refactor: extract training data collection into OpenNest.Training

Move brute-force data collection, TrainingDatabase, and GPU init from
OpenNest.Console into a dedicated OpenNest.Training project. Replaces
raw Microsoft.Data.Sqlite with EF Core. Console is now a pure nesting
CLI with template support and cleaned-up usage output.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Console/OpenNest.Console.csproj

@@ -10,9 +10,5 @@
     <ProjectReference Include="..\OpenNest.Core\OpenNest.Core.csproj" />
     <ProjectReference Include="..\OpenNest.Engine\OpenNest.Engine.csproj" />
     <ProjectReference Include="..\OpenNest.IO\OpenNest.IO.csproj" />
-    <ProjectReference Include="..\OpenNest.Gpu\OpenNest.Gpu.csproj" />
-  </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Data.Sqlite" Version="10.0.5" />
   </ItemGroup>
 </Project>

OpenNest.Console/Program.cs

@@ -6,11 +6,6 @@ using System.Linq;
 using OpenNest;
 using OpenNest.Geometry;
 using OpenNest.IO;
-using Color = System.Drawing.Color;
-using OpenNest.Console;
-using OpenNest.Engine.BestFit;
-using OpenNest.Engine.ML;
-using OpenNest.Gpu;
 
 // Parse arguments.
 var nestFile = (string)null;
@@ -26,27 +21,12 @@ var noSave = false;
 var noLog = false;
 var keepParts = false;
 var autoNest = false;
-var collectDataDir = (string)null;
-var dbPath = "nesting_training.db";
-var saveNestsDir = (string)null;
 var templateFile = (string)null;
 
 for (var i = 0; i < args.Length; i++)
 {
     switch (args[i])
     {
-        case "--db" when i + 1 < args.Length:
-            dbPath = args[++i];
-            break;
-        case "--save-nests" when i + 1 < args.Length:
-            saveNestsDir = args[++i];
-            break;
-        case "--template" when i + 1 < args.Length:
-            templateFile = args[++i];
-            break;
-        case "--collect" when i + 1 < args.Length:
-            collectDataDir = args[++i];
-            break;
         case "--drawing" when i + 1 < args.Length:
             drawingName = args[++i];
             break;
@@ -82,6 +62,9 @@ for (var i = 0; i < args.Length; i++)
         case "--keep-parts":
             keepParts = true;
             break;
+        case "--template" when i + 1 < args.Length:
+            templateFile = args[++i];
+            break;
         case "--autonest":
             autoNest = true;
             break;
@@ -96,22 +79,6 @@ for (var i = 0; i < args.Length; i++)
     }
 }
 
-// Initialize GPU if available.
-if (GpuEvaluatorFactory.GpuAvailable)
-{
-    BestFitCache.CreateSlideComputer = () => GpuEvaluatorFactory.CreateSlideComputer();
-    Console.WriteLine($"GPU: {GpuEvaluatorFactory.DeviceName}");
-}
-else
-{
-    Console.WriteLine("GPU: not available (using CPU)");
-}
-
-if (collectDataDir != null)
-{
-    return RunDataCollection(collectDataDir, dbPath, saveNestsDir, spacing ?? 0.5, templateFile);
-}
-
 if (string.IsNullOrEmpty(nestFile) || !File.Exists(nestFile))
 {
     PrintUsage();
@@ -149,6 +116,24 @@ if (plateIndex >= nest.Plates.Count)
 
 var plate = nest.Plates[plateIndex];
 
+// Apply template defaults.
+if (templateFile != null)
+{
+    if (!File.Exists(templateFile))
+    {
+        Console.Error.WriteLine($"Error: Template not found: {templateFile}");
+        return 1;
+    }
+    var templateNest = new NestReader(templateFile).Read();
+    var templatePlate = templateNest.PlateDefaults.CreateNew();
+    plate.Thickness = templatePlate.Thickness;
+    plate.Quadrant = templatePlate.Quadrant;
+    plate.Material = templatePlate.Material;
+    plate.EdgeSpacing = templatePlate.EdgeSpacing;
+    plate.PartSpacing = templatePlate.PartSpacing;
+    Console.WriteLine($"Template: {templateFile}");
+}
+
 // Apply overrides.
 if (spacing.HasValue)
     plate.PartSpacing = spacing.Value;
@@ -207,9 +192,9 @@ if (autoNest)
 
