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Description

In this tutorial, a deformable cube undergoes internal and external forces. This is one of the simplest scenes we can simulate using Sofa. We use it to introduce the component structure.

The shape is modeled using a MechanicalObject which desribes the particle states, and a Topology which describes how the particles are connected.

The forces are the MeshSpringForceField, which defines springs according to the edges of the mesh (the Topology), and the PlaneForceField which try to prevent the particles to cross planes.

The EulerImplicitSolver contains the algorithm used to update particle positions and velocities at each time step. It uses an auxiliary component, the CGLinearSolver, to solve equation systems.

Try this

examples/Tutorials/Basic/TutorialBasicCube.scn

Open the scene file in a text editor, modify parameters, save and re-open the scene in SOFA. Alternatively, you can edit the scene using the Sofa modeler program.

Prerequisite

• Working installation of SOFA. See http://www.sofa-framework.org/installation

Example Scene

examples/Tutorials/Basic/TutorialBasicCube.scn

Graph

XML Description

<?xml version="1.0" ?>
<!-- See http://wiki.sofa-framework.org/mediawiki/index.php/TutorialBasicCube -->
<Node name="root" dt="0.01" gravity="0 0 -9.81" showBehavior="1">
 
  <EulerImplicitSolver name="EulerImplicit" />
  <CGLinearSolver name="CG Solver" />
 
  <MechanicalObject name="Particles" template="Vec3"
                    position="0 0 1  1 0 1  0 1 1  1 1 1  0 0 2  1 0 2  0 1 2  1 1 2" />
  <MeshTopology name="Topology" hexas="0 4 6 2 1 5 7 3" />
 
  <UniformMass name="Mass" totalmass="1" />
  <MeshSpringForceField name="Springs" stiffness="100" damping="1" />
 
  <PlaneForceField name="Floor" normal="0 0.2 1" stiffness="100" damping="1" draw="1" />
  <PlaneForceField name="Wall" normal="0 -1 0" d="-4" stiffness="100" damping="1" draw="1" color="1 1 1" />
 
</Node>