diff --git a/zoneb/bin/data/settings.xml b/zoneb/bin/data/settings.xml
index ac7a4dc..89caf32 100644
--- a/zoneb/bin/data/settings.xml
+++ b/zoneb/bin/data/settings.xml
@@ -3,7 +3,7 @@
 	<XY>54.0816, 3.06123</XY>
 	<scale>1.724</scale>
 	<device>video1</device>
-	<thermo_delay>8</thermo_delay>
+	<thermo_delay>6</thermo_delay>
 	<blend_add>1</blend_add>
 	<render_times>0</render_times>
 	<trace_times>21</trace_times>
diff --git a/zoneb/bin/data/shaders/particles/update.frag b/zoneb/bin/data/shaders/particles/update.frag
index b5daaee..f385b7c 100755
--- a/zoneb/bin/data/shaders/particles/update.frag
+++ b/zoneb/bin/data/shaders/particles/update.frag
@@ -133,14 +133,55 @@ void main()
   vec4 ray11 = texture(u_world, basePix + vec2(1, 1));
 
   float depth0 = mix(depth00, depth10, subPix.x);
+  if(depth00 == 0) depth0 = depth10;
+  if(depth10 == 0) depth0 = depth00;
   float depth1 = mix(depth01, depth11, subPix.x);
+  if(depth01 == 0) depth1 = depth11;
+  if(depth11 == 0) depth1 = depth01;
   vec4 ray0 = mix(ray00, ray10, subPix.x);
   vec4 ray1 = mix(ray01, ray11, subPix.x);
 
   float depth = mix(depth0, depth1, subPix.y);
+  if(depth00 == 0 && depth10 == 0) depth = depth1;
+  if(depth01 == 0 && depth11 == 0) depth = depth0;
   vec4 ray = mix(ray0, ray1, subPix.y);
 
-  float vValid = (depth00 != 0 && depth01 != 0 && depth10 != 0 && depth11 != 0 && ray.x != 0 && ray.y != 0) ? 1 : 0;
+  int validCount = 0;
+  // validCount += (depth00 != 0) ? 1 : 0;
+  // validCount += (depth01 != 0) ? 1 : 0;
+  // validCount += (depth10 != 0) ? 1 : 0;
+  // validCount += (depth11 != 0) ? 1 : 0;
+  // float vValid = (validCount > 1) ? 1 : 0;
+  // if(subPix.x < 0.5 && subPix.y < 0.5) {
+  //   if(depth00 != 0) validCount += 1;
+  // }
+  // else if (subPix.x >= 0.5 && subPix.y < 0.5) {
+  //   if(depth10 != 0) validCount += 1;
+  // }
+  // else if(subPix.x < 0.5 && subPix.y >= 0.5) {
+  //   if(depth01 != 0) validCount += 1;
+  // }
+  // else if (subPix.x >= 0.5 && subPix.y >= 0.5) {
+  //   if(depth11 != 0) validCount += 1;
+  // }
+  // float vValid = (validCount > 0) ? 1 : 0;
+
+  float validity = 0;
+  if(depth00 != 0) {
+    validity += sqrt(2) - length(subPix - vec2(0, 0));
+  }
+  if(depth10 != 0) {
+    validity += sqrt(2) - length(subPix - vec2(1, 0));
+  }
+  if(depth01 != 0) {
+    validity += sqrt(2) - length(subPix - vec2(0, 1));
+  }
+  if(depth11 != 0) {
+    validity += sqrt(2) - length(subPix - vec2(1, 1));
+  }
+
+  float vValid = (validity > 1) ? 1 : 0;
+  // float vValid = (depth00 != 0 && depth01 != 0 && depth10 != 0 && depth11 != 0 && ray.x != 0 && ray.y != 0) ? 1 : 0;
 
   vec4 posWorld = vec4(1);
   posWorld.z = -depth * 65535.0; // Remap to float range.
@@ -173,7 +214,11 @@ void main()
     thermo = misc.x;
   }
   else { // wandering
-    age += 10.1;
+    age += 0.04;
+    vec3 rand = random3(vec3(texCoordVarying.st, 0));
+    if(mod(subPix.x + rand.x, 0.5) > 0.1 || mod(subPix.y + rand.y, 0.5) > 0.1) {
+      age += 10.1;
+    }
     thermo = misc.x;
   }
 
@@ -189,7 +234,7 @@ void main()
     force.x += cos(th) * cos(phi);
     force.y += sin(th) * cos(phi);
     force.z += sin(phi);
-    force *= 100;
+    force *= 300;
   }
   else {
     float th = 3.1415 * 4 * simplex3d_fractal(vec3(pos.xyz * 0.01));
diff --git a/zoneb/src/ofApp.cpp b/zoneb/src/ofApp.cpp
index 3320106..f2d1d4d 100644
--- a/zoneb/src/ofApp.cpp
+++ b/zoneb/src/ofApp.cpp
@@ -131,7 +131,7 @@ void ofApp::setupGui()
 {
   gui.setup("ZONE B", "settings.xml"); // most of the time you don't need a name
   gui.add(registrationXY.setup("XY", {-9, -9}, {-100, -100}, {100, 100}));
-  gui.add(registrationScale.setup("scale", 2.0, 0.1, 3));
+  gui.add(registrationScale.setup("scale", 2.0, 1.5, 2));
   gui.add(v4l2Delay.setup("thermo delay", 0, 0, 59));
   gui.add(captureDeviceName.setup("device", "video3"));
   gui.add(blendAdd.setup("blend add", false));