EG/RenderPipelineFile/rpplugins/clouds/shader/render_clouds.frag.glsl
2025-07-24 11:37:46 +08:00

225 lines
7.6 KiB
GLSL

/**
*
* RenderPipeline
*
* Copyright (c) 2014-2016 tobspr <tobias.springer1@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
*/
#version 430
// Renders the clouds
// WORK IN PROGRESS - This shader is unfinished and not cleaned up yet.
#define USE_TIME_OF_DAY 1
#pragma include "render_pipeline_base.inc.glsl"
#define USE_GBUFFER_EXTENSIONS
#pragma include "includes/gbuffer.inc.glsl"
#pragma include "includes/light_culling.inc.glsl"
#pragma include "includes/noise.inc.glsl"
uniform sampler3D Noise1;
uniform sampler3D Noise2;
uniform sampler2D WeatherTex;
out vec4 result;
const float KM = 1000.0;
const float METER = 1.0;
const float earth_radius = 6371.0 * KM;
const vec3 earth_mid = vec3(0, 0, -earth_radius);
const float cloud_start = earth_radius + 1.3 * KM;
const float cloud_end = earth_radius + 25.0 * KM;
float GetHeightFractionForPoint(vec3 inPosition, vec2 inCloudMinMax)
{
float height_fraction = (inPosition.z - inCloudMinMax.x) / (inCloudMinMax.y - inCloudMinMax.x);
return saturate(height_fraction);
}
float GetDensityHeightGradientForPoint(vec3 p, vec3 weatherData) {
// return saturate(20.0 * (1.0 - max(0, p.z / 0.3)) ); // XXX
// return p.z > 0.1 ? 0.0 : 1.0;
// return pow(p.z, 0.3);
return 1.0;
}
float SampleCloudDensity(vec3 p, vec3 weather_data, float mip_level)
{
// float3 wind_direction = float3 (1.0 , 0.0 , 0.0) ;
// float cloud_speed = 10.0;
// float cloud_top_offset = 500.0;
// p += height_fraction * wind_direction * cloud_top_offset;
vec4 low_frequency_noises = textureLod(Noise1, p * 0.6, mip_level);
float low_freq_FBM = (low_frequency_noises.g * 0.625)
+ (low_frequency_noises.b * 0.25)
+ (low_frequency_noises.a * 0.125);
float base_cloud = max(0, square(low_frequency_noises.x * low_frequency_noises.y) - 0.07) ;
// base_cloud = pow(base_cloud, 10.0) * 10.0;
// base_cloud *= max(0, low_frequency_noises.w * 1.4 - 0.2);
// base_cloud *= max(0, low_frequency_noises.z * 1.5 - 0.2);
float density_height_gradient = GetDensityHeightGradientForPoint(p, weather_data);
base_cloud *= density_height_gradient;
float cloud_coverage = weather_data.r;
// base_cloud *= cloud_coverage;
vec3 high_frequency_noises = textureLod(Noise2, p * 5.63534, mip_level).rgb;
// float high_freq_FBM = (high_frequency_noises.r * 0.625);
// + (high_frequency_noises.g * 0.25)
// + (high_frequency_noises.b * 0.125);
// base_cloud = mix(high_frequency_noises.y * base_cloud, 1, base_cloud);
base_cloud -= high_frequency_noises.y * 0.23 * (1 - base_cloud);
// base_cloud *= 3.0;
base_cloud *= 125.0 * 256.0 / GET_SETTING(clouds, raymarch_steps);
return saturate(base_cloud);
}
vec2 get_cloud_coord(vec3 pos) {
vec2 xy_coord = pos.xy / (cloud_end - cloud_start);
xy_coord.xy /= 1.0 + 0.1 * length(xy_coord);
// xy_coord.xy += 0.5;
// xy_coord *= 0.5;
return xy_coord;
}
float HenyeyGreenstein(vec3 inLightVector, vec3 inViewVector, float inG)
{
float cos_angle = dot(normalize(inLightVector), normalize(inViewVector));
