Minor changes

client/shaders/clouds_merge/opengl_fragment.glsl

@@ -48,6 +48,9 @@ vec4 sampleClouds(vec2 uv) {
 }
 
 vec4 getClouds(vec2 uv) {
+#if (VOLUMETRICS_UNDERSAMPLING <= 1)
+		return sampleClouds(uv);
+#else
 	return
 		sampleClouds(uv - texelSize0 * vec2(-1.0, -1.0)) / 9.0 +
 		sampleClouds(uv - texelSize0 * vec2( 0.0, -1.0)) / 9.0 +
@@ -58,6 +61,7 @@ vec4 getClouds(vec2 uv) {
 		sampleClouds(uv - texelSize0 * vec2(-1.0,  1.0)) / 9.0 +
 		sampleClouds(uv - texelSize0 * vec2( 0.0,  1.0)) / 9.0 +
 		sampleClouds(uv - texelSize0 * vec2( 1.0,  1.0)) / 9.0;
+#endif
 }
 
 void main(void)

client/shaders/nodes_shader/opengl_fragment.glsl

@@ -8,6 +8,8 @@
 uniform sampler2D baseTexture;
 uniform vec2 texelSize0;
 
+varying vec3 sunTint;
+
 uniform vec3 dayLight;
 uniform lowp vec4 fogColor;
 uniform float fogDistance;
@@ -485,7 +487,7 @@ void main(void)
 		// calculate fragment color from components:
 		col.rgb =
 				adjusted_night_ratio * col.rgb + // artificial light
-				(1.0 - adjusted_night_ratio) * ( // natural light
+				sunTint * (1.0 - adjusted_night_ratio) * ( // natural light
 						col.rgb * (1.0 - shadow_int * (1.0 - shadow_color)) +  // filtered texture color
 						dayLight * shadow_color * shadow_int);                 // reflected filtered sunlight/moonlight
 	}

client/shaders/nodes_shader/opengl_vertex.glsl

@@ -45,6 +45,7 @@ varying float area_enable_parallax;
 
 varying highp vec3 eyeVec;
 varying float nightRatio;
+varying vec3 sunTint;
 // Color of the light emitted by the light sources.
 uniform vec3 artificialLight;
 const float e = 2.718281828459;
@@ -145,8 +146,19 @@ float snoise(vec3 p)
 
 #endif
 
+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.))));
+}
 
 void main(void)
 {
@@ -259,6 +271,7 @@ void main(void)
 		shadow_position.z -= z_bias;
 		perspective_factor = pFactor;
 
+		sunTint = vec3(1.0);
 		if (f_timeofday < 0.21) {
 			adj_shadow_strength = f_shadow_strength * 0.5 *
 				(1.0 - mtsmoothstep(0.18, 0.21, f_timeofday));
@@ -269,6 +282,7 @@ void main(void)
 			adj_shadow_strength = f_shadow_strength *
 				mtsmoothstep(0.21, 0.26, f_timeofday) *
 				(1.0 - mtsmoothstep(0.743, 0.793, f_timeofday));
+			sunTint = mix(vec3(1.0), getDirectLightScatteringAtGround(v_LightDirection), min(1.0, 4.0 * adj_shadow_strength));
 		}
 	}
 #endif

client/shaders/object_shader/opengl_fragment.glsl

@@ -1,5 +1,6 @@
 uniform sampler2D baseTexture;
 
+varying vec3 sunTint;
 uniform vec3 dayLight;
 uniform lowp vec4 fogColor;
 uniform float fogDistance;
@@ -431,7 +432,7 @@ void main(void)
 		// calculate fragment color from components:
 		col.rgb =
 				adjusted_night_ratio * col.rgb + // artificial light
-				(1.0 - adjusted_night_ratio) * ( // natural light
+				sunTint * (1.0 - adjusted_night_ratio) * ( // natural light
 						col.rgb * (1.0 - shadow_int * (1.0 - shadow_color)) +  // filtered texture color
 						dayLight * shadow_color * shadow_int);                 // reflected filtered sunlight/moonlight
 	}

client/shaders/object_shader/opengl_vertex.glsl

@@ -32,6 +32,7 @@ centroid varying vec2 varTexCoord;
 
 varying highp vec3 eyeVec;
 varying float nightRatio;
+varying vec3 sunTint;
 // Color of the light emitted by the light sources.
 uniform vec3 artificialLight;
 varying float vIDiff;
@@ -89,6 +90,20 @@ float directional_ambient(vec3 normal)
 	return dot(v, vec3(0.670820, 1.000000, 0.836660));
 }
 
+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.))));
+}
+
 void main(void)
 {
 	varTexCoord = (mTexture * inTexCoord0).st;
@@ -162,6 +177,7 @@ void main(void)
 		shadow_position.z -= z_bias;
 		perspective_factor = pFactor;
 
+		sunTint = vec3(1.0);
 		if (f_timeofday < 0.21) {
 			adj_shadow_strength = f_shadow_strength * 0.5 *
 				(1.0 - mtsmoothstep(0.18, 0.21, f_timeofday));
@@ -172,6 +188,7 @@ void main(void)
 			adj_shadow_strength = f_shadow_strength *
 				mtsmoothstep(0.21, 0.26, f_timeofday) *
 				(1.0 - mtsmoothstep(0.743, 0.793, f_timeofday));
+			sunTint = mix(vec3(1.0), getDirectLightScatteringAtGround(v_LightDirection), min(1.0, 4.0 * adj_shadow_strength));
 		}
 	}
 #endif

client/shaders/volumetric_clouds/opengl_fragment.glsl

@@ -137,10 +137,15 @@ void main(void)
 	float bottomPlaneIntersect = clamp((cloudHeight - cameraPosition.y) / viewVec.y, 0., 4. * fogDistance);
 	float topPlaneIntersect = clamp((cloudHeight + cloudThickness - cameraPosition.y) / viewVec.y, 0., 4. * fogDistance);
 
+#if (VOLUMETRICS_UNDERSAMPLING <= 1)
+	bottomPlaneIntersect = min(depth, bottomPlaneIntersect);
+	topPlaneIntersect = min(depth, topPlaneIntersect);
+#else
 	if ((bottomPlaneIntersect > depth + 5.0) != (topPlaneIntersect > depth + 5.0)) {
 		bottomPlaneIntersect = min(depth, bottomPlaneIntersect);
 		topPlaneIntersect = min(depth, topPlaneIntersect);
 	}
+#endif
 
 	float startDepth = min(bottomPlaneIntersect, topPlaneIntersect);
 	float endDepth = max(bottomPlaneIntersect, topPlaneIntersect);

src/client/render/secondstage.cpp

@@ -26,6 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "settings.h"
 #include "noise.h"
 
+// TODO: Probably this could still be improved, having a step for this seems silly
 class NoiseStep : public RenderStep {
 public:
 	NoiseStep(TextureBuffer* buffer, u8 id, u32 size) :

src/client/shader.cpp

@@ -728,6 +728,10 @@ ShaderInfo ShaderSource::generateShader(const std::string &name,
 		shaders_header << "#define VOLUMETRIC_LIGHT 1\n";
 	}
 
+	if (g_settings->getBool("enable_volumetric_clouds")) {
+		shaders_header << "#define VOLUMETRICS_UNDERSAMPLING " << g_settings->getU32("volumetrics_undersampling") << '\n';
+	}
+
 	shaders_header << "#line 0\n"; // reset the line counter for meaningful diagnostics
 
 	std::string common_header = shaders_header.str();