Parametric-based Reconstruction Of 3D Mesh Models; Towards the Generation of a Parametric Human Foot Biomodel

In this work a new reconstruction technique is presented based on Parametric-Based Deformation. The new method uses a template 3D mesh model which is deformed according to user-defined semantic parameters in order to derive a new 3D object. The proposed methodology is divided in three stages: template construction (production of a template mesh model), regression (the template model is deformed to match sample models) and prediction (new instance mesh models are derived based on user parameters). The proposed method has been successfully applied for the reconstruction of human and animal skeletal models. A practical and novel reconstruction methodology has been developed and implemented for the reconstruction of the human foot given a bi-planar X-ray. The purpose of this methodology is to support the parametric generation of human foot biomodels in an automated way. The generated biomodels are employed by simulation tools based on Finite Element Analysis to test the stress factors that the foot is undertaking during its contact with the ground or a footwear sole structure. 1. The basic parameterization methodology The automatic generation of a 3D model which belongs in a specific category like a human body, face or bone, with specific semantic parameters is an important topic in CAD/Computer Graphics. There is a plethora of applications involved in this process, like for example crowd simulation, animation and garment design based on specific body-type and height. Concerning bones, this process is crucial because it reduces the time a bone is reconstructed which is vital for in-vivo situations like quick diagnosis from the doctor and fast/accurate surgery preparation. Also by this way the patient is not exposed to hazardous CT scan radiation, while the need for undergoing the tedious process of MRI scan is minimized. Parametric bone reconstruction is also important in applications which employ bio mechanical analysis with the use of Finite Element Method (FEM). This work describes and illustrates the last application mentioned above. The methodology used follows the concept introduced in [LJ14] where a given prototype 3D mesh P is deformed to a new 3D mesh M according to given parameters (p1 , p M 2 , . . . , p M k ). The whole procedure is based on three stages, illustrated also in Figure 1. First mesh simplification which preserves topology is applied to P acquiring mesh Pc which is called as control mesh. In the first stage, a mapping between the prototype mesh P with Figure 1: The basic stages of the proposed methodology: (1) Generation of Pc and establishment of relationship between P and Pc. (2) Modification of the control mesh Pc to Pc using the input parameters. (3) Generation of the new deformed shape M the control mesh Pc is established. At the second stage, the control mesh Pc is modified using a linear transformation with parameters (p1 , p M 2 , . . . , p M k ) deriving the control mesh Pc. At the third stage, the modified control mesh Pc is used to deform mesh P into M. c © The Eurographics Association 2015. A. Agathos & P. Azariadis / Parametric-based reconstruction of 3D mesh models