return ((1.0 - inG * inG) / pow((1.0 + inG * inG - 2.0 * inG * cos_angle),
3.0 / 2.0)) / 4.0 * M_PI;
}
void main() {
int num_samples = GET_SETTING(clouds, raymarch_steps);
// int num_samples = 256;
vec2 texcoord = get_half_texcoord();
vec3 wind_offs = vec3(0.2, 0.3, 0) * 0.052 * MainSceneData.frame_time;
vec3 pos = get_gbuffer_position(GBuffer, texcoord);
vec3 ray_start = MainSceneData.camera_pos;
vec3 ray_dir = normalize(pos - ray_start);
vec3 view_vector = normalize(MainSceneData.camera_pos - pos);
if (!is_skybox(pos) || ray_dir.z < 0.0) {
result = vec4(0);
return;
}
float t_low, t_high, tmp;
Sphere earth_sphere;
earth_sphere.pos = earth_mid;
earth_sphere.radius = cloud_start;
bool rb = ray_sphere_intersection(earth_sphere, ray_start, ray_dir, t_low, tmp);
earth_sphere.radius = cloud_end;
bool rt = ray_sphere_intersection(earth_sphere, ray_start, ray_dir, t_high, tmp);
if (t_low < 0.0) t_low = 0.0;
if (t_high < 0.0 || distance(t_high, t_low) < 0.01) {
result = vec4(0.2, 0, 0, 0);
return;
}
// Get start and end in cloud space coordinates
vec3 trace_start = vec3(get_cloud_coord(ray_start + t_low * ray_dir), 0.0);
vec3 trace_end = vec3(get_cloud_coord(ray_start + t_high * ray_dir), 1.0);
trace_start += wind_offs;
trace_end += wind_offs;
// trace_start.xyz += (noise*2.0-1.0) * 0.004;
vec3 trace_step = (trace_end - trace_start) / float(num_samples);
// trace_step.xyz += (noise*2.0-1.0) * 0.015 / num_samples;
float density = 0.0;
float cloud_test = 0.0;
int zero_density_sample_count = 0;
float mip_level = 0;
float jitter = abs(rand(ivec2(gl_FragCoord.xy)));
vec3 p = trace_start + (1 + jitter) * trace_step;
vec3 accum_color = vec3(0);
vec3 sun_vector = get_sun_vector();
vec3 weather_data = texture(WeatherTex, p.xy).xyz;
for (int i = 0; i < num_samples - 1; ++i)
{
float sampled_density = SampleCloudDensity(p, weather_data, mip_level) * 0.2;
float sampled_sun_density = 0.0;
for (int k = 1; k < 3; ++k) {
sampled_sun_density += SampleCloudDensity(
p + sun_vector * 1.0 / 256.0 * k * k, weather_data, mip_level);
}
sampled_density *= (1 - density);
density += sampled_density;
accum_color += ((0.05 + 0.99 * p.z * p.z) * sampled_density *
(1.0 - sampled_sun_density / 3.0));
p += trace_step;
}
float accum_weight = density;
float light_samples = density * 1.0;
float powder_sugar_effect = 1.0 - exp(- light_samples * 2.0);
float beers_law = exp(-light_samples);
float light_energy = 2.0 * beers_law * powder_sugar_effect;
accum_color *= light_energy * 2.0;
accum_color *= vec3(HenyeyGreenstein(sun_vector, -view_vector, 0.2)) * 1.0;
float sun_influence = pow(max(0, dot(ray_dir, sun_vector)), 25.0) + 0.0;
vec3 sun_color = sun_influence * 100.0 * TimeOfDay.scattering.sun_color;
accum_color *= 1.0 + sun_color * max(0, 1 - 0.7 * density);
accum_color *= TimeOfDay.clouds.cloud_brightness * 20.0 * vec3(10, 10, 15);
accum_color *= TimeOfDay.scattering.sun_intensity / 150.0;
accum_color *= TimeOfDay.scattering.sun_color;
// Don't render clouds at obligue angles
float horizon = pow(saturate(ray_dir.z * 1.0), 0.1);
accum_color *= horizon;
accum_weight *= horizon;
result = vec4(accum_color, accum_weight);
}