diff --git a/generate_animation.sh b/generate_animation.sh
index d30b8c6..81a61f3 100755
--- a/generate_animation.sh
+++ b/generate_animation.sh
@@ -8,4 +8,4 @@ rm out/step00000.pnm
 # convert all to PNG
 parallel --jobs 8 "pnmtopng {} > {.}.png" ::: out/*.pnm
 # generate video
-ffmpeg -y -framerate 30 -pattern_type glob -i 'out/*.png' -r 30 -vf scale=500:-1 -loop 0 out.mp4
+ffmpeg -y -framerate 30 -pattern_type glob -i 'out/*.png' -r 30 -vf scale=500:-1 out.mp4
diff --git a/grayscott.bqn b/grayscott.bqn
index 2d37624..24b2a71 100644
--- a/grayscott.bqn
+++ b/grayscott.bqn
@@ -4,7 +4,7 @@
 # Parameters
 dt‿da‿db‿f‿k←⟨1.0,0.16,0.08,0.060,0.062⟩
 n←500  # image size
-m←10  # seed size at the center of the image
+m←150  # seed size at the center of the image
 
 # Discrete Laplacian
 Lapl←(+´∘∾1‿¯1(⌽⋈⌽˘)¨<)-4⊸×
@@ -15,15 +15,16 @@ Update←(UpdateA⋈UpdateB)´
 
 # Initialization
 a←n‿n⥊1
-Mask←{𝕩‿𝕩↑(-𝕨‿𝕨+𝕩÷2)↑(2×𝕨‿𝕨)⥊1}
-b←(m Mask n)⌈0.1×n‿n•rand.Range 0
+SquareMask←{𝕩‿𝕩↑(-𝕨‿𝕨+𝕩÷2)↑(2×𝕨‿𝕨)⥊1}
+CircleMask←{(𝕨×𝕨)≥(⌽∘⍉∾⍉)(⌽∾⊢)+○(⋆⟜2)⌜˜↕𝕩÷2}
+mask←(n‿n•rand.Range 2)×m CircleMask n
+b←mask⌈0.05×n‿n•rand.Range 0
 
 # Run
 Step←{stepsize 𝕊 i‿a‿b:
-  •term.OutRaw"."
-  •term.Flush @
+  •Show i×stepsize
   ap‿bp←Update⍟stepsize a‿b
-  ("out/step"∾(¯5↑∾•Fmt¨5-⊸↑i)∾".pnm")•file.Chars (PPM ⌊255×>Inferno¨1-a)∾@+10
+  ("out/step"∾(¯5↑∾•Fmt¨5-⊸↑i)∾".pnm")•file.Chars (PPM ⌊255×>Viridis¨1-a)∾@+10
   (i+1)‿ap‿bp
 }