diff --git a/src/core/shaders.ts b/src/core/shaders.ts
index 09ef681..869f774 100644
--- a/src/core/shaders.ts
+++ b/src/core/shaders.ts
@@ -172,7 +172,7 @@ export const displayShader = /* glsl */ `
     float obs      = texture2D(uObstacle,  vUv).r;
     // Smooth fade: density falls off over the blurred obstacle boundary zone
     // rather than cutting off at a hard step, eliminating the jagged fringe.
-    float density  = max(texture2D(uTexture, vUv).r, 0.0) * (1.0 - obs);
+    float density  = clamp(texture2D(uTexture, vUv).r, 0.0, 1.0) * (1.0 - obs);
     float coverage = texture2D(uCoverage,  vUv).r;
 
     // 8-tap Sobel normal — computes gradient via 3×3 kernel (no centre sample needed).
@@ -180,14 +180,14 @@ export const displayShader = /* glsl */ `
     // ≈ 3 sim texels per axis.  The Sobel kernel properly averages the gradient in
     // every direction — no 4-tap cross bias that creates 45° circuit-board artefacts.
     float sx = texelSize.x * 6.0, sy = texelSize.y * 6.0;
-    float d00 = max(texture2D(uTexture, vUv + vec2(-sx, -sy)).r, 0.0);
-    float d10 = max(texture2D(uTexture, vUv + vec2(0.0, -sy)).r, 0.0);
-    float d20 = max(texture2D(uTexture, vUv + vec2( sx, -sy)).r, 0.0);
-    float d01 = max(texture2D(uTexture, vUv + vec2(-sx, 0.0)).r, 0.0);
-    float d21 = max(texture2D(uTexture, vUv + vec2( sx, 0.0)).r, 0.0);
-    float d02 = max(texture2D(uTexture, vUv + vec2(-sx,  sy)).r, 0.0);
-    float d12 = max(texture2D(uTexture, vUv + vec2(0.0,  sy)).r, 0.0);
-    float d22 = max(texture2D(uTexture, vUv + vec2( sx,  sy)).r, 0.0);
+    float d00 = clamp(texture2D(uTexture, vUv + vec2(-sx, -sy)).r, 0.0, 1.0);
+    float d10 = clamp(texture2D(uTexture, vUv + vec2(0.0, -sy)).r, 0.0, 1.0);
+    float d20 = clamp(texture2D(uTexture, vUv + vec2( sx, -sy)).r, 0.0, 1.0);
+    float d01 = clamp(texture2D(uTexture, vUv + vec2(-sx, 0.0)).r, 0.0, 1.0);
+    float d21 = clamp(texture2D(uTexture, vUv + vec2( sx, 0.0)).r, 0.0, 1.0);
+    float d02 = clamp(texture2D(uTexture, vUv + vec2(-sx,  sy)).r, 0.0, 1.0);
+    float d12 = clamp(texture2D(uTexture, vUv + vec2(0.0,  sy)).r, 0.0, 1.0);
+    float d22 = clamp(texture2D(uTexture, vUv + vec2( sx,  sy)).r, 0.0, 1.0);
     float gx  = (d20 + 2.0*d21 + d22) - (d00 + 2.0*d01 + d02);
     float gy  = (d02 + 2.0*d12 + d22) - (d00 + 2.0*d10 + d20);
 
diff --git a/src/core/wgsl-shaders.ts b/src/core/wgsl-shaders.ts
index d36a27b..008ba0c 100644
--- a/src/core/wgsl-shaders.ts
+++ b/src/core/wgsl-shaders.ts
@@ -313,19 +313,19 @@ struct U {
 
 @fragment fn fs(i: VSOut) -> @location(0) vec4f {
   let obs     = textureSample(uObs, samp, i.uv).r;
-  let density = max(textureSample(uTex, samp, i.uv).r, 0.0) * (1.0 - obs);
+  let density = clamp(textureSample(uTex, samp, i.uv).r, 0.0, 1.0) * (1.0 - obs);
   let cov     = textureSample(uCov, samp, i.uv).r;
 
   let sx  = u.texelSize.x * 6.0;
   let sy  = u.texelSize.y * 6.0;
-  let d00 = max(textureSample(uTex, samp, i.uv + vec2f(-sx, -sy)).r, 0.0);
-  let d10 = max(textureSample(uTex, samp, i.uv + vec2f(0.0, -sy)).r, 0.0);
-  let d20 = max(textureSample(uTex, samp, i.uv + vec2f( sx, -sy)).r, 0.0);
-  let d01 = max(textureSample(uTex, samp, i.uv + vec2f(-sx, 0.0)).r, 0.0);
-  let d21 = max(textureSample(uTex, samp, i.uv + vec2f( sx, 0.0)).r, 0.0);
-  let d02 = max(textureSample(uTex, samp, i.uv + vec2f(-sx,  sy)).r, 0.0);
-  let d12 = max(textureSample(uTex, samp, i.uv + vec2f(0.0,  sy)).r, 0.0);
-  let d22 = max(textureSample(uTex, samp, i.uv + vec2f( sx,  sy)).r, 0.0);
+  let d00 = clamp(textureSample(uTex, samp, i.uv + vec2f(-sx, -sy)).r, 0.0, 1.0);
+  let d10 = clamp(textureSample(uTex, samp, i.uv + vec2f(0.0, -sy)).r, 0.0, 1.0);
+  let d20 = clamp(textureSample(uTex, samp, i.uv + vec2f( sx, -sy)).r, 0.0, 1.0);
+  let d01 = clamp(textureSample(uTex, samp, i.uv + vec2f(-sx, 0.0)).r, 0.0, 1.0);
+  let d21 = clamp(textureSample(uTex, samp, i.uv + vec2f( sx, 0.0)).r, 0.0, 1.0);
+  let d02 = clamp(textureSample(uTex, samp, i.uv + vec2f(-sx,  sy)).r, 0.0, 1.0);
+  let d12 = clamp(textureSample(uTex, samp, i.uv + vec2f(0.0,  sy)).r, 0.0, 1.0);
+  let d22 = clamp(textureSample(uTex, samp, i.uv + vec2f( sx,  sy)).r, 0.0, 1.0);
   let gx  = (d20 + 2.0*d21 + d22) - (d00 + 2.0*d01 + d02);
   let gy  = (d02 + 2.0*d12 + d22) - (d00 + 2.0*d10 + d20);