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Volume 21 Issue 08 - Publication Date: 1 August 2002
 
Acquisition of Elastic Models for Interactive Simulation
 
Jochen Lang, Dinesh K. Pai and Robert J. Woodham Department of Computer Science University of British Columbia Vancouver, Canada
 
We present method and implementation to acquire deformable models of elastic objects. The method is based on the Green's functions matrix representation of an elastic solid. In this paper, we present a robust estimation technique for this Green's functions matrix. Robustness is achieved by regularization and a fitting technique which we describe here in detail. The underlying data for estimation are acquired with a robotic measurement system. We describe the UBC Active Measurement System (ACME) as it relates to the deformable model acquisition. In particular, we characterize the ability of ACME to record the global deformation of an object based on our previously presented range-flow technique. We provide results for two elastic objects: a plush toy and a medical physical soft-tissue wrist model.
 
Multimedia Key
= Video = Data = Code = Image
       
 
 
Extension
Type
Description
1
Haptic and visual interaction with an acquired deformable model. The video clip shows the probing of a plush toy at some locations in ACME. ACME is the UBC Active Measurement Facility. Following the probing, haptic interaction with the deformable model is shown. The deformable modeling is based on observations with a trinocular stereo-head. The tinocular imagery is employed to calculate the surface range flow during an robotic deformation of the plush toy.
2
Animation of the estimated local normal compliance for the plush toy. The compliance is the 3 dimensional block-diagonal of the discrete Green's function matrix (see Section 7 of the paper). The simulation shows the compliance in the direction normal to the surface.
3
Discrete Green's function for vertex 55 on the head of the plush toy. The x, y and z column of the discrete Green's function are rendered separetely in the x-direction, the y-direction and the z-direction. The animated displacements are simulated with the Green's function response due to tractions acting along the corresponding axis of the object coordinate system.
4
Discrete Green's function for vertex 38 on the back of the plush toy. The x, y and z column of the discrete Green's function are rendered separetely in the x-direction, the y-direction and the z-direction. The animated displacements are simulated with the Green's function response due to tractions acting along the corresponding axis of the object coordinate system.
5
Animation of the estimated local normal compliance for the medical soft-tissue wrist model. The compliance is the 3 dimensional block-diagonal of the discrete Green's function matrix (see Section 7 of the paper). The simulation shows the compliance in the direction normal to the surface.
6
Discrete Green's function for vertex 4 on the hand of the soft-tissue wrist model. The x, y and z column of the discrete Green's function are rendered separetely in the x-direction, the y-direction and the z-direction. The animated displacements are simulated with the Green's function response due to tractions acting along the corresponding axis of the object coordinate system. The Green's function models the global deformation due to the bending of the complete object.
7
Discrete Green's function for vertex 98 close to the mount of the soft-tissue wrist model. The x, y and z column of the discrete Green's function are rendered separetely in the x-direction, the y-direction and the z-direction. The animated displacements are simulated with the Green's function response due to tractions acting along the corresponding axis of the object coordinate system. The Green's function models the purely local deformation at this location due to the compression of the "soft-tissue" foam between the probe and the "bone" of the object.
 
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