Why Art Blocks Uses JavaScript in Its Smart Contract

Why is the image not generated/rendered on-chain? It’s because the scripts have library dependencies. The scripts depend on common JavaScript libraries such as  p5.js  and  processing  which are commonly used by designers to create generative images. It would be very expensive to put these dependency libraries on-chain and that’

So, what do you really own when you buy an NFT? In this case, you just own the  tokenId .  tokenUri  function then maps the  tokenId  to either IPFS or HTTP link depending on the project settings. This link either points to the image directly or to a JSON that has attributes and a nested link to the image.

But how is the image generated/rendered? Unfortunately, the image is not generated on-chain. The smart contract only stores a JavaScript script needed to render the image. Art Blocks’ frontend then queries this script and generates the image on-demand in its traditional backend, not the blockchain backend.