Already put. Can somebody explain to me... for example, I want to buy a 3d model of a train - it shows me a licence like Royalty Free License Royalty Free License allows you to use the product without the need to pay royalties or other license fees for multiple uses, per volume sold, or some time period of use or sales. Products published with this license may not be sold, given, or assigned to another person or entity in the form it is downloaded from the site, but can be used in your commercial projects multiple times after paying for it just once. So if i understand correctly i can modify it use in my videos and can upload here but in another format that differs from original file. Is i am correct or I'm wrong, please explain. Sorry for stupid question. But i want to make normal trains so suddenly nobody appeared from nowhere.