/** * @file atmosphericsV.glsl * * $LicenseInfo:firstyear=2005&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2005, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ // VARYING param funcs void setSunlitColor(vec3 v); void setAmblitColor(vec3 v); void setAdditiveColor(vec3 v); void setAtmosAttenuation(vec3 v); void setPositionEye(vec3 v); vec3 getAdditiveColor(); //VARYING vec4 vary_CloudUVs; //VARYING float vary_CloudDensity; // Inputs uniform vec4 morphFactor; uniform vec3 camPosLocal; //uniform vec4 camPosWorld; uniform vec4 lightnorm; uniform vec4 sunlight_color; uniform vec4 ambient; uniform vec4 blue_horizon; uniform vec4 blue_density; uniform float haze_horizon; uniform float haze_density; uniform float cloud_shadow; uniform float density_multiplier; uniform float distance_multiplier; uniform float max_y; uniform vec4 glow; void calcAtmospherics(vec3 inPositionEye) { vec3 P = inPositionEye; setPositionEye(P); //(TERRAIN) limit altitude if (P.y > max_y) P *= (max_y / P.y); if (P.y < -max_y) P *= (-max_y / P.y); vec3 tmpLightnorm = lightnorm.xyz; vec3 Pn = normalize(P); float Plen = length(P); vec4 temp1 = vec4(0); vec3 temp2 = vec3(0); vec4 blue_weight; vec4 haze_weight; vec4 sunlight = sunlight_color; vec4 light_atten; //sunlight attenuation effect (hue and brightness) due to atmosphere //this is used later for sunlight modulation at various altitudes light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y); //I had thought blue_density and haze_density should have equal weighting, //but attenuation due to haze_density tends to seem too strong temp1 = blue_density + vec4(haze_density); blue_weight = blue_density / temp1; haze_weight = vec4(haze_density) / temp1; //(TERRAIN) compute sunlight from lightnorm only (for short rays like terrain) temp2.y = max(0.0, tmpLightnorm.y); temp2.y = 1. / temp2.y; sunlight *= exp( - light_atten * temp2.y); // main atmospheric scattering line integral temp2.z = Plen * density_multiplier; // Transparency (-> temp1) // ATI Bugfix -- can't store temp1*temp2.z*distance_multiplier in a variable because the ati // compiler gets confused. temp1 = exp(-temp1 * temp2.z * distance_multiplier); //final atmosphere attenuation factor setAtmosAttenuation(temp1.rgb); //vary_AtmosAttenuation = distance_multiplier / 10000.; //vary_AtmosAttenuation = density_multiplier * 100.; //vary_AtmosAttenuation = vec4(Plen / 100000., 0., 0., 1.); //compute haze glow //(can use temp2.x as temp because we haven't used it yet) temp2.x = dot(Pn, tmpLightnorm.xyz); temp2.x = 1. - temp2.x; //temp2.x is 0 at the sun and increases away from sun temp2.x = max(temp2.x, .03); //was glow.y //set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot) temp2.x *= glow.x; //higher glow.x gives dimmer glow (because next step is 1 / "angle") temp2.x = pow(temp2.x, glow.z); //glow.z should be negative, so we're doing a sort of (1 / "angle") function //add "minimum anti-solar illumination" temp2.x += .25; //increase ambient when there are more clouds vec4 tmpAmbient = ambient + (vec4(1.) - ambient) * cloud_shadow * 0.5; vec3 additive = vec3(blue_horizon * blue_weight * (sunlight*(1.-cloud_shadow) + tmpAmbient) + (haze_horizon * haze_weight) * (sunlight*(1.-cloud_shadow) * temp2.x + tmpAmbient)); additive = normalize(additive); //haze color //setAdditiveColor( // vec3(blue_horizon * blue_weight * (sunlight*(1.-cloud_shadow) + tmpAmbient) // + (haze_horizon * haze_weight) * (sunlight*(1.-cloud_shadow) * temp2.x // + tmpAmbient))); //brightness of surface both sunlight and ambient setSunlitColor(vec3(sunlight * .5)); setAmblitColor(vec3(tmpAmbient * .25)); setAdditiveColor(additive * vec3(1.0 - exp(-temp2.z * distance_multiplier)) * 0.5); // vary_SunlitColor = vec3(0); // vary_AmblitColor = vec3(0); // vary_AdditiveColor = vec4(Pn, 1.0); /* const float cloudShadowScale = 100.; // Get cloud uvs for shadowing vec3 cloudPos = inPositionEye + camPosWorld - cloudShadowScale / 2.; vary_CloudUVs.xy = cloudPos.xz / cloudShadowScale; // We can take uv1 and multiply it by (TerrainSpan / CloudSpan) // cloudUVs *= (((worldMaxZ - worldMinZ) * 20) /40000.); vary_CloudUVs *= (10000./40000.); // Offset by sun vector * (CloudAltitude / CloudSpan) vary_CloudUVs.x += tmpLightnorm.x / tmpLightnorm.y * (3000./40000.); vary_CloudUVs.y += tmpLightnorm.z / tmpLightnorm.y * (3000./40000.); */ }