MathNode: New `cbrt` Function for Easy Cube Root Calculations (#27497)

* add cbrt

* Move to TSL only

---------

Co-authored-by: sunag <[email protected]>

examples/jsm/nodes/Nodes.js

@@ -39,7 +39,7 @@ import * as NodeUtils from './core/NodeUtils.js';
 export { NodeUtils };
 
 // math
-export { default as MathNode, EPSILON, INFINITY, radians, degrees, exp, exp2, log, log2, sqrt, inverseSqrt, floor, ceil, normalize, fract, sin, cos, tan, asin, acos, atan, abs, sign, length, negate, oneMinus, dFdx, dFdy, round, reciprocal, trunc, fwidth, bitcast, atan2, min, max, mod, step, reflect, distance, difference, dot, cross, pow, pow2, pow3, pow4, transformDirection, mix, clamp, saturate, refract, smoothstep, faceForward } from './math/MathNode.js';
+export { default as MathNode, EPSILON, INFINITY, radians, degrees, exp, exp2, log, log2, sqrt, inverseSqrt, floor, ceil, normalize, fract, sin, cos, tan, asin, acos, atan, abs, sign, length, negate, oneMinus, dFdx, dFdy, round, reciprocal, trunc, fwidth, bitcast, atan2, min, max, mod, step, reflect, distance, difference, dot, cross, pow, pow2, pow3, pow4, transformDirection, mix, clamp, saturate, refract, smoothstep, faceForward, cbrt } from './math/MathNode.js';
 export { default as OperatorNode, add, sub, mul, div, remainder, equal, lessThan, greaterThan, lessThanEqual, greaterThanEqual, and, or, xor, bitAnd, bitOr, bitXor, shiftLeft, shiftRight } from './math/OperatorNode.js';
 export { default as CondNode, cond } from './math/CondNode.js';
 export { default as HashNode, hash } from './math/HashNode.js';

examples/jsm/nodes/math/MathNode.js

@@ -297,6 +297,7 @@ export const pow3 = nodeProxy( MathNode, MathNode.POW, 3 );
 export const pow4 = nodeProxy( MathNode, MathNode.POW, 4 );
 export const transformDirection = nodeProxy( MathNode, MathNode.TRANSFORM_DIRECTION );
 
+export const cbrt = ( a ) => mul( sign( a ), pow( abs( a ), 1.0 / 3.0 ) );
 export const mix = nodeProxy( MathNode, MathNode.MIX );
 export const clamp = ( value, low = 0, high = 1 ) => nodeObject( new MathNode( MathNode.CLAMP, nodeObject( value ), nodeObject( low ), nodeObject( high ) ) );
 export const saturate = ( value ) => clamp( value );
@@ -357,5 +358,6 @@ addNodeElement( 'smoothstep', smoothstepElement );
 addNodeElement( 'faceForward', faceForward );
 addNodeElement( 'difference', difference );
 addNodeElement( 'saturate', saturate );
+addNodeElement( 'cbrt', cbrt );
 
 addNodeClass( 'MathNode', MathNode );