5 ms·

Does anyone use these generative city modeling compositions that align to a vector base map of actual cities? It would be fun to see these 3D cities as fiction

by mycall 3y ago

Does anyone use these generative city modeling compositions that align to a vector base map of actual cities? It would be fun to see these 3D cities as fictional versions of known locations. I could see city planners use it for "what-if" scenarios.

PaulHoule 3y ago
An awful lot of cities have a "digital twin" of some sort in the planning department and frequently the data is public. It would be pretty neat to be able to work from this material.
- dagw 3y ago
  An awful lot of cities have a "digital twin" I work in the field, and the truth is that an awful lot of cities _claim_ to have a digital twin. When what they actually have us a big pile of random GIS data and some 10 year old 3D models someone made once and never updated.
lukasgraf 3y ago
CityEngine [1] does that. It's a procedural city generation engine first presented at SIGGRAPH 2001, by Procedural Inc., an ETH Zürich spinoff that was later acquired by ESRI (ArcGIS). At its core is a shape grammar based on L-Systems [2] that is used to define how a road network is subvided into lots, then buildings etc.. with increasing level of detail and contextual constraints. You give it a vector road network and the grammar rules, and it subdivides it spacially into e.g. Lots > Buildings > Roofs > Stories > Facades > Windows > Frame > Glass pane > Ledge etc., according to the desired level of detail. Context dependent rules control that e.g. doors may only be placed on the ground floor, or the the roof goes on top of the top floor. The original paper and presentation at SIGGRAPH described the simplicity of the core idea quite beautifully, but I'm having a hard time finding them now. This old tech demo video [3] should give an idea of how it works though. [1] https://en.wikipedia.org/wiki/CityEngine https://en.wikipedia.org/wiki/CityEngine [2] https://en.wikipedia.org/wiki/L-system https://en.wikipedia.org/wiki/L-system [3] https://www.youtube.com/watch?v=SxyOTUzm2qw https://www.youtube.com/watch?v=SxyOTUzm2qw
- andybak 3y ago
  Sounds like an implementation of a Shape Grammar: https://en.wikipedia.org/wiki/Shape_grammar https://en.wikipedia.org/wiki/Shape_grammar with some geospatial hooks. Shape Grammars are interesting. Closely related to L-systems but usually with a more approachable syntax. Also see https://github.com/stefalie/shapeml https://github.com/stefalie/shapeml
lainga 3y ago
This is kind of weird tying-together comment, but Townscaper (referenced in btbuildem's comment []) was partly inspired by an (deterministic non-NN) application, which the creator was working on for someone else, that did just that. I can't find the tweet, but if you go back through @OskSta's history, he discusses it. [] https://news.ycombinator.com/item?id=37466936 https://news.ycombinator.com/item?id=37466936
- zimpenfish 3y ago
  He covers his work on "Night Call" which was generating Paris on-the-fly from about 8:15 to 13:30 in https://www.youtube.com/watch?v=5xrRTOikBBg https://www.youtube.com/watch?v=5xrRTOikBBg

by mycall 3y ago

PaulHoule 3y ago

An awful lot of cities have a "digital twin" of some sort in the planning department and frequently the data is public. It would be pretty neat to be able to work from this material.

dagw 3y ago
An awful lot of cities have a "digital twin" I work in the field, and the truth is that an awful lot of cities _claim_ to have a digital twin. When what they actually have us a big pile of random GIS data and some 10 year old 3D models someone made once and never updated.

lukasgraf 3y ago

CityEngine [1] does that. It's a procedural city generation engine first presented at SIGGRAPH 2001, by Procedural Inc., an ETH Zürich spinoff that was later acquired by ESRI (ArcGIS). At its core is a shape grammar based on L-Systems [2] that is used to define how a road network is subvided into lots, then buildings etc.. with increasing level of detail and contextual constraints. You give it a vector road network and the grammar rules, and it subdivides it spacially into e.g. Lots > Buildings > Roofs > Stories > Facades > Windows > Frame > Glass pane > Ledge etc., according to the desired level of detail. Context dependent rules control that e.g. doors may only be placed on the ground floor, or the the roof goes on top of the top floor. The original paper and presentation at SIGGRAPH described the simplicity of the core idea quite beautifully, but I'm having a hard time finding them now. This old tech demo video [3] should give an idea of how it works though. [1] https://en.wikipedia.org/wiki/CityEngine https://en.wikipedia.org/wiki/CityEngine [2] https://en.wikipedia.org/wiki/L-system https://en.wikipedia.org/wiki/L-system [3] https://www.youtube.com/watch?v=SxyOTUzm2qw https://www.youtube.com/watch?v=SxyOTUzm2qw

andybak 3y ago
Sounds like an implementation of a Shape Grammar: https://en.wikipedia.org/wiki/Shape_grammar https://en.wikipedia.org/wiki/Shape_grammar with some geospatial hooks. Shape Grammars are interesting. Closely related to L-systems but usually with a more approachable syntax. Also see https://github.com/stefalie/shapeml https://github.com/stefalie/shapeml

lainga 3y ago

This is kind of weird tying-together comment, but Townscaper (referenced in btbuildem's comment []) was partly inspired by an (deterministic non-NN) application, which the creator was working on for someone else, that did just that. I can't find the tweet, but if you go back through @OskSta's history, he discusses it. [] https://news.ycombinator.com/item?id=37466936 https://news.ycombinator.com/item?id=37466936

zimpenfish 3y ago
He covers his work on "Night Call" which was generating Paris on-the-fly from about 8:15 to 13:30 in https://www.youtube.com/watch?v=5xrRTOikBBg https://www.youtube.com/watch?v=5xrRTOikBBg