An Overview of SOFA (Simulation Open

Framework Architecture)

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Shamyl Bin Mansoor and Mohsin Nasir

SMART Lab, SEECS, NUST

Outline• What is SOFA• Modeling in SOFA• Multimodal Representation• Simulation in SOFA• Features of SOFA• Using SOFA

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What is SOFA ?

• An open source framework for surgical simulators• Developed by 3 INRIA (France) Teams helped by

CIMIT Sim Group (US), ETH Zurich and CSIRO (Australia)

• Currently under development with SOFA Version 1 beta 4 released in 2009

• Currently most research in medical simulation is being done using SOFA Framework

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What is SOFA ?

• Simulation Open Framework Architecture (SOFA) is– An open source C++ library for

physical simulation primarily targeted to medical simulation

– It can be used as an external library or in another program or using one of the associated GUI applications

– Highly flexible– Allows the use of multiple

interacting geometrical models of the same object CC

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Features of SOFA

• Force fields• Mappings• Constraints• Articulated Bodies• Fluids• GUI• Haptics

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Modeling in SOFA

• Mechanical Model• Collision Model• Visual Model– Each model can be designed

independently– During run-time, consistency is

maintained using mappings

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SOFA Liver Example

Simulation in SOFA• SOFA scenes are modeled using

hierarchical scene graphs• This allows splitting of physical objects

into collections of independent components

• Components can be replaced by other components e.g Spring forces replaced by FEM forces

• Simulation algorithms like time integration or collision detection and modeling are modeled as scene graph components

• Same flexibility for algorithms as for models

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Simulations in SOFA

• Scene graph traversals for calculation of forces at each component

• These forces are accumulated and then solved using Ordinary Differential Equation Solvers (ODEs).

• There are several ODE solvers available in SOFA

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The whole process

Model

Create Simulation Scene

Animate (Run Simulation)

Using SOFA for modeling

• SOFA can be downloaded from – www.sofa-framework.org

• Currently there are 3 ways of modeling simulation scenes– Using SOFA Modeler– Using XML– Using C++

• Simulations can be run using the runSOFA application or using C++ CC

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Using SOFA

SOFA Component

s

Drag & Drop

Run Simulation

Scene

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Animate Scene

Thank You

Lets move on to the Hands On Exercises