ERC-4883: Composable SVG NFT


  Ethereum Improvement Proposals
        
        
          
            
              
            
          
        

        AllCoreNetworkingInterfaceERCMetaInformational

      



      
        
  
    

  
    
    
    
      ⚠️ Draft
    
    
    
      Standards Track: ERC
    
  
  
    
      ERC-4883: Composable SVG NFT
    
    
      
        
      
    
    
      
        
      
    
  

  Compose an SVG NFT by concatenating the SVG with the rendered SVG of another NFT.

  	Authors	Andrew B Coathup (@abcoathup), Alex (@AlexPartyPanda), Damian Martinelli (@damianmarti), blockdev (@0xbok), Austin Griffith (@austintgriffith)
	Created	2022-03-08
	Discussion Link	https://ethereum-magicians.org/t/eip-4883-composable-svg-nft/8765
	Requires	

  EIP-165, 

  EIP-721




  


  

  
    Table of Contents

    	Abstract
	Motivation
	Specification
	Rationale
    	Ordering of concatenation
	Alternatives to concatenation
	Sizing
	Render function name


  
	Backwards Compatibility
	Security Considerations
	Copyright



  


  
      
      
         Abstract
      
      
    


Compose an SVG (Scalable Vector Graphics) NFT by concatenating the SVG with the SVG of another NFT rendered as a string for a specific token ID.

  
    
      
      
         Motivation
      
      
    


Onchain SVG NFTs allow for NFTs to be entirely onchain by returning artwork as SVG in a data URI of the tokenUri function. Composability allows onchain SVG NFTs to be crafted. e.g. adding glasses & hat NFTs to a profile pic NFT or a fish NFT to a fish tank NFT.

  
    
      
      
         Specification
      
      
    

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.


/// @title EIP-4883 Non-Fungible Token Standard
interface IERC4883 is IERC165 {
    function renderTokenById(uint256 id) external view returns (string memory);
}





renderTokenById must return the SVG body for the specified token id and must either be an empty string or valid SVG element(s).

  
    
      
      
         Rationale
      
      
    


SVG elements can be string concatenated to compose an SVG.

  
    
      
      
         Ordering of concatenation
      
      
    


SVG uses a “painters model” of rendering.


Scalable Vector Graphics (SVG) 1.1 (Second Edition), section: 3.3 Rendering Order


  Elements in an SVG document fragment have an implicit drawing order, with the first elements in the SVG document fragment getting “painted” first. Subsequent elements are painted on top of previously painted elements.




The ordering of the SVG concatenation determines the drawing order rather than any concept of a z-index.


This EIP only specifies the rendering of the rendered SVG NFT and does not require any specific ordering when composing.  This allows the SVG NFT to use a rendered SVG NFT as a foreground or a background as required.

  
    
      
      
         Alternatives to concatenation
      
      
    


SVG specifies a link tag.  Linking could allow for complex SVGs to be composed but would require creating a URI format and then getting ecosystem adoption.  As string concatenation of SVG’s is already supported, the simpler approach of concatenation is used.

  
    
      
      
         Sizing
      
      
    


This EIP doesn’t specify any requirements on the size of the rendered SVG.  Any scaling based on sizing can be performed by the SVG NFT as required.

  
    
      
      
         Render function name
      
      
    


The render function is named renderTokenById as this function name was first used by Loogies and allows existing deployed NFTs to be compatible with this EIP.

  
    
      
      
         Backwards Compatibility
      
      
    

This EIP has no backwards compatibility concerns

  
    
      
      
         Security Considerations
      
      
    


	SVG uses a “painters model” of rendering. A rendered SVG body could be added and completely obscure the existing SVG NFT artwork.
	SVG is XML and can contain malicious content, and while it won’t impact the contract, it could impact the use of the SVG.


  
    
      
      
         Copyright
      
      
    

Copyright and related rights waived via CC0.


  Citation

  Please cite this document as:

  
  Andrew B Coathup (@abcoathup), Alex (@AlexPartyPanda), Damian Martinelli (@damianmarti), blockdev (@0xbok), Austin Griffith (@austintgriffith), "ERC-4883: Composable SVG NFT [DRAFT]," Ethereum Improvement Proposals, no. 4883, March 2022. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-4883.






      
    
  

  

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