From SOFAWiki

Description

This engine finds the topological primitives which are inside a given sphere.

Note: SphereROI engine new design is a merge between old design of PrimitivesInSphereROI concerning only vertices and TrianglesInSphereROI. engine which was handling only triangles.
Topological primitives handle are now:

- dofs/vertices
- edges
- triangles
- tetrahedra

Input Data's

• centers

Center(s) of the sphere(s).

• radii

Radius(i) of the sphere(s).

• direction

Edge direction(if edgeAngle > 0).

• normal

Normal direction of the triangles (if triAngle > 0).

• edgeAngle

Max angle between the direction of the selected edges and the specified direction.

• triAngle

Max angle between the normal of the selected triangle and the specified normal direction.

• position/rest_position

Rest position coordinates of the degrees of freedom

Input topology (those input are not necessary for the :

• edges

Edge Topology array.

• triangles

Triangle Topology array.

• tetrahedra

Tetrahedron Topology array.

Input parameters

Concerning topology Note that those parameters are set to true by default. So it means that as default behaviour, all topological component array will be parse. Set some parameters to false if you just need a part of the information and want to speed-up your simulation.

• computeEdges

If true, will compute edge list and index list inside the ROI.

• computeTriangles

If true, will compute triangle list and index list inside the ROI.

• computeTetrahedra

If true, will compute tetrahedra list and index list inside the ROI.

For display:

• drawSphere

If true, Draw shpere(s).

• drawPoints

If true, Draw Points.

• drawEdges

If true, Draw Edges.

• drawTriangle

If true, Draw Triangles.

• drawTetrahedra

If true, Draw Tetrahedra.

• drawSize

rendering size for box and elements.

Output Data's

• indices

Indices of the points contained in the ROI.

• edgeIndices

Indices of the edges contained in the ROI.

• triangleIndices

Indices of the triangles contained in the ROI.

• tetrahedronIndices

Indices of the tetrahedra contained in the ROI.

• pointsInROI

Points contained in the ROI.

• edgesInROI

Edges contained in the ROI.

• trianglesInROI

Triangles contained in the ROI.

• tetrahedraInROI

Tetrahedra contained in the ROI.

Examples

Examples using this engine can be found in :

Sofa/examples/Components/engine/SphereROI.scn

Thus one use can be to define a SphereConstraint:
where the engine is used as follow:

<Node name="Group">
       <MechanicalObject name="Volume" />
       <SphereROI centers="0 0 0" radii="0.2" drawSphere="1"
                           position="@Volume.rest_position" computeTriangles="0"
                           computeTetrahedra="0" computeEdges="0" name="FixedROI"/>
       <FixedConstraint indices="@FixedROI.indices" />         
</Node>

Other use can be to find the topology:
where the engine is used as follow:

<Node name="Group">
    <MechanicalObject template="Vec3d" name="mecaObj"  scale3d="10 10 10"  restScale="1" />
    <TriangleSetTopologyContainer name="Container" />
    <SphereROI centers="0 0 1" radii="0.2" drawSphere="1"
                           position="@../Volume.position" drawTriangles="1" drawTetrahedra="1"
                           triangles="@Container.triangles" tetrahedra="@../Container.tetrahedra" name="boxROI"/>
</Node>