     Console.WriteLine($"AutoNest: {nestItems.Count} drawing(s), {nestItems.Sum(i => i.Quantity)} total parts");
 
-    var parts = NestEngine.AutoNest(nestItems, plate);
+    var nestParts = NestEngine.AutoNest(nestItems, plate);
-    plate.Parts.AddRange(parts);
+    plate.Parts.AddRange(nestParts);
-    success = parts.Count > 0;
+    success = nestParts.Count > 0;
 }
 else
 {
@@ -262,253 +247,25 @@ if (!noSave)
 
 return checkOverlaps && overlapCount > 0 ? 1 : 0;
 
-int RunDataCollection(string dir, string dbPath, string saveDir, double s, string template)
-{
-    if (!Directory.Exists(dir))
-    {
-        Console.Error.WriteLine($"Error: Directory not found: {dir}");
-        return 1;
-    }
-
-    // Load template nest for plate defaults if provided.
-    Nest templateNest = null;
-    if (template != null)
-    {
-        if (!File.Exists(template))
-        {
-            Console.Error.WriteLine($"Error: Template not found: {template}");
-            return 1;
-        }
-        templateNest = new NestReader(template).Read();
-        Console.WriteLine($"Using template: {template}");
-    }
-
-    var PartColors = new[]
-    {
-        Color.FromArgb(205, 92, 92),
-        Color.FromArgb(148, 103, 189),
-        Color.FromArgb(75, 180, 175),
-        Color.FromArgb(210, 190, 75),
-        Color.FromArgb(190, 85, 175),
-        Color.FromArgb(185, 115, 85),
-        Color.FromArgb(120, 100, 190),
-        Color.FromArgb(200, 100, 140),
-        Color.FromArgb(80, 175, 155),
-        Color.FromArgb(195, 160, 85),
-        Color.FromArgb(175, 95, 160),
-        Color.FromArgb(215, 130, 130),
-    };
-
-    var sheetSuite = new[]
-    {
-        new Size(96, 48), new Size(120, 48), new Size(144, 48),
-        new Size(96, 60), new Size(120, 60), new Size(144, 60),
-        new Size(96, 72), new Size(120, 72), new Size(144, 72),
-        new Size(48, 24), new Size(120, 10)
-    };
-
-    var dxfFiles = Directory.GetFiles(dir, "*.dxf", SearchOption.AllDirectories);
-    Console.WriteLine($"Found {dxfFiles.Length} DXF files");
-    Console.WriteLine($"Database: {Path.GetFullPath(dbPath)}");
-    Console.WriteLine($"Sheet sizes: {sheetSuite.Length} configurations");
-    Console.WriteLine($"Spacing: {s:F2}");
-    if (saveDir != null) Console.WriteLine($"Saving nests to: {saveDir}");
-    Console.WriteLine("---");
-
-    using var db = new TrainingDatabase(dbPath);
-
-    var importer = new DxfImporter();
-    var colorIndex = 0;
-    var processed = 0;
-    var skippedGeometry = 0;
-    var skippedFeatures = 0;
-    var skippedExisting = 0;
-    var totalRuns = 0;
-    var totalSw = Stopwatch.StartNew();
-
-    foreach (var file in dxfFiles)
-    {
-        var fileNum = processed + skippedGeometry + skippedFeatures + skippedExisting + 1;
-        var partNo = Path.GetFileNameWithoutExtension(file);
-        Console.Write($"[{fileNum}/{dxfFiles.Length}] {partNo}");
-
-        try
-        {
-            var existingRuns = db.RunCount(Path.GetFileName(file));
-            if (existingRuns >= sheetSuite.Length)
-            {
-                Console.WriteLine(" - SKIP (all sizes done)");
-                skippedExisting++;
-                continue;
-            }
-
-            if (!importer.GetGeometry(file, out var entities))
-            {
-                Console.WriteLine(" - SKIP (no geometry)");
-                skippedGeometry++;
-                continue;
-            }
-
-            var drawing = new Drawing(Path.GetFileName(file));
-            drawing.Program = OpenNest.Converters.ConvertGeometry.ToProgram(entities);
-            drawing.UpdateArea();
-            drawing.Color = PartColors[colorIndex % PartColors.Length];
-            colorIndex++;
-
-            var features = FeatureExtractor.Extract(drawing);
-            if (features == null)
-            {
-                Console.WriteLine(" - SKIP (feature extraction failed)");
-                skippedFeatures++;
-                continue;
-            }
-
