PointLocatorData Class Reference
PointLocatorData Class Reference

#include <xsi_pointlocatordata.h>

Class Description

A PointLocatorData object represents a collection of point locators. A point locator is a geometric surface coordinate, and represents a precise location on a geometry.

Point locators are topologically defined, so they are not dependent on the position or the deformation of the geometry (they "stick" to the surface). The actual data defining a point locator is abstracted and depends on the geometry type.

Point locators are a generalization of Point. As points, point locators can be processed independently from the geometry type. Like point indices, point locators are not related to a particular geometry instance. You can query any geometry having the same topology with the same PointLocatorData. For instance, you can use point locators to evaluate positions of an animated geometry at different times.

Because point locators don't apply to a particular geometry instance, the PointLocatorData object has no functionality by itself. Most methods related to PointLocatorData are defined in Geometry, PolygonMesh and NurbsSurfaceMesh. PointLocatorData can be created by the following methods:

Point locators are currently only supported by NurbsSurfaceMesh and PolygonMesh objects.

Other examples of PointLocatorData usage can be found in various related methods such as PointLocatorData::Count and PolygonMesh::ConstructPointLocators. A JScript example of a scripted operator can be found at PointLocatorData .

See also:
Geometry, Geometry::GetClosestLocations, Geometry::GetClosestLocationsWithinRadius, Geometry::SetupPointLocatorQueries, Geometry::GetSurfacePointLocatorsFromPoints, Geometry::GetRaycastIntersections, Geometry::EvaluatePositions, Geometry::EvaluateNormals, Geometry::EvaluateClusterProperty, PolygonMesh::GetPolygonIndexArray, PolygonMesh::GetTriangleVertexIndexArray, PolygonMesh::GetTriangleNodeIndexArray, PolygonMesh::GetTriangleWeightArray, PolygonMesh::ConstructPointLocators, NurbsSurfaceMesh::GetSubSurfaceIndexArray, NurbsSurfaceMesh::GetNormalizedUVArray, NurbsSurfaceMesh::ConstructPointLocators
This example uses PointLocatorData to deform a polygon mesh based on the closest weight map value of a NURBS surface mesh.
                using namespace XSI;

                // Scene creation:
                //   Polygon mesh grid and a NURBS surface grid.
                //   On the NURBS grid, a weight map having a radial gradient

                Application app;
                Model root = app.GetActiveSceneRoot();
                X3DObject meshGridObj;
                root.AddGeometry( L"Grid", L"MeshSurface", L"", meshGridObj );

                meshGridObj.PutParameterValue(L"subdivu", 24l);
                meshGridObj.PutParameterValue(L"subdivv", 24l);

                // We must freeze it, otherwise setting its position array will be forbidden:
                CValueArray args(3);
                CValue outArg;
                args[0] = meshGridObj.GetRef();
                app.ExecuteCommand(L"FreezeObj",args, outArg);

                Geometry meshGridGeom( meshGridObj.GetActivePrimitive().GetGeometry() );

                X3DObject NURBSGridObj;
                root.AddGeometry( L"Grid", L"NurbsSurface", L"", NURBSGridObj );
                NURBSGridObj.PutParameterValue(L"subdivu", 2l);
                NURBSGridObj.PutParameterValue(L"subdivv", 2l);

                NurbsSurfaceMesh NURBSGridGeom( NURBSGridObj.GetActivePrimitive().GetGeometry() );

                args[0] = CValue( CString(L"WeightMap") );
                args[1] = CValue( NURBSGridObj.GetRef() );
                args[2] = CValue(CString(L"MyWeightMap"));
                args[3] = CValue(CString(L"Weight Map Property"));
                app.ExecuteCommand( L"CreateWeightMap", args, outArg );
                ClusterProperty NURBSWeightMap(Cluster(NURBSGridGeom.GetClusters()[0]).GetProperties()[0]);

                args[0] = CValue(NURBSWeightMap.GetFullName() + L".weightmapop.type");
                args[1] = 5l ;
                app.ExecuteCommand( L"SetValue", args, outArg ) ;
                args[0] = CValue(NURBSWeightMap.GetFullName() + L".weightmapop.weight");
                args[1] = 1l ;
                app.ExecuteCommand( L"SetValue", args, outArg ) ;
                args[0] = CValue(NURBSWeightMap.GetFullName() + L".weightmapop.invert");
                args[1] = true ;
                app.ExecuteCommand( L"SetValue", args, outArg ) ;

                // Get the weight map again to have an updated copy
                ClusterProperty NURBSWeightMap2(Cluster(NURBSGridGeom.GetClusters()[0]).GetProperties()[0]);

                // Apply the deformation
                MATH::CVector3Array posArray = meshGridGeom.GetPoints().GetPositionArray();
                PointLocatorData pointLocators = NURBSGridGeom.GetClosestLocations(posArray.GetCount(), (double*)&posArray[0]);

                std::vector<float> data;
                NURBSGridGeom.EvaluateClusterProperty(pointLocators, -1, NULL, NURBSWeightMap2.GetParent(), NURBSWeightMap2, &data.front());

                for(LONG i = 0; i < posArray.GetCount(); i++)
                        posArray[i].PutY(posArray[i].GetY() + data[i]*5);

Inheritance diagram for PointLocatorData:

List of all members.

