Initial implementation of 'Godrays'

This commit is contained in:
x2048 2023-10-09 11:58:58 -07:00 committed by lhofhansl
parent cad8e895f2
commit 04f0d545da
3 changed files with 148 additions and 2 deletions

@ -1,13 +1,28 @@
#define rendered texture0
#define depthmap texture2
struct ExposureParams {
float compensationFactor;
};
uniform sampler2D rendered;
uniform sampler2D depthmap;
uniform mediump float bloomStrength;
uniform ExposureParams exposureParams;
uniform vec3 sunPositionScreen;
uniform float sunBrightness;
uniform vec3 moonPositionScreen;
uniform float moonBrightness;
uniform vec3 dayLight;
#ifdef ENABLE_DYNAMIC_SHADOWS
uniform vec3 v_LightDirection;
#else
const vec3 v_LightDirection = vec3(0.0, -1.0, 0.0);
#endif
#ifdef GL_ES
varying mediump vec2 varTexCoord;
#else
@ -18,6 +33,80 @@ centroid varying vec2 varTexCoord;
varying float exposure; // linear exposure factor, see vertex shader
#endif
const float far = 1000.;
const float near = 1.;
float mapDepth(float depth)
{
return min(1., 1. / (1.00001 - depth) / far);
}
float noise(vec3 uvd) {
return fract(dot(sin(uvd * vec3(13041.19699, 27723.29171, 61029.77801)), vec3(73137.11101, 37312.92319, 10108.89991)));
}
float sampleVolumetricLight(vec2 uv, vec3 lightVec, float rawDepth)
{
lightVec = 0.5 * lightVec / lightVec.z + 0.5;
const float samples = 30.;
float result = texture2D(depthmap, uv).r < 1. ? 0.0 : 1.0;
float bias = noise(vec3(uv, rawDepth));
vec2 samplepos;
for (float i = 1.; i < samples; i++) {
samplepos = mix(uv, lightVec.xy, (i + bias) / samples);
if (min(samplepos.x, samplepos.y) > 0. && max(samplepos.x, samplepos.y) < 1.)
result += texture2D(depthmap, samplepos).r < 1. ? 0.0 : 1.0;
}
return result / samples;
}
vec3 getDirectLightScatteringAtGround(vec3 v_LightDirection)
{
// Based on talk at 2002 Game Developers Conference by Naty Hoffman and Arcot J. Preetham
const float beta_r0 = 1e-5; // Rayleigh scattering beta
// These factors are calculated based on expected value of scattering factor of 1e-5
// for Nitrogen at 532nm (green), 2e25 molecules/m3 in atmosphere
const vec3 beta_r0_l = vec3(3.3362176e-01, 8.75378289198826e-01, 1.95342379700656) * beta_r0; // wavelength-dependent scattering
const float atmosphere_height = 15000.; // height of the atmosphere in meters
// sun/moon light at the ground level, after going through the atmosphere
return exp(-beta_r0_l * atmosphere_height / (1e-5 - dot(v_LightDirection, vec3(0., 1., 0.))));
}
vec3 applyVolumetricLight(vec3 color, vec2 uv, float rawDepth)
{
vec3 lookDirection = normalize(vec3(uv.x * 2. - 1., uv.y * 2. - 1., rawDepth));
vec3 lightSourceTint = vec3(1.0, 0.98, 0.4);
const float boost = 4.0;
float brightness = 0.;
vec3 sourcePosition = vec3(-1., -1., -1);
if (sunPositionScreen.z > 0. && sunBrightness > 0.) {
brightness = sunBrightness;
sourcePosition = sunPositionScreen;
}
else if (moonPositionScreen.z > 0. && moonBrightness > 0.) {
lightSourceTint = vec3(0.4, 0.9, 1.);
brightness = moonBrightness * 0.05;
sourcePosition = moonPositionScreen;
}
float cameraDirectionFactor = pow(clamp(dot(sourcePosition, vec3(0., 0., 1.)), 0.0, 0.7), 2.5);
float viewAngleFactor = pow(max(0., dot(sourcePosition, lookDirection)), 8.);
float lightFactor = brightness * sampleVolumetricLight(uv, sourcePosition, rawDepth) *
(0.05 * cameraDirectionFactor + 0.95 * viewAngleFactor);
color = mix(color, boost * getDirectLightScatteringAtGround(v_LightDirection) * dayLight, lightFactor);
// if (sunPositionScreen.z < 0.)
// color.rg += 1. - clamp(abs((2. * uv.xy - 1.) - sunPositionScreen.xy / sunPositionScreen.z) * 1000., 0., 1.);
// if (moonPositionScreen.z < 0.)
// color.rg += 1. - clamp(abs((2. * uv.xy - 1.) - moonPositionScreen.xy / moonPositionScreen.z) * 1000., 0., 1.);
return color;
}
void main(void)
{
vec2 uv = varTexCoord.st;
@ -31,5 +120,9 @@ void main(void)
color *= exposure;
#endif
float rawDepth = texture2D(depthmap, uv).r;
color = applyVolumetricLight(color, uv, rawDepth);
gl_FragColor = vec4(color, 1.0); // force full alpha to avoid holes in the image.
}

