diff --git a/dev.sh b/dev.sh
index 7ddb5b6..03b5145 100755
--- a/dev.sh
+++ b/dev.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 echo "🛁 Cleaning up build and output"
-rm -rf build
+# rm -rf build
 rm -rf output
 ./build.sh
 
diff --git a/trees/math-000K.tree b/trees/math-000K.tree
index c3dbe01..e12713f 100644
--- a/trees/math-000K.tree
+++ b/trees/math-000K.tree
@@ -24,6 +24,8 @@
 #define RAYMARCH_AMBIENT    vec3(0.7, 0.9, 1.0)
 // #define RAYMARCH_AMBIENT    vec3(0.374,0.481,0.535)
 
+#define EPSILON 0.0001
+
 #include "lygia/space/ratio.glsl"
 #include "lygia/sdf.glsl"
 #include "lygia/lighting/raymarch.glsl"
@@ -58,11 +60,15 @@ float mySDF2(vec3 p) {
     float z2 = pow(z, 2.);
     float y3 = pow(y, 3.);
     
-    return 5.*(z2+y3-y4-x2*y2);
+    // return 5.*(z2+y3-y4-x2*y2);
 
     // return (y2-x2-z2);
 
-    // return (x2-z2*y2+y3);
+    return (x2-z2*y2+y3);
+}
+
+float tapping_abs(float x) {
+    return max(-0.01 * x, x);
 }
 
 Material raymarchMap( in vec3 pos ) {
@@ -77,7 +83,7 @@ Material raymarchMap( in vec3 pos ) {
 
     // res = opUnion(res, materialNew( vec3(1.0, 2.0, 1.0), opIntersection(0.05 * abs(mySDF2(pos)), cubeSDF(pos, 1.0))) );
     
-    Material res = materialNew( vec3(1.0, 2.0, 1.0), opIntersection(0.05 * abs(mySDF2(pos)), sphereSDF(pos, 1.8)));
+    Material res = materialNew( vec3(1.0, 2.0, 1.0), opIntersection(0.05 * tapping_abs(mySDF2(pos)), sphereSDF(pos, 1.8)));
 
     // res = opUnion( res, materialNew( vec3(1.0, 1.0, 1.0), 1.0, 0.0, sphereSDF(pos-vec3( 0.0, 2.0, 0.0), 0.5 ) ) );
     // res = opUnion( res, materialNew( vec3(0.0, 1.0, 1.0), boxSDF(      pos-vec3( 2.0, 0.5, 0.0), vec3(0.4, 0.4, 0.4) ) ) );