Hello everyone! My name is Tom!
Today i will start to tell you about NFT
Let’s start
Basically, all NFTs are divided into two types, on-chain and off-chain, but what is their difference?
What is off-chain
In short, off-chain = storing data outside the blockchain (which is logical by name). But here comes the moment of what we have always been told, they say your NFT is a blockchain! Did they deceive us? Let’s figure it out
To understand what kind of picture we have in front of our eyes, we need to perform a few simple steps (I will explain using the example of MAYC)
- We need to find the contract of the collection and go to the “contract” section CLICK
- Go to the “read contract” section CLICK
- Find the “tokenURI” field there and enter the number of the nft, whose data you are interested in, and click on “query”. At the output we will get this:
- Now we copy this link and paste it into the search bar, it should look something like this:
- Oh, and here is the metadata! Each field stores data that corresponds to this nft, that is, in the “image” field we have a link to the image, in “attributes” we have attributes, and so on. We are especially interested in the link in the “image” field. Copy it and paste it into the search bar again
Wow, and here is a picture of our MAYC! Ready!
And here we begin to feel a catch, because it turns out that we don’t have the picture itself, but just a link to the picture, which is stored in a completely different place, and if you change the picture using this link, the nft itself will change!
In fact, yes, but no, because often all pictures for nft are stored on decentralized data storages, which IPFS is
And now let’s talk about my favorite on-chain nft)
What is on-chain
on-chain = storing data in the blockchain (which is also logical). It turns out that these are the real NFTs that we deserve? In fact, yes, but so far we don’t need them, right now I’ll also tell you everything
To begin with, we need to repeat approximately the same circle as with off-chain nft (the analysis will be based on the example of my collection CLICK)
- We need to find the contract of the collection and go to the “contract” section CLICK
- Go to the “read contract” section CLICK
- Find the “tokenURI” field there and enter the number of the nft, whose data you are interested in, and click on “query”. At the output we will get this:
everything did not fit into the screen
- Now we copy all this text and paste it into the search bar, it should look something like this:
- So, metadata again! Again, we take the entire string from the “image” field, paste it into the search string and get this:
Wow, ready and working picture! No links! At least a miracle of the universe)
Conclusions:
So, well, it seems that during the article everyone understood everything, namely that on-chain = “cool”, and off-chain = “not cool”, but why doesn’t everyone do on-chain nft?
- This is expensive (in gas) both for the contract creator (contract creation transaction) and for the user (nft mint transaction), because we change more data in the transaction (there are fewer characters in the link than in that line from on-chain nft in the example)
- Less room for imagination. I will say this, drawing a picture and uploading it to a decentralized storage is easier than coding this picture, I generally keep quiet about traits and the rest
- It is impossible to make very large and high-quality nft. The contract has a memory limit (you can’t just upload 1000000 lines of code and believe that it will work, network will not let you through by the size of the contract)
I hope the article was interesting and understandable!
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Thank you! ❤️