@ -404,6 +404,10 @@ class GameGlobalShaderConstantSetter : public IShaderConstantSetter
CachedPixelShaderSetting<float> m_bloom_radius_pixel;
float m_bloom_radius;
CachedPixelShaderSetting<float> m_saturation_pixel;
CachedPixelShaderSetting<float, 3> m_sun_position_pixel;
CachedPixelShaderSetting<float> m_sun_brightness_pixel;
CachedPixelShaderSetting<float, 3> m_moon_position_pixel;
CachedPixelShaderSetting<float> m_moon_brightness_pixel;
public:
void onSettingsChange(const std::string &name)
@ -461,7 +465,11 @@ public:
m_bloom_intensity_pixel("bloomIntensity"),
m_bloom_strength_pixel("bloomStrength"),
m_bloom_radius_pixel("bloomRadius"),
m_saturation_pixel("saturation")
m_saturation_pixel("saturation"),
m_sun_position_pixel("sunPositionScreen"),
m_sun_brightness_pixel("sunBrightness"),
m_moon_position_pixel("moonPositionScreen"),
m_moon_brightness_pixel("moonBrightness")
{
g_settings->registerChangedCallback("enable_fog", settingsCallback, this);
g_settings->registerChangedCallback("exposure_compensation", settingsCallback, this);
@ -579,6 +587,51 @@ public:
}
float saturation = m_client->getEnv().getLocalPlayer()->getLighting().saturation;
m_saturation_pixel.set(&saturation, services);
// Map directional light to screen space
auto camera_node = m_client->getCamera()->getCameraNode();
core::matrix4 transform = camera_node->getProjectionMatrix();
transform *= camera_node->getViewMatrix();
if (m_sky->getSunVisible()) {
v3f sun_position = camera_node->getAbsolutePosition() +
10000. * m_sky->getSunDirection();
transform.transformVect(sun_position);
sun_position.normalize();
float sun_position_array[3] = { sun_position.X, sun_position.Y, sun_position.Z};
m_sun_position_pixel.set(sun_position_array, services);
float sun_brightness = rangelim(107.143f * m_sky->getSunDirection().dotProduct(v3f(0.f, 1.f, 0.f)), 0.f, 1.f);
m_sun_brightness_pixel.set(&sun_brightness, services);
}
else {
float sun_position_array[3] = { 0.f, 0.f, -1.f };
m_sun_position_pixel.set(sun_position_array, services);
float sun_brightness = 0.f;
m_sun_brightness_pixel.set(&sun_brightness, services);
}
if (m_sky->getMoonVisible()) {
v3f moon_position = camera_node->getAbsolutePosition() +
10000. * m_sky->getMoonDirection();
transform.transformVect(moon_position);
moon_position.normalize();
float moon_position_array[3] = { moon_position.X, moon_position.Y, moon_position.Z};
m_moon_position_pixel.set(moon_position_array, services);
float moon_brightness = rangelim(107.143f * m_sky->getMoonDirection().dotProduct(v3f(0.f, 1.f, 0.f)), 0.f, 1.f);
m_moon_brightness_pixel.set(&moon_brightness, services);
}
else {
float moon_position_array[3] = { 0.f, 0.f, -1.f };
m_moon_position_pixel.set(moon_position_array, services);
float moon_brightness = 0.f;
m_moon_brightness_pixel.set(&moon_brightness, services);
}
}
void onSetMaterial(const video::SMaterial &material) override

@ -171,7 +171,7 @@ RenderStep *addPostProcessing(RenderPipeline *pipeline, RenderStep *previousStep
// get bright spots
u32 shader_id = client->getShaderSource()->getShader("extract_bloom", TILE_MATERIAL_PLAIN, NDT_MESH);
RenderStep *extract_bloom = pipeline->addStep<PostProcessingStep>(shader_id, std::vector<u8> { TEXTURE_COLOR, TEXTURE_EXPOSURE_1 });
RenderStep *extract_bloom = pipeline->addStep<PostProcessingStep>(shader_id, std::vector<u8> { TEXTURE_COLOR, TEXTURE_EXPOSURE_1, TEXTURE_DEPTH });
extract_bloom->setRenderSource(buffer);
extract_bloom->setRenderTarget(pipeline->createOwned<TextureBufferOutput>(buffer, TEXTURE_BLOOM));
source = TEXTURE_BLOOM;