// WS30 VERTEX SHADER // -*-C++-*- #version 120 // 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. // // Colors are not assigned in this shader, as they will come from // the landclass lookup in the fragment shader. // 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 light_diffuse_comp; varying vec3 normal; varying vec3 relPos; varying vec2 ground_tex_coord; varying vec2 rawPos; varying vec3 worldPos; varying vec3 ecViewdir; varying vec2 grad_dir; varying vec4 ecPosition; varying vec3 vertVec; // Sent packed into alpha channels //varying float yprime_alt; varying float mie_angle; varying float steepness; uniform int colorMode; uniform bool raise_vertex; 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 eye_alt; uniform float moonlight; uniform bool use_IR_vision; uniform mat4 osg_ViewMatrixInverse; // From VPBTechnique.cxx uniform mat4 fg_zUpTransform; uniform vec3 fg_modelOffset; float earthShade; float yprime_alt; vec3 moonlight_perception (in vec3 light); void setupShadows(vec4 eyeSpacePos); // 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 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 + vec3 (0.005, 0.005, 0.005); moonLightColor = moonlight_perception (moonLightColor); //float yprime_alt; float yprime; float lightArg; float intensity; float vertex_alt; float scattering; // The ALS code assumes that units are in meters - e.g. model space vertices (gl_Vertex) are in meters // WS30 model space, Nov 21, 2021: // Coordinate axes are the same for geocentric, but not the origin. // +z direction points from the Earth center to North pole. // +x direction points from the Earth center to longitude = 0 on the equator. // +y direction points from the Earth center to logntitude = East on the equator. // Model space origin is at sea level. Units are in meters. // Each tile, for each LoD level, its own model origin // modelOffset is the model origin relative to the Earth center. It is in a geocentric // space with the same axes, but with the Earth center as the origin. Units are in meters. vec4 pos = gl_Vertex; if (raise_vertex) { pos.z+=0.1; gl_Position = gl_ModelViewProjectionMatrix * pos; } else gl_Position = ftransform(); // this code is copied from default.vert ecPosition = gl_ModelViewMatrix * gl_Vertex; //gl_Position = ftransform(); gl_TexCoord[0] = gl_TextureMatrix[0] * gl_MultiTexCoord0; normal = gl_NormalMatrix * gl_Normal; /////////////////////////////////////////// // Test phase code: // // Coords for ground textures // Due to precision issues coordinates should restart (i.e. go to zero) every 5000m or so. const float restart_dist_m = 5000.0; // Model position vec3 mp = gl_Vertex.xyz; // Temporary approximation to get shaders to compile: ground_tex_coord = gl_TexCoord[0].st; // // End test phase code /////////////////////////////////////////// // WS2: // 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; // Transform for frame of reference where: // +z is in the up direction. // The orientation of x and y axes are unknown currently. // The origin is at the same position as the model space origin. // The units are in meters. mat4 viewSpaceToZUpSpace = fg_zUpTransform * gl_ModelViewMatrixInverse; vec4 vertexZUp = fg_zUpTransform * gl_Vertex; // WS2: rawPos = gl_Vertex.xy; rawPos = vertexZUp.xy; // WS2: worldPos = (osg_ViewMatrixInverse *gl_ModelViewMatrix * gl_Vertex).xyz; worldPos = fg_modelOffset + gl_Vertex.xyz; steepness = dot(normalize(vec3(fg_zUpTransform * vec4(gl_Normal,1.0))), vec3 (0.0, 0.0, 1.0)); // Gradient direction used for small scale noise. In the same space as noise coords, rawpos.xy. grad_dir = normalize(gl_Normal.xy); // here start computations for the haze layer // we need several geometrical quantities // Eye position in z up space vec4 epZUp = viewSpaceToZUpSpace * vec4(0.0,0.0,0.0,1.0); // Position of vertex relative to the eye position in z up space vec3 relPosZUp = (vertexZUp - epZUp).xyz; // first current altitude of eye position in model space vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); // Eye position in model space vec4 epMS = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); /* //old: and relative position to vector. This is also used for cloud shadow positioning. relPosOld = (fg_zUpTransform * vec4(gl_Vertex - ep)).xyz; if (any(notEqual(relPosOld, relPosZUp))) relPos = vec3(1000000.0); */ relPos = relPosZUp; vertVec = relPosZUp; ecViewdir = (gl_ModelViewMatrix * (epMS - gl_Vertex)).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 above mean sea level in meters. // This is equal to vertexZUp.z as the model space origin is at mean sea level. // Somehow zero leads to artefacts, so ensure it is at least 100m. //WS2: vertex_alt = max(gl_Vertex.z,100.0); vertex_alt = max(vertexZUp.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.b = light_func(lightArg, 0.000506, 0.131, -3.315, 0.000457, 0.5); //light_ambient.g = light_func(lightArg, 2.264e-05, 0.134, 0.967, 3.66e-05, 0.4); 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_func(lightArg, 0.236, 0.253, 1.073, 0.572, 0.4); light_ambient.b = light_ambient.r * 0.5/0.33; //light_func(lightArg, 0.236, 0.253, 1.073, 0.572, 0.5); light_ambient.a = 1.0; // correct ambient light intensity and hue before sunrise if (earthShade < 0.5) { intensity = length(light_ambient.rgb); light_ambient.rgb = intensity * normalize(mix(light_ambient.rgb, shadedFogColor, 1.0 -smoothstep(0.4, 0.8,earthShade) )); light_ambient.rgb = light_ambient.rgb + moonLightColor * (1.0 - smoothstep(0.4, 0.5, 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); } } // End if (terminator < 1000000.0) 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, 1.0); light_ambient = vec4 (0.33, 0.4, 0.5, 1.0); } 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.b = 0.41 + lightArg * 0.08; //light_ambient.g = 0.333 + lightArg * 0.06; 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); } //End the faster, full-day version without lightfields // a sky/earth irradiation map model - the sky creates much more diffuse radiation than the ground, so // steep faces end up shaded more light_ambient = light_ambient * ((1.0+steepness)/2.0 * 1.2 + (1.0-steepness)/2.0 * 0.2); // deeper shadows when there is lots of direct light float shade_depth = 1.0 * smoothstep (0.6,0.95,ground_scattering) * (1.0-smoothstep(0.1,0.5,overcast)) * smoothstep(0.4,1.5,earthShade); light_ambient.rgb = light_ambient.rgb * (1.0 - shade_depth); light_diffuse.rgb = light_diffuse.rgb * (1.0 + 1.2 * shade_depth); if (use_IR_vision) { light_ambient.rgb = max(light_ambient.rgb, vec3 (0.5, 0.5, 0.5)); } // default lighting based on texture and material using the light we have just computed light_diffuse_comp = light_diffuse; //Testing phase code: ambient colours are not sent to fragement shader yet. // They are all default except for water/ocean etc. currently // Emission is all set to the default of vec4(0.0, 0.0, 0.0, 1.0) //To do: Fix this once ambient colour becomes available in the fragment shaders. //const vec4 ambient_color = vec4(0.2, 0.2, 0.2, 1.0); const vec4 ambient_color = vec4(1.0); vec4 constant_term = ambient_color * (gl_LightModel.ambient + light_ambient); light_diffuse_comp.a = yprime_alt; gl_FrontColor.rgb = constant_term.rgb; // gl_FrontColor.a = 1.0; gl_BackColor.rgb = constant_term.rgb; // gl_BackColor.a = 0.0; gl_FrontColor.a = mie_angle; gl_BackColor.a = mie_angle; setupShadows(ecPosition); }