static getNormal( a, b, c, target ) {

		target.subVectors( c, b );
		_v0$1.subVectors( a, b );
		target.cross( _v0$1 );

		const targetLengthSq = target.lengthSq();
		if ( targetLengthSq > 0 ) {

			return target.multiplyScalar( 1 / Math.sqrt( targetLengthSq ) );

		}

		return target.set( 0, 0, 0 );

	}
Computes the normal vector of a triangle.

@param {Vector3} a - The first corner of the triangle.
@param {Vector3} b - The second corner of the triangle.
@param {Vector3} c - The third corner of the triangle.
@param {Vector3} target - The target vector that is used to store the method's result.
@return {Vector3} The triangle's normal.