(1.0/d)); +} + + +void main() +{ + + vec4 light_diffuse; + vec4 light_ambient; + vec3 shadedFogColor = vec3(0.55, 0.67, 0.88); + vec3 moonLightColor = vec3 (0.095, 0.095, 0.15) * moonlight; + + + //float yprime_alt; + float yprime; + float lightArg; + float intensity; + float vertex_alt; + float scattering; + +// this code is copied from default.vert + + //vec4 ecPosition = gl_ModelViewMatrix * gl_Vertex; + gl_Position = ftransform(); + gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0; + normal = gl_NormalMatrix * gl_Normal; + vec4 ambient_color, diffuse_color; + if (colorMode == MODE_DIFFUSE) { + diffuse_color = gl_Color; + ambient_color = gl_FrontMaterial.ambient; + } else if (colorMode == MODE_AMBIENT_AND_DIFFUSE) { + diffuse_color = gl_Color; + ambient_color = gl_Color; + } else { + diffuse_color = gl_FrontMaterial.diffuse; + ambient_color = gl_FrontMaterial.ambient; + } + + + + // here start computations for the haze layer + // we need several geometrical quantities + + // first current altitude of eye position in model space + vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); + + // and relative position to vector + relPos = gl_Vertex.xyz - ep.xyz; + + // unfortunately, we need the distance in the vertex shader, although the more accurate version + // is later computed in the fragment shader again + float dist = length(relPos); + + // altitude of the vertex in question, somehow zero leads to artefacts, so ensure it is at least 100m + vertex_alt = max(gl_Vertex.z,100.0); + scattering = ground_scattering + (1.0 - ground_scattering) * smoothstep(hazeLayerAltitude -100.0, hazeLayerAltitude + 100.0, vertex_alt); + + + // branch dependent on daytime + +if (terminator < 1000000.0) // the full, sunrise and sunset computation +{ + + + // establish coordinates relative to sun position + + vec3 lightFull = (gl_ModelViewMatrixInverse * gl_LightSource[0].position).xyz; + vec3 lightHorizon = normalize(vec3(lightFull.x,lightFull.y, 0.0)); + + + + // yprime is the distance of the vertex into sun direction + yprime = -dot(relPos, lightHorizon); + + // this gets an altitude correction, higher terrain gets to see the sun earlier + yprime_alt = yprime - sqrt(2.0 * EarthRadius * vertex_alt); + + // two times terminator width governs how quickly light fades into shadow + // now the light-dimming factor + earthShade = 0.6 * (1.0 - smoothstep(-terminator_width+ terminator, terminator_width + terminator, yprime_alt)) + 0.4; + + // parametrized version of the Flightgear ground lighting function + lightArg = (terminator-yprime_alt)/100000.0; + + // directional scattering for low sun + if (lightArg < 10.0) + {mie_angle = (0.5 * dot(normalize(relPos), normalize(lightFull)) ) + 0.5;} + else + {mie_angle = 1.0;} + + + + + light_diffuse.b = light_func(lightArg, 1.330e-05, 0.264, 3.827, 1.08e-05, 1.0); + light_diffuse.g = light_func(lightArg, 3.931e-06, 0.264, 3.827, 7.93e-06, 1.0); + light_diffuse.r = light_func(lightArg, 8.305e-06, 0.161, 3.827, 3.04e-05, 1.0); + light_diffuse.a = 1.0; + light_diffuse = light_diffuse * scattering; + + + light_ambient.r = light_func(lightArg, 0.236, 0.253, 1.073, 0.572, 0.33); + light_ambient.g = light_ambient.r * 0.4/0.33; + light_ambient.b = light_ambient.r * 0.5/0.33; + light_ambient.a = 1.0; + + + + +// correct ambient light intensity and hue before sunrise +if (earthShade < 0.5) + { + //light_ambient = light_ambient * (0.7 + 0.3 * smoothstep(0.2, 0.5, earthShade)); + intensity = length(light_ambient.rgb); + + light_ambient.rgb = intensity * normalize(mix(light_ambient.