-            Console.WriteLine($" (area={features.Area:F1}, verts={features.VertexCount})");
-
-            // Precompute best-fits once for all sheet sizes.
-            var sizes = sheetSuite.Select(sz => (sz.Width, sz.Length)).ToList();
-            var bfSw = Stopwatch.StartNew();
-            BestFitCache.ComputeForSizes(drawing, s, sizes);
-            bfSw.Stop();
-            Console.WriteLine($"  Best-fits computed in {bfSw.ElapsedMilliseconds}ms");
-
-            using var txn = db.BeginTransaction();
-
-            var partId = db.GetOrAddPart(Path.GetFileName(file), features, drawing.Program.ToString());
-            var partSw = Stopwatch.StartNew();
-            var runsThisPart = 0;
-            var bestUtil = 0.0;
-            var bestCount = 0;
-
-            foreach (var size in sheetSuite)
-            {
-                if (db.HasRun(Path.GetFileName(file), size.Width, size.Length, s))
-                {
-                    Console.WriteLine($"  {size.Length}x{size.Width} - skip (exists)");
-                    continue;
-                }
-
-                Plate runPlate;
-                if (templateNest != null)
-                {
-                    runPlate = templateNest.PlateDefaults.CreateNew();
-                    runPlate.Size = size;
-                    runPlate.PartSpacing = s;
-                }
-                else
-                {
-                    runPlate = new Plate { Size = size, PartSpacing = s };
-                }
-
-                var sizeSw = Stopwatch.StartNew();
-                var result = BruteForceRunner.Run(drawing, runPlate);
-                sizeSw.Stop();
-
-                if (result == null)
-                {
-                    Console.WriteLine($"  {size.Length}x{size.Width} - no fit");
-                    continue;
-                }
-
-                if (result.Utilization > bestUtil)
-                {
-                    bestUtil = result.Utilization;
-                    bestCount = result.PartCount;
-                }
-
-                Console.WriteLine($"  {size.Length}x{size.Width} - {result.PartCount}pcs, {result.Utilization:P1}, {sizeSw.ElapsedMilliseconds}ms");
-
-                string savedFilePath = null;
-                if (saveDir != null)
-                {
-                    // Deterministic bucket (00-FF) based on filename hash
-                    uint hash = 0;
-                    foreach (char c in partNo) hash = (hash * 31) + c;
-                    var bucket = (hash % 256).ToString("X2");
-
-                    var partDir = Path.Combine(saveDir, bucket, partNo);
-                    Directory.CreateDirectory(partDir);
-
-                    var nestName = $"{partNo}-{size.Length}x{size.Width}-{result.PartCount}pcs";
-                    var fileName = nestName + ".zip";
-                    savedFilePath = Path.Combine(partDir, fileName);
-
-                    // Create nest from template or from scratch
-                    Nest nestObj;
-                    if (templateNest != null)
-                    {
-                        nestObj = new Nest(nestName)
-                        {
-                            Units = templateNest.Units,
-                            DateCreated = DateTime.Now
-                        };
-                        nestObj.PlateDefaults.SetFromExisting(templateNest.PlateDefaults.CreateNew());
-                    }
-                    else
-                    {
-                        nestObj = new Nest(nestName) { Units = Units.Inches, DateCreated = DateTime.Now };
-                    }
-
-                    nestObj.Drawings.Add(drawing);
-                    var plateObj = nestObj.CreatePlate();
-                    plateObj.Size = size;
-                    plateObj.PartSpacing = s;
-                    plateObj.Parts.AddRange(result.PlacedParts);
-
-                    var writer = new NestWriter(nestObj);
-                    writer.Write(savedFilePath);
-                }
-
-                db.AddRun(partId, size.Width, size.Length, s, result, savedFilePath);
