Stateless generation
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Stateless generation of distributed virtual worlds JIŘÍ DANIHELKA, LUKÁŠ KENCL, JIŘÍ ŽÁRA
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Transcript of Stateless generation
Stateless generation of distributed virtual worlds
JIŘÍ DANIHELKA, LUKÁŠ KENCL, JIŘÍ ŽÁRA
Stateless Generation of Distributed Virtual Worlds
Motivation Complex 3D virtual world shared on multiple
mobile devices
– the devices cannot store the whole world (the world can be potentially infinite)
– the world is generated on-demand based on view frustum
– we used infinite virtual cities as our main use case
– the mobile devices has to show the same geometry
– the devices has to work even when disconnected
Stateless Generation of Distributed Virtual Worlds
Paper idea How the problem can be solved
– mobile devices will share the same pseudo-random generator(share the same seed)
– each device will generate the content of its view frustum
– the content is consistent does not depend on previously generated geometry or states of other clients
– can work even offline
– we call our method “Stateless generation”
Stateless Generation of Distributed Virtual Worlds
Final result
Stateless Generation of Distributed Virtual Worlds
CityEngine CGA grammars
Stateless Generation of Distributed Virtual Worlds
Building modeling
Stateless Generation of Distributed Virtual Worlds
Transforming building to CGA grammer
Stateless Generation of Distributed Virtual Worlds
City generation pipeline
Stateless Generation of Distributed Virtual Worlds
Cars 2
Stateless Generation of Distributed Virtual Worlds
Related work Aliaga, Vanegas, Beneš:
Interactive Example-Based Urban Layout Synthesis
Stateless Generation of Distributed Virtual Worlds
Related work Aliaga, Vanegas, Beneš:
Interactive Example-Based Urban Layout Synthesis
Stateless Generation of Distributed Virtual Worlds
Related work Greuter S., Parker J., Stewart N., Leach G.
Real-time procedural generation of pseudo-infinite cities
Stateless Generation of Distributed Virtual Worlds
Our approach Delaunay triangulation
But can we do this on an infinite grid?
Stateless Generation of Distributed Virtual Worlds
Our approach Delaunay triangulation - proof
Stateless Generation of Distributed Virtual Worlds
Street segment interfaces Generated consistently using a hash function Cannot be overlapping
Stateless Generation of Distributed Virtual Worlds
Stateless generation Creating street nodes
(inspired by ray-tracing sampling)
Stateless Generation of Distributed Virtual Worlds
Stateless generation Creating possible street segments
Stateless Generation of Distributed Virtual Worlds
Stateless generation Minimum weight path
Angles can be transformed to edges using the graph’s dual form called “line graph”
Stateless Generation of Distributed Virtual Worlds
Stateless generation Lot generation
Stateless Generation of Distributed Virtual Worlds
Stateless generation Variations of street layout
Stateless Generation of Distributed Virtual Worlds
Measurements Stateless approach is not too demanding
Stateless Generation of Distributed Virtual Worlds
Measurements Rendering speed on a mobile phone (Lumia 920)
Stateless Generation of Distributed Virtual Worlds
Examples Big city
Stateless Generation of Distributed Virtual Worlds
Examples Antic Greece town
Stateless Generation of Distributed Virtual Worlds
Examples City suburbs
Stateless Generation of Distributed Virtual Worlds
Conclusions Advantages
– infinite worlds generated on-demand– consistent geometry in case of multiple clients– cities look more natural compared to previous work– can be used for scalable tasks (in cloud)
Drawbacks:– only for static content– path adding algorithm is greedy– currently only one level of streets
Thank you for attentionJiří Danihelka
Stateless Generation of Distributed Virtual Worlds
