return function ( particle ) { particle.age = 0; utils.asVector( zone, vector ); particle.lifeTime = utils.vectorLength( vector ); };
return function ( particle ) { particle.velocity = utils.asVector( zone ); particle.vectors.push( particle.velocity ); };
return function ( particle ) { particle.position = utils.asVector( zone ); particle.vectors.push( particle.position ); };