Vesi efekti

shader.glsl

@@ -24,11 +24,49 @@ float smax( float a, float b, float k )
     return max(a, b) + h*h*0.25/k;
 }
 
+float hash(vec2 p)
+{
+    p  = 50.*fract( p*0.3183099);
+    return fract( p.x*p.y*(p.x+p.y) );
+}
+
+float noise( in vec2 p )
+{
+    vec2 i = floor( p );
+    vec2 f = fract( p );
+	vec2 u = f*f*(3.0-2.0*f);
+    return -0.2+0.2*mix( mix( hash( i + vec2(0.0,0.0) ), 
+                              hash( i + vec2(1.0,0.0) ), u.x),
+                         mix( hash( i + vec2(0.0,1.0) ), 
+                              hash( i + vec2(1.0,1.0) ), u.x), u.y);
+}
+
+
+float displacement( vec3 p )
+{
+    return noise(10.*p.xy+u_time) + 0.5*noise(10.*(p.xy+2.0)-u_time);
+}
 
 /////////////////
 //   GEOMETRY  //
 /////////////////
 
+float sdCylinder(vec3 p, vec3 a, vec3 b, float r)
+{
+    vec3  ba = b - a;
+    vec3  pa = p - a;
+    float baba = dot(ba,ba);
+    float paba = dot(pa,ba);
+    float x = length(pa*baba-ba*paba) - r*baba;
+    float y = abs(paba-baba*0.5)-baba*0.5;
+    float x2 = x*x;
+    float y2 = y*y*baba;
+    
+    float d = (max(x,y)<0.0)?-min(x2,y2):(((x>0.0)?x2:0.0)+((y>0.0)?y2:0.0));
+    
+    return sign(d)*sqrt(abs(d))/baba;
+}
+
 float sdBox( in vec2 p, in vec2 r )
 {
     return length( max(abs(p)-r,0.0) );
@@ -201,6 +239,21 @@ vec2 map( in vec3 p)
         stepDist += stepHeight * 2.0;
     }
 
+    float water = 1000.;
+    if (u_time > 2.0){
+        float cylinder1 = sdCylinder ( p, vec3(0.,0.,0.0), vec3(0.,0.,-0.01), 1.6);
+        float cylinder2 = sdCylinder ( p, vec3(0.,0.,1.), vec3(0.,0.,-1), (2. - (u_time*2.0 - 2.0*2.0)));
+        float cylinder3 = sdCylinder ( p, vec3(0.,0.,1.), vec3(0.,0.,-1.), 1.6);
+        float disp = 0.;
+        if (u_time > 5.0){
+            disp = displacement(p+4.)*min(((u_time-5.0)*0.5), 0.25);
+        }
+        cylinder1 = cylinder1 + disp;
+        water = max(-cylinder2, cylinder1);
+        water = max(water, cylinder3);
+    }    
+    d = min(d, water);
+
     return vec2( d );
 }