WP4: Efficient visualisation and streaming Tasks

 Efficient visualization and streaming ◦ Problem: huge datasets  Guarantee interactive framerates  Data transfer from servers  Status ◦ Interactive City Viewer demo  Both on desktop and Mobile (iPhone) systems  Streaming data from server  Using TeleAtlas 3D city data  Horizon Culling

 Quadtree ◦ Splitting rule: number of buildings ◦ Leaf cells store building data  Geometry  Collision geometry  Segments for horizon culling (building tops)  Each cell can be requested separately

 Paris ◦ Geometry: 1.4 GB ◦ Collision geometry: 89 MB ◦ Texture Atlas: 5 texture atlas files (2048x2048)  106 MB (.dds format with mipmap levels) ◦ Segments: 40 MB  Barcelona ◦ Geometry: 600 MB ◦ Collision geometry: 31 MB ◦ Texture Atlas: 4 texture atlas files (2048x2048)  87 MB (.dds format with mipmap levels) ◦ Segments: 14 MB

 “A Flexible and Extensible Architecture for Visibility Culling”  Miquel À. Rújula, Jeroen Dierckx, Tom Jehaes, Peter Quax, Wim Lamotte and Pere A. Palmer  Conference on Computer Game Design and Technology

 Further experimentation with different splitting strategies for building the quadtree ◦ Important factors: render performance, download size per cell, segment count, …  Experiment with different strategies for building the texture atlas ◦ One for the whole city one for each cell  Build on previous experience with LoD solutions ◦ Combinations of traditional 3D models with image-based and procedurally generated models  Leverage the existing quadtree data model for LoD ◦ Parent nodes store a lower resolution version of the merged children  Procedurally generated data?

 Interaction framework ◦ Flexible interaction specification  Status ◦ Scripting completely integrated into the existing framework ◦ Application interaction is defined by writing scripts ◦ Visual world editor preliminary version

-- Key bindings function onKeyPressed(event) if event.key == Keyboard.KC_1 then billboard1.URL = “controls.swf" elseif event.key == Keyboard.KC_2 then billboard1.URL = " elseif event.key == Keyboard.KC_3 then billboard1.URL = " elseif event.key == Keyboard.KC_3 then billboard1.URL = " end listener = InputManager:createKeyboardListener() listener.keyPressed = onKeyPressed -- Create the demo billboard settings = BillboardSettings() settings.sceneMgr = Application:getCamera().sceneManager settings.mesh = "../../data/Ogre/meshes/billboards/wall-billboard.mesh" settings.subMesh = 2 settings.zoomTime = 0.5 settings.width = 800 settings.height = 600 settings.startURL = “controls.swf" settings.position = OgreVector3(-48, 2, -61) billboard1 = BillboardManager:createBillboard(1, settings)

 Integration into a webbrowser ◦ ActiveX, Firefox plugin, …  WorldEditor ◦ Flexible interaction specification  Flow diagrams?  Services: synchronize with SMIT  Service examples ◦ Targeted advertising  Based on user profile, previous interests, … ◦ Accounting  Number of viewers, number of clicks, …