The infrastructure layer consists of a combination of topology graphs secured on a decentralised ledger. The topology graphs organise non-fungible digital tokens which each represent and correspond to building components, and in the root of the graph to the building itself.We present background research in the relationship of building representation in the form of graphs with topology, of both manifold and non manifold nature. In parallel we present and analyse the relationship between digital representation and physical manifestation of a building, and back again. Within the digital representations the paper analyses the securing and saving of information on decentralised ledger technologies (such as blockchain). We then present a simple sample of generating and registering a non-manifold topology graph on the Ethereum blockchain as an EC721 token, i.e. a digital object that is unique, all through the use of dynamo and python scripting connected with a smart contract on the Ethereum blockchain. Ownership of this token can then be transferred on the blockchain smart contracts. We concludes with a discussion of the possibilities that this integration brings in terms of material passports and a circular economy and smart contracts as an infrastructure for whole-lifecycle BIM and digitally encapsulates of value in architectural designPlease write your abstract here by clicking this paragraph.
Technologies used: Topologic.app / Web3.py scripts / Dynamo and Grasshopper and Blender / ERC721 contract written in Solidity, using the Open Zeppelin templates for ERC721:
Within our computational analysis, we use a series of encapsulated graphs to represent buildings, using the topology library topologic.app. Each node in the root graph corresponds to a space in an existing building or a building under design. The second layer of graphs stems the initial graph, and in a series of layers and connections of nodes to components of the building, represent in graph form the whole ontology of the building. Consequently a series of tokens that represent the nodes to the graph get created on a contract we control on the Ethereum Blockchain. While tokens that represent building components can be interchangeable, the tokens that represent unique nodes in the building, and the root of the graph, are non-fungible, and unique, i.e. not interchangeable.
Our prototype implementation involves executing a simple topologic definition in Dynamo that generates a cell complex of nine cubes, side-10, and then topologically analysing each of the cells into the faces and edges that comprise the cell.
We then upload the topology definition on the interplanetary filesystem, a decentralised file repository that is used in decentralised applications, since saving whole files on the blockchain is both difficult but also computationally expensive to the point that it becomes impractical. Files on IPFS are connected with a cryptographic hash generated by the SHA256 algorithm. This hash is a unique representation each file stored on the IPFS storage. By uploading the dynamo definition on IPFS it is assigned thus a unique hash, based on the nature of the file.We then upload the topology definition on the interplanetary filesystem, a decentralised file repository that is used in decentralised applications, since saving whole files on the blockchain is both difficult but also computationally expensive to the point that it becomes impractical. Files on IPFS are connected with a cryptographic hash generated by the SHA256 algorithm. This hash is a unique representation each file stored on the IPFS storage. On the Ethereum Ropsten Test network we have deployed a Token Minting contract. The tokens generated have beyond their unique number, the following variables: a hash in the form of a string, a price and an address that owns the token.