Examples: Use Wendland C2 falloff for sculpt brushes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mrdoob

examples/jsm/sculpt/SculptTools.js

@@ -656,8 +656,7 @@ function decimationPass( mesh, iTris, center, radius2, detail2 ) {
 		else if ( fallOff < radius2 * 2.0 ) {
 
 			fallOff = ( Math.sqrt( fallOff ) - radius ) / ( radius * Math.SQRT2 - radius );
-			const f2 = fallOff * fallOff;
-			fallOff = 3.0 * f2 * f2 - 4.0 * f2 * fallOff + 1.0;
+			fallOff = falloff( fallOff );
 
 		} else continue;
 

examples/jsm/sculpt/SculptUtils.js

@@ -214,8 +214,10 @@ function pointInsideTriangle( point, v1, v2, v3 ) {
 
 function falloff( dist ) {
 
-	const d2 = dist * dist;
-	return 3.0 * d2 * d2 - 4.0 * d2 * dist + 1.0;
+	// Wendland C2 kernel: (1-d)^4 * (4d+1)
+	const t = 1.0 - dist;
+	const t2 = t * t;
+	return t2 * t2 * ( 4.0 * dist + 1.0 );
 
 }