-                runsThisPart++;
-                totalRuns++;
-            }
-
-            txn.Commit();
-            BestFitCache.Invalidate(drawing);
-            partSw.Stop();
-            processed++;
-            Console.WriteLine($"  Total: {runsThisPart} runs, best={bestCount}pcs @ {bestUtil:P1}, {partSw.ElapsedMilliseconds}ms");
-        }
-        catch (Exception ex)
-        {
-            Console.WriteLine();
-            Console.Error.WriteLine($"  ERROR: {ex.Message}");
-        }
-    }
-
-    totalSw.Stop();
-    Console.WriteLine("---");
-    Console.WriteLine($"Processed: {processed} parts, {totalRuns} total runs");
-    Console.WriteLine($"Skipped:   {skippedExisting} (existing) + {skippedGeometry} (no geometry) + {skippedFeatures} (no features)");
-    Console.WriteLine($"Time:      {totalSw.Elapsed:h\\:mm\\:ss}");
-    Console.WriteLine($"Database:  {Path.GetFullPath(dbPath)}");
-    return 0;
-}
-
 void PrintUsage()
 {
     Console.Error.WriteLine("Usage: OpenNest.Console <nest-file> [options]");
-    Console.Error.WriteLine("       OpenNest.Console --collect <dxf-dir> [options]");
     Console.Error.WriteLine();
     Console.Error.WriteLine("Arguments:");
     Console.Error.WriteLine("  nest-file              Path to a .zip nest file");
     Console.Error.WriteLine();
     Console.Error.WriteLine("Options:");
     Console.Error.WriteLine("  --drawing <name>       Drawing name to fill with (default: first drawing)");
-    Console.WriteLine("  --plate <index>        Plate index to fill (default: 0)");
+    Console.Error.WriteLine("  --plate <index>        Plate index to fill (default: 0)");
-    Console.WriteLine("  --quantity <n>          Max parts to place (default: 0 = unlimited)");
+    Console.Error.WriteLine("  --quantity <n>          Max parts to place (default: 0 = unlimited)");
-    Console.WriteLine("  --spacing <value>      Override part spacing");
+    Console.Error.WriteLine("  --spacing <value>      Override part spacing");
-    Console.WriteLine("  --size <WxH>           Override plate size (e.g. 120x60)");
+    Console.Error.WriteLine("  --size <WxH>           Override plate size (e.g. 120x60)");
-    Console.WriteLine("  --output <path>        Output nest file path (default: <input>-result.zip)");
+    Console.Error.WriteLine("  --output <path>        Output nest file path (default: <input>-result.zip)");
-    Console.WriteLine("  --autonest             Use NFP-based mixed-part autonesting instead of linear fill");
+    Console.Error.WriteLine("  --template <path>      Nest template for plate defaults (thickness, quadrant, material, spacing)");
-    Console.WriteLine("  --keep-parts           Don't clear existing parts before filling");
+    Console.Error.WriteLine("  --autonest             Use NFP-based mixed-part autonesting instead of linear fill");
-    Console.WriteLine("  --check-overlaps       Run overlap detection after fill (exit code 1 if found)");
+    Console.Error.WriteLine("  --keep-parts           Don't clear existing parts before filling");
-    Console.WriteLine("  --no-save              Skip saving output file");
+    Console.Error.WriteLine("  --check-overlaps       Run overlap detection after fill (exit code 1 if found)");
-    Console.WriteLine("  --no-log               Skip writing debug log file");
+    Console.Error.WriteLine("  --no-save              Skip saving output file");
-    Console.WriteLine("  --collect <dir>        Brute-force process all DXFs in directory to SQLite");
+    Console.Error.WriteLine("  --no-log               Skip writing debug log file");
-    Console.WriteLine("  --db <path>            Path to the SQLite training database (default: nesting_training.db)");
+    Console.Error.WriteLine("  -h, --help             Show this help");
-    Console.WriteLine("  --save-nests <dir>     Directory to save individual .zip nests for each winner");
-    Console.WriteLine("  --template <path>      Nest template (.nstdot) for plate defaults");
-    Console.WriteLine("  -h, --help             Show this help");
 }

OpenNest.Console/TrainingDatabase.cs

@@ -1,145 +0,0 @@
-using System;
-using Microsoft.Data.Sqlite;
-using OpenNest.Engine.ML;
-
-namespace OpenNest.Console
-{
-    public class TrainingDatabase : IDisposable
-    {
-        private readonly SqliteConnection _connection;
-
-        public TrainingDatabase(string dbPath)
-        {
-            var connectionString = new SqliteConnectionStringBuilder
-            {
-                DataSource = dbPath,
-                Mode = SqliteOpenMode.ReadWriteCreate
-            }.ToString();
-
-            _connection = new SqliteConnection(connectionString);
-            _connection.Open();
-
-            InitializeSchema();
-        }
-
-        private void InitializeSchema()
-        {
-            using var cmd = _connection.CreateCommand();
-            cmd.CommandText = @"
-                CREATE TABLE IF NOT EXISTS Parts (
-                    Id INTEGER PRIMARY KEY AUTOINCREMENT,
-                    FileName TEXT,
-                    Area REAL,
-                    Convexity REAL,
-                    AspectRatio REAL,
-                    BBFill REAL,
-                    Circularity REAL,
-                    VertexCount INTEGER,
-                    Bitmask BLOB,
-                    GeometryData TEXT
-                );
-
-                CREATE TABLE IF NOT EXISTS Runs (
-                    Id INTEGER PRIMARY KEY AUTOINCREMENT,
-                    PartId INTEGER,
-                    SheetWidth REAL,
-                    SheetHeight REAL,
-                    Spacing REAL,
-                    PartCount INTEGER,
-                    Utilization REAL,
-                    TimeMs INTEGER,
-                    LayoutData TEXT,
-                    FilePath TEXT,
-                    FOREIGN KEY(PartId) REFERENCES Parts(Id)
-                );
-
-                CREATE INDEX IF NOT EXISTS idx_parts_filename ON Parts(FileName);
-                CREATE INDEX IF NOT EXISTS idx_runs_partid ON Runs(PartId);
-            ";
-            cmd.ExecuteNonQuery();
-        }
-
-        public long GetOrAddPart(string fileName, PartFeatures features, string geometryData)
-        {
-            // Check if part already exists
-            using (var checkCmd = _connection.CreateCommand())
-            {
-                checkCmd.CommandText = "SELECT Id FROM Parts WHERE FileName = @name";
-                checkCmd.Parameters.AddWithValue("@name", fileName);
-                var result = checkCmd.ExecuteScalar();
-                if (result != null) return (long)result;
-            }
-
-            // Add new part
-            using (var insertCmd = _connection.CreateCommand())
-            {
-                insertCmd.CommandText = @"
-                    INSERT INTO Parts (FileName, Area, Convexity, AspectRatio, BBFill, Circularity, VertexCount, Bitmask, GeometryData)
-                    VALUES (@name, @area, @conv, @asp, @fill, @circ, @vert, @mask, @geo);
-                    SELECT last_insert_rowid();";
-
-                insertCmd.Parameters.AddWithValue("@name", fileName);
-                insertCmd.Parameters.AddWithValue("@area", features.Area);
-                insertCmd.Parameters.AddWithValue("@conv", features.Convexity);
-                insertCmd.Parameters.AddWithValue("@asp", features.AspectRatio);
-                insertCmd.Parameters.AddWithValue("@fill", features.BoundingBoxFill);
-                insertCmd.Parameters.AddWithValue("@circ", features.Circularity);
-                insertCmd.Parameters.AddWithValue("@vert", features.VertexCount);
-                insertCmd.Parameters.AddWithValue("@mask", features.Bitmask);
-                insertCmd.Parameters.AddWithValue("@geo", geometryData);
-
-                return (long)insertCmd.ExecuteScalar();
-            }
-        }
-
-        public bool HasRun(string fileName, double sheetWidth, double sheetHeight, double spacing)
-        {
-            using var cmd = _connection.CreateCommand();
-            cmd.CommandText = @"SELECT COUNT(*) FROM Runs r JOIN Parts p ON r.PartId = p.Id
-                WHERE p.FileName = @name AND r.SheetWidth = @w AND r.SheetHeight = @h AND r.Spacing = @s";
-            cmd.Parameters.AddWithValue("@name", fileName);
-            cmd.Parameters.AddWithValue("@w", sheetWidth);
-            cmd.Parameters.AddWithValue("@h", sheetHeight);
-            cmd.Parameters.AddWithValue("@s", spacing);
-            return (long)cmd.ExecuteScalar() > 0;
-        }
-
-        public int RunCount(string fileName)
-        {
-            using var cmd = _connection.CreateCommand();
-            cmd.CommandText = "SELECT COUNT(*) FROM Runs r JOIN Parts p ON r.PartId = p.Id WHERE p.FileName = @name";
-            cmd.Parameters.AddWithValue("@name", fileName);
-            return (int)(long)cmd.ExecuteScalar();
-        }
-
-        public void AddRun(long partId, double w, double h, double s, BruteForceResult result, string filePath)
-        {
-            using var cmd = _connection.CreateCommand();
-            cmd.CommandText = @"
-                INSERT INTO Runs (PartId, SheetWidth, SheetHeight, Spacing, PartCount, Utilization, TimeMs, LayoutData, FilePath)
-                VALUES (@pid, @w, @h, @s, @cnt, @util, @time, @layout, @path)";
-
-            cmd.Parameters.AddWithValue("@pid", partId);
-            cmd.Parameters.AddWithValue("@w", w);
-            cmd.Parameters.AddWithValue("@h", h);
-            cmd.Parameters.AddWithValue("@s", s);
-            cmd.Parameters.AddWithValue("@cnt", result.PartCount);
-            cmd.Parameters.AddWithValue("@util", result.Utilization);
-            cmd.Parameters.AddWithValue("@time", result.TimeMs);
-            cmd.Parameters.AddWithValue("@layout", result.LayoutData ?? "");
-            cmd.Parameters.AddWithValue("@path", filePath ?? "");
-
-            cmd.ExecuteNonQuery();
-        }
-
-        public SqliteTransaction BeginTransaction()
-        {
-            return _connection.BeginTransaction();
-        }
-
-        public void Dispose()
-        {
-            _connection?.Dispose();
-        }
-    }
-}

