Do you have a screenshot of the issue, not sure what your refering too. Haven't noticed any issue between Truesky and Ceto besides ocean being cut off when camera at heigth which can be fixed by changing border from default value of 500 to a large values 10000. Edit: what version of simul are you running? Previous versions is Truesky did not add transparent objects to its mask. So unless for had terrain all the way to horizon ocean would be cut off. Had same issue with sumino and Truesky, Roderick fixed this in latest version which I got direct from him. Think the asset store version is updated now to latest.