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.8,earthShade) )); + + + intensity = length(light_diffuse.rgb); + light_diffuse.rgb = intensity * normalize(mix(light_diffuse.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.7,earthShade) )); + } + + +// the haze gets the light at the altitude of the haze top if the vertex in view is below +// but the light at the vertex if the vertex is above + +vertex_alt = max(vertex_alt,hazeLayerAltitude); + +if (vertex_alt > hazeLayerAltitude) + { + if (dist > 0.8 * avisibility) + { + vertex_alt = mix(vertex_alt, hazeLayerAltitude, smoothstep(0.8*avisibility, avisibility, dist)); + yprime_alt = yprime -sqrt(2.0 * EarthRadius * vertex_alt); + } + } +else + { + vertex_alt = hazeLayerAltitude; + yprime_alt = yprime -sqrt(2.0 * EarthRadius * vertex_alt); + } + +} +else // the faster, full-day version without lightfields +{ + //vertex_alt = max(gl_Vertex.z,100.0); + + earthShade = 1.0; + mie_angle = 1.0; + + if (terminator > 3000000.0) + {light_diffuse = vec4 (1.0, 1.0, 1.0, 0.0); + light_ambient = vec4 (0.33, 0.4, 0.5, 0.0); } + else + { + + lightArg = (terminator/100000.0 - 10.0)/20.0; + light_diffuse.b = 0.78 + lightArg * 0.21; + light_diffuse.g = 0.907 + lightArg * 0.091; + light_diffuse.r = 0.904 + lightArg * 0.092; + light_diffuse.a = 1.0; + + light_ambient.r = 0.316 + lightArg * 0.016; + light_ambient.g = light_ambient.r * 0.4/0.33; + light_ambient.b = light_ambient.r * 0.5/0.33; + light_ambient.a = 1.0; + } + + light_diffuse = light_diffuse * scattering; + yprime_alt = -sqrt(2.0 * EarthRadius * hazeLayerAltitude); +} + +// at high altitude, the light gets de-saturated and the ambient channel dies out +// whereas the diffuse channel is enhanced + + alt_factor = smoothstep(10000.0, 100000.0, eye_alt); + float ambient_reduction = 0.25 + 0.75 * (1.0-alt_factor); + float diffuse_enhancement = 1.0 + 1.0 * (1.0 - ambient_reduction); + + light_ambient.rgb = light_ambient.rgb * ambient_reduction; + light_diffuse.rgb = light_diffuse.rgb * diffuse_enhancement; + light_ambient.rgb = light_ambient.rgb + moonLightColor * (1.0 - smoothstep(0.4, 0.5, earthShade)); + + vec3 sky_blue = normalize (vec3 (0.17, 0.52, 0.87)); + intensity = length(light_ambient.rgb); + light_ambient.rgb = mix(light_ambient.rgb, intensity * sky_blue, alt_factor); + + intensity = length(light_diffuse.rgb); + light_diffuse.rgb = mix(light_diffuse.rgb, intensity * vec3 (1.0,1.0,1.0), alt_factor); + +// default lighting based on texture and material using the light we have just computed + + diffuse_term = diffuse_color* light_diffuse; + vec4 constant_term = gl_FrontMaterial.emission + ambient_color * + (gl_LightModel.ambient + light_ambient); + // Super hack: if diffuse material alpha is less than 1, assume a + // transparency animation is at work + if (gl_FrontMaterial.diffuse.a < 1.0) + diffuse_term.a = gl_FrontMaterial.diffuse.a; + else + diffuse_term.a = gl_Color.a; + // Another hack for supporting two-sided lighting without using + // gl_FrontFacing in the fragment shader. + gl_FrontColor.rgb = constant_term.rgb; gl_FrontColor.a = 1.0; + gl_BackColor.rgb = constant_term.rgb; gl_BackColor.a = 0.0; + +} + + + +