c4d19877cf
- New atmosphering rendering technique based on my own work. - Attempt to fix some remaining transparency issues. - Use a luminance histogram for auto exposure. - Add support for clustered shading. - Add WS 2.0 shaders. - Add 3D cloud shaders. - Add orthoscenery support.
54 lines
1.7 KiB
GLSL
54 lines
1.7 KiB
GLSL
#version 330 core
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out vec4 fragColor;
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in vec2 texCoord;
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uniform sampler2D transmittance_lut;
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uniform float fg_SunZenithCosTheta;
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uniform float fg_CameraDistanceToEarthCenter;
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const float PI = 3.14159265358979323846;
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const int SKY_STEPS = 32;
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// atmos-include.frag
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vec4 compute_inscattering(in vec3 ray_origin,
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in vec3 ray_dir,
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in float t_max,
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in vec3 sun_dir,
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in int steps,
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in sampler2D transmittance_lut,
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out vec4 transmittance);
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void main()
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{
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// Always leave the Sun right in the middle of the sky texture.
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// The skydome model implemented in SimGear already takes care of rotating
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// the Sun for us.
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vec3 sun_dir = vec3(
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-sqrt(1.0 - fg_SunZenithCosTheta*fg_SunZenithCosTheta),
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0.0,
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fg_SunZenithCosTheta);
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float azimuth = 2.0 * PI * texCoord.x; // [0, 2pi]
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// Apply a non-linear transformation to the elevation to dedicate more
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// texels to the horizon, where having more detail matters.
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float l = texCoord.y * 2.0 - 1.0;
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float elev = l*l * sign(l) * PI * 0.5; // [-pi/2, pi/2]
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vec3 ray_dir = vec3(cos(elev) * cos(azimuth),
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cos(elev) * sin(azimuth),
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sin(elev));
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vec3 ray_origin = vec3(0.0, 0.0, fg_CameraDistanceToEarthCenter);
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vec4 transmittance;
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vec4 L = compute_inscattering(ray_origin,
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ray_dir,
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1e7,
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sun_dir,
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SKY_STEPS,
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transmittance_lut,
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transmittance);
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fragColor = L;
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}
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