Replace artist permalink to single artwork

functions.php

<?php

function bhasia_artist_permalink($url, $post) {

	if(get_post_type($post->ID) == 'artist') {
		$ids = get_post_meta($post_id, '_artworks');
		if($ids) {
			$url = get_permalink(array_shift($ids));
		}	
	}

	return $url;

}
add_filter('post_type_link', 'bhasia_artist_permalink');

?>