Deeper shadows and fog/snow continuity across terrain tiles for highest quality level terrain shader of Atmospheric Light Scattering

Shaders/terrain-haze-ultra.frag

@@ -4,12 +4,11 @@
 // Ambient term comes in gl_Color.rgb.
 varying vec4 diffuse_term;
 varying vec3 normal;
-//varying vec2 nvec;
 varying vec3 relPos;
 varying vec2 rawPos;
-//varying vec2 worldPos;
+varying vec3 worldPos;
 varying vec3 ecViewdir;
-varying vec3 ecNormal;
+
 
 
 uniform sampler2D texture;
@@ -20,7 +19,7 @@ uniform sampler2D mix_texture;
 uniform sampler2D grain_texture;
 uniform sampler2D dot_texture;
 uniform sampler2D gradient_texture;
-//uniform sampler2D foam_texture;
+
 
 
 //varying float yprime_alt;
@@ -71,6 +70,10 @@ float rand2D(in vec2 co){
     return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
 }
 
+float rand3D(in vec3 co){
+    return fract(sin(dot(co.xyz ,vec3(12.9898,78.233,144.7272))) * 43758.5453);
+}
+
 float cosine_interpolate(in float a, in float b, in float x)
 {
 	float ft = x * 3.1415927;
@@ -103,6 +106,39 @@ float interpolatedNoise2D(in float x, in float y)
       return simple_interpolate(i1 , i2 , fractional_y);
 }
 
+float interpolatedNoise3D(in float x, in float y, in float z)
+{
+      float integer_x    = x - fract(x);
+      float fractional_x = x - integer_x;
+
+      float integer_y    = y - fract(y);
+      float fractional_y = y - integer_y;
+
+      float integer_z    = z - fract(z);
+      float fractional_z = z - integer_z;
+
+      float v1 = rand3D(vec3(integer_x, integer_y, integer_z));
+      float v2 = rand3D(vec3(integer_x+1.0, integer_y, integer_z));
+      float v3 = rand3D(vec3(integer_x, integer_y+1.0, integer_z));
+      float v4 = rand3D(vec3(integer_x+1.0, integer_y +1.0, integer_z));
+
+      float v5 = rand3D(vec3(integer_x, integer_y, integer_z+1.0));
+      float v6 = rand3D(vec3(integer_x+1.0, integer_y, integer_z+1.0));
+      float v7 = rand3D(vec3(integer_x, integer_y+1.0, integer_z+1.0));
+      float v8 = rand3D(vec3(integer_x+1.0, integer_y +1.0, integer_z+1.0));
+
+
+      float i1 = simple_interpolate(v1,v5, fractional_z);
+      float i2 = simple_interpolate(v2,v6, fractional_z);
+      float i3 = simple_interpolate(v3,v7, fractional_z);
+      float i4 = simple_interpolate(v4,v8, fractional_z);
+
+      float ii1 = simple_interpolate(i1,i2,fractional_x);
+      float ii2 = simple_interpolate(i3,i4,fractional_x);
+ 
+
+      return simple_interpolate(ii1 , ii2 , fractional_y);
+}
 
 
 float Noise2D(in vec2 coord, in float wavelength)
@@ -111,6 +147,11 @@ return interpolatedNoise2D(coord.x/wavelength, coord.y/wavelength);
 
 }
 
+float Noise3D(in vec3 coord, in float wavelength)
+{
+return interpolatedNoise3D(coord.x/wavelength, coord.y/wavelength, coord.z/wavelength);
+}
+
 float dotNoise2D(in float x, in float y, in float fractionalMaxDotSize)
 {
 	float integer_x    = x - fract(x);
@@ -259,10 +300,10 @@ float noise_25m = Noise2D(rawPos.xy, 25.0);
 float noise_50m = Noise2D(rawPos.xy, 50.0);
 
 
-float noise_250m = Noise2D(rawPos.xy,250.0);
-float noise_500m = Noise2D(rawPos.xy, 500.0);
-float noise_1500m = Noise2D(rawPos.xy, 1500.0);
-float noise_2000m = Noise2D(rawPos.xy, 2000.0);
+float noise_250m = Noise3D(worldPos.xyz,250.0);
+float noise_500m = Noise3D(worldPos.xyz, 500.0);
+float noise_1500m = Noise3D(worldPos.xyz, 1500.0);
+float noise_2000m = Noise3D(worldPos.xyz, 2000.0);
 
 // dot noise
 

Shaders/terrain-haze-ultra.vert

@@ -20,14 +20,12 @@
 // bugs with gl_FrontFacing in the fragment shader.
 varying vec4 diffuse_term;
 varying vec3 normal;
-//varying vec2 nvec;
 varying vec3 relPos;
 varying vec2 rawPos;
-//varying vec2 worldPos;
+varying vec3 worldPos;
 varying vec3 ecViewdir;
 
-//varying float earthShade;
-//varying float yprime_alt;
+
 varying float mie_angle;
 varying float steepness;
 varying float grad_dir;
@@ -42,15 +40,13 @@ uniform float visibility;
 uniform float overcast;
 uniform float ground_scattering;
 uniform float eye_alt;
-//uniform float eye_lat;
-//uniform float eye_lon;
 uniform float moonlight;
 
 uniform mat4 osg_ViewMatrixInverse;
 
 float earthShade;
 float yprime_alt;
-//float mie_angle;
+
 
 
 // This is the value used in the skydome scattering shader - use the same here for consistency?
@@ -85,17 +81,8 @@ void main()
   float scattering;
 
    rawPos = gl_Vertex.xy;
+   worldPos = (osg_ViewMatrixInverse *gl_ModelViewMatrix * gl_Vertex).xyz;
 	
-	// try making a continuous coordinate system
-	//vec4 worldPos3D = (osg_ViewMatrixInverse *gl_ModelViewMatrix * gl_Vertex);
-
-	//rawPos = worldPos3d.yz;
-	//float x1 = sin(eye_lon) * worldPos3D.y + cos(eye_lon) * worldPos3D.z;
-	//float y1 = cos(eye_lon) * worldPos3D.y - sin(eye_lon) * worldPos3D.z;
-	
-	//y1 = cos(eye_lat) * y1 + sin(eye_lat) * worldPos3D.x;
-	
-	//worldPos = vec2 (x1, y1);
 	
    steepness = dot(normalize(gl_Normal), vec3 (0.0, 0.0, 1.0));
    grad_dir = dot(normalize(gl_Normal.xy), vec2 (1.0, 0.0));
@@ -277,7 +264,12 @@ else // the faster, full-day version without lightfields
 
 light_ambient = light_ambient * ((1.0+steepness)/2.0 * 1.2 + (1.0-steepness)/2.0 * 0.2);
 
-//light_ambient.rgb = 0.1 * light_ambient.rgb;
+// deeper shadows when there is lots of direct light
+
+float shade_depth =  1.0 * smoothstep (0.6,0.95,ground_scattering) * (1.0-smoothstep(0.1,0.5,overcast)) * smoothstep(0.4,1.5,earthShade);
+
+   light_ambient.rgb = light_ambient.rgb * (1.0 - shade_depth);
+   light_diffuse.rgb = light_diffuse.rgb * (1.0 + 1.2 * shade_depth);
 
 // default lighting based on texture and material using the light we have just computed