my test demo

[xuechengang]

  NFP[] nfps = new NFP[13];
  nfps[0] = new NFP();
  nfps[0].AddPoint(new SvgPoint(1, 1));
  nfps[0].AddPoint(new SvgPoint(12, 12));
  nfps[0].AddPoint(new SvgPoint(1, 10));
  nfps[1] = new NFP();
  nfps[1].AddPoint(new SvgPoint(10, 10));
  nfps[1].AddPoint(new SvgPoint(22, 22));
  nfps[1].AddPoint(new SvgPoint(10, 20));
  nfps[2] = new NFP();
  nfps[2].AddPoint(new SvgPoint(20, 20));
  nfps[2].AddPoint(new SvgPoint(32, 32));
  nfps[2].AddPoint(new SvgPoint(20, 30));
  for (int i = 3; i < 13; i++)
  {
      nfps[i] = new NFP();
      nfps[i].AddPoint(new SvgPoint(10, 10));
      nfps[i].AddPoint(new SvgPoint(22, 22));
      nfps[i].AddPoint(new SvgPoint(10, 20));
  }

  StartParallel(100, 100, 20, 2, nfps);

//
// call run
//

        public List<NFP> StartParallel(double binW, double binH,
            int loopCount, double spacing, NFP[] nestPaths)
{
double newBinW = binW;
double newBinH = binH;
SvgNest.Config.spacing = spacing;
SvgNest.Config.placementType = PlacementTypeEnum.gravity;
//SvgNest.Config.rotations = isHighSpeed ? 2 : 5;
SvgNest.Config.rotations = 5;
SvgNest.Config.sheetSpacing = spacing * 0.5d;
//SvgNest.Config.useHoles = true;
DeepNestLib.Background.UseParallel = true;
NestingContext nc = new NestingContext();

nc.AddSheet((int)binW, (int)binH, 0);
nc.Polygons.AddRange(nestPaths);
nc.StartNest();
double bestFitness = double.MaxValue;
List<SheetPlacementItem>[] best_placements = null;
for (int i = 0; i < loopCount; i++)
{
    nc.NestIterate();
    if (nc.Current.fitness < bestFitness)
    {
        bestFitness = nc.Current.fitness.Value;
        best_placements = nc.Current.placements;
    }
}
SvgParser.Export("output.svg", nc.Polygons, nc.Sheets);

return nc.Polygons;
}

//output.svg

[fel88]

Hi! Please take a look at DeepNestConsole.Core
This is probably what you need

[xuechengang]

When I write like this (nfp. source=i), it runs normally.