The following two examples demonstrate two approaches that can be used to create a double array. The both achieve effectively the same result.

1. This function demonstrates a way to create a double array of nodes, a nested child node:

   By creating a collection of point and then a collection of points within that collection. Then by passing no arguments to the child node's constructor, then returning the child node as the result of the function.

   transaction 1 modelChange 'Initialize bsplineSurface01'
   {
       node User.Objects.coordinateSystem1 Bentley.GC.NodeTypes.CoordinateSystem
       {
           Technique                 = 'AtModelOrigin';
           GraphLocation             = <auto> {40.0, 40.0};
       }
       node User.Objects.coordinateSystem1 Bentley.GC.NodeTypes.CoordinateSystem
       {
           Technique                 = 'AtModelOrigin';
           DGNModelName              = '3D Metric Design';
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = <free> 0.0;
           YTranslation              = <free> 0.0;
           ZTranslation              = <free> 0.0;
           GraphLocation             = <auto> {314.0, 40.0};
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = <free> 0.0;
           YTranslation              = <free> 0.0;
           ZTranslation              = <free> 0.0;
           GraphLocation             = <auto> {314.0, 235.87};
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = 10;
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           YTranslation              = Series(0,10,1);
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           GraphLocation             = {319.0, 189.87};
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           ZTranslation              = Series(0,10,1);
       }
       node User.Objects.bsplineSurface01 Bentley.GC.NodeTypes.BSplineSurface
       {
           Technique                 = 'ByPoints';
           GraphLocation             = <auto> {588.0, 40.0};
       }
       node User.Objects.bsplineSurface01 Bentley.GC.NodeTypes.BSplineSurface
       {
           Technique                 = 'ByPoints';
           Points                    = {point1, point2};
       }
   }
   
   transaction 2 modelChange 'Point on surface'
   {
       node User.Objects.point10 Bentley.GC.NodeTypes.Point
       {
           Function                  = Point function (BSplineSurface surface, int numU, int numV)
                                       {
                                       double uSpacing = 1.0/numU;
                                       double vSpacing = 1.0/numV;
                                       Point pt = {};
                                       for (int i = 0; i <= numU; ++i)
                                       {
                                       pt[i] = {};
                                       for (int j = 0; j <= numV; ++j)
                                       {
                                       pt[i][j] = new Point();
                                       pt[i][j].ByUVParametersOnSurface(surface,uSpacing*i, vSpacing*j);
                                       }
                                       }
                                       return pt;
                                       };
           FunctionArguments         = {bsplineSurface01, 4, 4};
       }
   }

2. This function demonstrates a way to create a nested child node:

   First a child node is created within a loop by passing 'this' to the child node's constructor. Then a nested child node is created within a second loop by passing the name of the child node to the nested child node's constructor. In this example of created a double array of points on a BSplineSurface the child node is called collectionPoint and the nested child node is named nestedPoint.

   transaction 1 modelChange 'Initialize bsplineSurface01'
   {
       node User.Objects.coordinateSystem1 Bentley.GC.NodeTypes.CoordinateSystem
       {
           Technique                 = 'AtModelOrigin';
           GraphLocation             = <auto> {40.0, 40.0};
       }
       node User.Objects.coordinateSystem1 Bentley.GC.NodeTypes.CoordinateSystem
       {
           Technique                 = 'AtModelOrigin';
           DGNModelName              = '3D Metric Design';
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = <free> 0.0;
           YTranslation              = <free> 0.0;
           ZTranslation              = <free> 0.0;
           GraphLocation             = <auto> {314.0, 40.0};
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = <free> 0.0;
           YTranslation              = <free> 0.0;
           ZTranslation              = <free> 0.0;
           GraphLocation             = <auto> {314.0, 235.87};
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           XTranslation              = 10;
       }
       node User.Objects.point1 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           YTranslation              = Series(0,10,1);
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           GraphLocation             = {319.0, 189.87};
       }
       node User.Objects.point2 Bentley.GC.NodeTypes.Point
       {
           Technique                 = 'ByCartesianCoordinates';
           ZTranslation              = Series(0,10,1);
       }
       node User.Objects.bsplineSurface01 Bentley.GC.NodeTypes.BSplineSurface
       {
           Technique                 = 'ByPoints';
           GraphLocation             = <auto> {588.0, 40.0};
       }
       node User.Objects.bsplineSurface01 Bentley.GC.NodeTypes.BSplineSurface
       {
           Technique                 = 'ByPoints';
           Points                    = {point1, point2};
       }
   }
   
   transaction 2 modelChange 'Point on surface'
   {
       node User.Objects.pointOnSurface Bentley.GC.NodeTypes.Point
       {
           Function                  = function (BSplineSurface surface, int numU, int numV) 
                                       {
                                       double uSpacing = 1.0/numU; 
                                       double vSpacing = 1.0/numV; 
                                       for (int i = 0; i <= numU; ++i) 
                                       {
                                       Point collectionPoint = new Point(this); 
                                       for (int j = 0; j <= numV; ++j)
                                       {
                                       Point nestedPoint = new Point(collectionPoint); 
                                       nestedPoint.ByUVParametersOnSurface(surface,
                                       uSpacing*i, vSpacing*j); 
                                       }
                                       }
                                        
                                       };
           FunctionArguments         = {bsplineSurface01, 4, 4};
       }
   }