diff --git a/src/main/c/velocitystep.c b/src/main/c/velocitystep.c
index 6b46d20..579ce05 100644
--- a/src/main/c/velocitystep.c
+++ b/src/main/c/velocitystep.c
@@ -415,6 +415,7 @@ void advect(JNIEnv * env, uint32_t chunk_mask, int N, int b, jobjectArray jrd, f
     for(k=1; k<N-1; k++){
         for(j=1; j<N-1; j++){
             for(i=1; i<N-1; i++){
+                sampleArr = d0;
                 //calculate location to pull from
                 x = i-dtx*u[IX(i,j,k)];
                 y = j-dty*v[IX(i,j,k)];
@@ -531,11 +532,39 @@ JNIEXPORT void JNICALL Java_electrosphere_FluidSim_setBoundsToNeighbors
   jobjectArray neighborArray){
     int DIM = N;
     float * target = GET_ARR(env,neighborArray,CENTER_LOC);
+    float * source;
+    // if(ARR_EXISTS(chunk_mask,0,1,1)){
+    //     source = GET_ARR(env,neighborArray,CK(0,1,1));
+    //     for(int x=1; x < DIM-1; x++){
+    //         for(int y = 1; y < DIM-1; y++){
+    //             target[IX(0,x,y)] = source[IX(DIM-2,x,y)];
+    //         }
+    //     }
+    // } else {
+        for(int x=1; x < DIM-1; x++){
+            for(int y = 1; y < DIM-1; y++){
+                target[IX(0,x,y)] = vector_dir==BOUND_DIR_U ? -target[IX(1,x,y)] : target[IX(1,x,y)];
+            }
+        }
+    // }
+
+    // if(ARR_EXISTS(chunk_mask,2,1,1)){
+    //     source = GET_ARR(env,neighborArray,CK(2,1,1));
+    //     for(int x=1; x < DIM-1; x++){
+    //         for(int y = 1; y < DIM-1; y++){
+    //             target[IX(DIM-1,x,y)] = source[IX(1,x,y)];
+    //         }
+    //     }
+    // } else {
+        for(int x=1; x < DIM-1; x++){
+            for(int y = 1; y < DIM-1; y++){
+                target[IX(DIM-1,x,y)] =     vector_dir==BOUND_DIR_U ? -target[IX(DIM-2,x,y)] : target[IX(DIM-2,x,y)];
+            }
+        }
+    // }
     for(int x=1; x < DIM-1; x++){
         for(int y = 1; y < DIM-1; y++){
             //((x)+(DIM)*(y) + (DIM)*(DIM)*(z))
-            target[IX(0,x,y)] =         vector_dir==BOUND_DIR_U ? -target[IX(1,x,y)] : target[IX(1,x,y)];
-            target[IX(DIM-1,x,y)] =     vector_dir==BOUND_DIR_U ? -target[IX(DIM-2,x,y)] : target[IX(DIM-2,x,y)];
             target[IX(x,0,y)] =         vector_dir==BOUND_DIR_V ? -target[IX(x,1,y)] : target[IX(x,1,y)];
             target[IX(x,DIM-1,y)] =     vector_dir==BOUND_DIR_V ? -target[IX(x,DIM-2,y)] : target[IX(x,DIM-2,y)];
             target[IX(x,y,0)] =         vector_dir==BOUND_DIR_W ? -target[IX(x,y,1)] : target[IX(x,y,1)];