1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/**
* @file atmosphericsF.glsl
*
* $LicenseInfo:firstyear=2007&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2007, 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
* $/LicenseInfo$
*/
vec3 getAdditiveColor();
vec3 getAtmosAttenuation();
uniform sampler2D cloudMap;
uniform vec4 gamma;
uniform vec4 cloud_pos_density1;
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;
uniform float scene_light_strength;
uniform mat3 ssao_effect_mat;
uniform int no_atmo;
vec3 scaleFragSoftClip(vec3 light)
{
if (no_atmo == 1)
{
return light;
}
//soft clip effect:
light = 1. - clamp(light, vec3(0.), vec3(1.));
light = 1. - pow(light, gamma.xxx);
return light;
}
vec3 atmosFragLighting(vec3 light, vec3 additive, vec3 atten)
{
if (no_atmo == 0)
{
light *= atten.r;
light += additive;
}
return (2.0 * light);
}
vec3 atmosLighting(vec3 light)
{
return (no_atmo == 1) ? light : atmosFragLighting(light, getAdditiveColor(), getAtmosAttenuation());
}
void calcFragAtmospherics(vec3 inPositionEye, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten) {
vec3 P = inPositionEye;
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
atten = temp1.rgb;
//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;
/* decrease value and saturation (that in HSV, not HSL) for occluded areas
* // for HSV color/geometry used here, see http://gimp-savvy.com/BOOK/index.html?node52.html
* // The following line of code performs the equivalent of:
* float ambAlpha = tmpAmbient.a;
* float ambValue = dot(vec3(tmpAmbient), vec3(0.577)); // projection onto <1/rt(3), 1/rt(3), 1/rt(3)>, the neutral white-black axis
* vec3 ambHueSat = vec3(tmpAmbient) - vec3(ambValue);
* tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat, ambAlpha);
*/
tmpAmbient = vec4(mix(ssao_effect_mat * tmpAmbient.rgb, tmpAmbient.rgb, ambFactor), tmpAmbient.a);
//haze color
additive =
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
sunlit = vec3(sunlight * .5);
amblit = vec3(tmpAmbient * .25);
additive *= vec3(1.0 - temp1);
}
|