Public Member Functions

  PointLocatorData ()
  ~PointLocatorData ()
  PointLocatorData (const CRef &in_ref)
  PointLocatorData (const PointLocatorData &in_obj)
bool  IsA (siClassID in_ClassID) const
siClassID  GetClassID () const
PointLocatorData operator= (const PointLocatorData &in_obj)
PointLocatorData operator= (const CRef &in_ref)
LONG  GetCount () const
bool  IsPtLocatorValid (LONG i) const

Constructor & Destructor Documentation

Default constructor.

Default destructor.

PointLocatorData ( const CRef in_ref )


in_ref constant reference object.
PointLocatorData ( const PointLocatorData in_obj )

Copy constructor.

in_obj constant class object.

Member Function Documentation

bool IsA ( siClassID  in_ClassID ) const [virtual]

Returns true if a given class type is compatible with this API class.

in_ClassID class type.
true if the class is compatible, false otherwise.

Reimplemented from CBase.

siClassID GetClassID ( ) const [virtual]

Returns the type of the API class.

The class type.

Implements CBase.

PointLocatorData& operator= ( const PointLocatorData in_obj )

Creates an object from another object.

in_obj constant class object.
The new PointLocatorData object.
PointLocatorData& operator= ( const CRef in_ref )

Creates an object from a reference object. The newly created object is set to empty if the input reference object is not compatible.

in_ref constant class object.
The new PointLocatorData object.
LONG GetCount ( ) const

Returns the number of point locators contained in this object.

Number of point locators.
This example uses PointLocatorData to find closest vertices on a polygon mesh within a specific radius, and then creates a cluster on these points.
                Application app;
                Model root = app.GetActiveSceneRoot();
                X3DObject meshGridObj;
                root.AddGeometry( L"Grid", L"MeshSurface", L"", meshGridObj );
                PolygonMesh meshGridGeom( meshGridObj.GetActivePrimitive().GetGeometry() );

                CValueArray args(8);
                CValue outArg;
                args[0] = CValue(meshGridObj.GetRef());
                args[1] = CValue(L"0");
                args[2] = CValue(L"0");
                args[3] = CValue(L"-2");
                args[4] = CValue(L"siRelative");
                args[5] = CValue(L"siView");
                args[6] = CValue(L"siObj");
                args[7] = CValue(L"siXYZ");
                app.ExecuteCommand( L"Translate", args, outArg );

                // Set up to closest vertex search
                meshGridGeom.SetupPointLocatorQueries(siClosestVertexOrKnot, &meshGridObj.GetKinematics().GetGlobal().GetTransform(),-1,NULL,-1);

                // Get all vertices within a radius of 2 units relatively to the world center
                MATH::CVector3 positionToQuery(0,0,0);
                PointLocatorData pointLocatorsWithinTwoUnits = meshGridGeom.GetClosestLocationsWithinRadius(positionToQuery, 2.0);

                CLongArray indices;

                for(LONG i = 0; i < pointLocatorsWithinTwoUnits.GetCount(); i++)
                        // Even though the point locators have be defined to exactly match the vertex
                        // positions, the search data is returned as a position on a specific triangle,
                        // just as any other use of the Point Locator. However the vertex that matches
                        // can be determined because it will be weighted at 100%.
                        LONG subTriangleVertices[3];
                        meshGridGeom.GetTriangleVertexIndexArray(pointLocatorsWithinTwoUnits, 1, &i, subTriangleVertices);

                        float subTriangleWeights[3];
                        meshGridGeom.GetTriangleWeightArray(pointLocatorsWithinTwoUnits, 1, &i, subTriangleWeights);

                        LONG vtxIdx = subTriangleVertices[0];
                        if(subTriangleWeights[1] > subTriangleWeights[0] && subTriangleWeights[1] > subTriangleWeights[2])
                                vtxIdx = subTriangleVertices[1];
                        else if(subTriangleWeights[2] > subTriangleWeights[0] && subTriangleWeights[2] > subTriangleWeights[1])
                                vtxIdx = subTriangleVertices[2];

                // Create a cluster on these vertices
                Cluster vtxCluster;
                meshGridGeom.AddCluster(siVertexCluster, L"ClosestVertices", indices, vtxCluster);
bool IsPtLocatorValid ( LONG  i ) const

Returns true if a given point locator is valid. A point locator is invalid if, for instance, a call to Geometry::GetRaycastIntersections didn't find an intersection for a given ray.

i The index of the point locator.
True if the point locator is valid; false otherwise.

The documentation for this class was generated from the following file: