Add density to volumetric fog

Popov72 · Dec 19, 2019 · d14dafe · d14dafe
1 parent 680ca4a
commit d14dafe
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Showing 2 changed files with 65 additions and 2 deletions.
diff --git a/resources/shader/TR_volumetric_fog.fs b/resources/shader/TR_volumetric_fog.fs
@@ -52,8 +52,9 @@ void main() {
         }
         float distToCenter = length(cross(volFogCenter - vwCamPos, dir));
         float fr = distToCenter < volFogRadius ? smoothstep(0.0, 1.0, cos(distToCenter/volFogRadius*3.141592/2.0)) : 0.0;
-        //float fr = distToCenter < volFogRadius ? smoothstep(0.0, 1.0, 1.0-distToCenter/volFogRadius) : 0.0;
-        glFragColor = mix(glFragColor, vec4(volFogColor, glFragColor.a), clamp(dist/(volFogRadius*2.0)*fr, 0.0, 1.0));
+        float e = dist/(volFogRadius*2.0);
+        e = 1.0 - exp(-e * 4.0);
+        glFragColor = mix(glFragColor, vec4(volFogColor, glFragColor.a), clamp(e*fr, 0.0, 1.0));
     }
 
     if (useFog == 1) {

diff --git a/resources/shader/TR_volumetric_fog_ noconditional.fs b/resources/shader/TR_volumetric_fog_ noconditional.fs
@@ -0,0 +1,62 @@
+#version 300 es
+precision highp float;
+
+const vec3  fogColor = vec3(0.0, 0.0, 0.0);
+const float fogNear = 14000.0;
+const float fogFar = 21000.0;
+
+uniform int useFog;
+uniform sampler2D map;
+uniform sampler2D mapBump;
+uniform vec4 offsetBump;
+
+uniform vec3 volFogCenter;
+uniform float volFogRadius;
+uniform vec3 volFogColor;
+
+in vec3 vColor;
+in vec2 vUv;
+in vec4 vwPos;
+in vec3 vwCamPos;
+
+out vec4 glFragColor;
+
+void main() {
+	vec4 texelColor = texture( map, vUv );
+    if (offsetBump.w == 1.0) {
+        vec4 bumpColor = texture( mapBump, vUv + offsetBump.xy);
+        float a = texelColor.a;
+        texelColor = texelColor * (bumpColor + 0.25) * 1.25;
+    	texelColor.a = a;
+    }
+	glFragColor = texelColor;
+
+	if ( glFragColor.a < 0.5 ) discard;
+	glFragColor = glFragColor * vec4( vColor, 1.0 );
+
+    float volFogRadius2 = volFogRadius * volFogRadius;
+    float distCamToPos = distance(vwPos.xyz, vwCamPos);
+    vec3 dir = normalize(vwPos.xyz - vwCamPos);
+    vec3 L = volFogCenter - vwCamPos;
+    float tca = dot(L, dir);
+    float d2 = dot(L, L) - tca * tca;
+
+    float thc = sqrt(max(volFogRadius2 - d2, 0.0));
+    float t0 = tca - thc;
+    float t1 = tca + thc;
+    float dist =  mix(0.0, min(distCamToPos, t1), max(sign(-t0), 0.0)*max(sign(t1), 0.0))
+                + mix(0.0, min(distCamToPos, t1) - t0, max(sign(t0), 0.0)*max(sign(t1), 0.0)*max(sign(distCamToPos - t0), 0.0));
+    float distToCenter = length(cross(volFogCenter - vwCamPos, dir));
+    float fr = smoothstep(0.0, 1.0, cos(distToCenter/volFogRadius*3.141592/2.0));
+    float e = dist/(volFogRadius*2.0);
+    e = 1.0 - exp(-e * 4.0);
+    vec4 glFragColorWithFog = mix(glFragColor, vec4(volFogColor, glFragColor.a), e*fr, 0.0, 1.0));
+
+    glFragColor = mix(glFragColor, glFragColorWithFog, max(sign(volFogRadius2 - d2), 0.0));
+
+    if (useFog == 1) {
+        float depth = gl_FragCoord.z / gl_FragCoord.w;
+        float fogFactor = smoothstep( fogNear, fogFar, depth );
+        glFragColor = mix( glFragColor, vec4( fogColor, glFragColor.w ), fogFactor );
+    }
+}