Master Thesis Presentation Large Shared Haptic Virtual Environments Nakul Chaudhari nakul.chaudhari@tum.de Supervisors: Clemens Schuwerk clemens.schuwerk@tum.de Marc-Oliver Pahl pahl@net.in.tum.de Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Agenda Introduction □ haptic device and a computer haptic application □ motivation What is a networked haptic application? □ traditional architectures for collaborative haptic applications Scaling haptic virtual environments Area of interest □ static partitioning □ dynamic partitioning Results Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Simple haptic device with 3 degrees of freedom point, HIP actor using the resting device movement along various DOF - video HIP - haptic interface pointer position Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Simple haptic device with 3 degrees of freedom point, HIP actor using the resting device movement along various DOF - video HIP - haptic interface pointer position Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München 1 2 4 surface effects - 1-smooth 3 2-water 3-rough 4-magnetic Computer haptics - graphical rendering video 4 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München 1 2 4 surface effects - 1-smooth 3 2-water 3-rough 4-magnetic Computer haptics - graphical rendering video 4 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München 1 2 4 surface effects - 1-smooth 3 2-water 3-rough 4-magnetic Computer haptics - graphical rendering video 4 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Motivation scale world and collaborating users maintain consistency, transparency, and realistic feedback only one task no change in camera state one single and big VE collaborate on different tasks translate camera, zoom in / out Previous work in haptics generally surrounded spatially small worlds This thesis: different users collaborating with other users on different tasks Needs: architecture which supports such scaling 5 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Abbreviations HIP - haptic interface pointer □ position of the haptic device (or the user) VE - virtual environment or virtual world P2P - peer to peer RTT - round trip time in network communication AOI - area of interest □ area surrounding a user in the VE, e.g. volume covered by a sphere drawn around the user 6 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Networked haptic applications & Traditional architectures 7 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Networked haptic applications Local Local Visual Control Control Display Loop Network Loop Teleoperator Operator p Sensors Haptic and Display Actuators Example scenario - teleoperation adopted from Steinbach et al., Haptic data compression and communication. IEEE Signal Processing Magazine 8 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Networked haptic applications Local Local Visual Control Control Display Loop Network Loop Teleoperator Operator p Sensors Haptic and Display Actuators Example scenario - teleoperation adopted from Steinbach et al., Haptic data compression and communication. IEEE Signal Processing Magazine 8 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Networked haptic applications Network Device position Loop 1kHz *P .D. Force, Audio, Video Challenges Separate □ high header to payload ratio thread at 30 Hz □ high update rate of 1kHz *P .D. Perceptual deadband scheme for packet reduction □ stability issues due to network delay 9 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Computer haptics Visual Rendering Visual Feedback (30-100 Hz) Position Sensing Virtual Object Network / Database Storage Collision Detection !"# !$# Response Force Computation Force Torque Physics Engine Human-System Communication Haptic Feedback (1000 Hz) Interface 10 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Networked haptic applications & Traditional architectures for collaboration 11 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Collaboration between networked Haptic Applications collaboration - video 12 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Collaboration between networked Haptic Applications collaboration - video 12 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Simple client server !"#$"# Physics Graphics Force 0.&1,1.2'.#'$"3.41,5'.6'789 Issues Engine Engine Rendering :;0,14&<'$1=".<';>=1. □ control loop □ RTT time required □ not scalable +",-.#/ Features □ consistency □ less resources at client needed %&"#'* %&"#'( %&"#') 13 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Consistency client server (CoS) !"#$%&'#()*+',-', Improvement Physics 2"%$&$"#*",*-':"($&)*"3*;<= Engine -$,&>?:*"@A'(&*>2B?&'% □ local force rendering, hence stable Issues 8'&0",9 □ RTT time required □ not scalable Features □ consistency .%',*7 .%',*/ 0$&1*("2)*"3*45 0$&1*("2)*"3*45 Graphics Force .%',*6 Engine Rendering 0$&1*("2)*"3*45 14 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Peer to peer (P2P) !"#$%2 '()*%+,-.%,/%01 Improvement 6(7($#+)(,89:%*9-)(+% +,;;<8(+9)(,8%6#)'##8%<"#$" □ no RTT required □ more scalable then previous approaches Issues 4#)',$5 □ inconsistent virtual world: as every user is using his current HIP and other users HIP state which is ‘delay’ time old !"#$%3 !"#$%& '()*%+,-.%,/%01 '()*%+,-.%,/%01 Graphics Physics Force Engine Engine Rendering 15 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Inconsistency user 1 user 2 Naive p2p implementation 16 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Scaling virtual world 17 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Scaling virtual environment 1ms 1ms - max limit on 640 iteration time due to 1kHz update rate Number of objects 160 40 ConvertToGlobal 30 20 detectCollision 10 0 2 4 6 8 10 12 14 updateVEState Time required in ms per module Virtual world containing simple cubes Modules of update haptics routine □ which are computed at the rate of 1kHz □ whose computation time required increases linearly with number of objects 18 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Area of Interest 19 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Area of interest (AOI) of a user A Users B Virtual objects AOI of a user Top view of a VE 20 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Rendering area of interest (AOI) of a user user/ HIP grid of user cubes moving slightly to the right 21 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Static partitioning Figure 7.2: 1.5 A A B B fully meshed P2P, considering user A AOI of user A and B 22 Wednesday, April 3, 2013
Institute for Media Technology Prof. Dr.-Ing. Eckehard Steinbach Technische Universität München Static partitioning A A B B A and B’s AOI intersect, distant inconsistency - add a server, exchange HIP only between intersecting users who can be queried for latest VE state 23 Wednesday, April 3, 2013
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