OpenNest.Training/Data/TrainingDbContext.cs

@@ -0,0 +1,38 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace OpenNest.Training.Data
+{
+    public class TrainingDbContext : DbContext
+    {
+        public DbSet<TrainingPart> Parts { get; set; }
+        public DbSet<TrainingRun> Runs { get; set; }
+
+        private readonly string _dbPath;
+
+        public TrainingDbContext(string dbPath)
+        {
+            _dbPath = dbPath;
+        }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder options)
+        {
+            options.UseSqlite($"Data Source={_dbPath}");
+        }
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<TrainingPart>(e =>
+            {
+                e.HasIndex(p => p.FileName).HasDatabaseName("idx_parts_filename");
+            });
+
+            modelBuilder.Entity<TrainingRun>(e =>
+            {
+                e.HasIndex(r => r.PartId).HasDatabaseName("idx_runs_partid");
+                e.HasOne(r => r.Part)
+                    .WithMany(p => p.Runs)
+                    .HasForeignKey(r => r.PartId);
+            });
+        }
+    }
+}

OpenNest.Training/Data/TrainingPart.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace OpenNest.Training.Data
+{
+    [Table("Parts")]
+    public class TrainingPart
+    {
+        [Key]
+        public long Id { get; set; }
+
+        [MaxLength(260)]
+        public string FileName { get; set; }
+
+        public double Area { get; set; }
+        public double Convexity { get; set; }
+        public double AspectRatio { get; set; }
+        public double BBFill { get; set; }
+        public double Circularity { get; set; }
+        public double PerimeterToAreaRatio { get; set; }
+        public int VertexCount { get; set; }
+        public byte[] Bitmask { get; set; }
+        public string GeometryData { get; set; }
+
+        public List<TrainingRun> Runs { get; set; } = new();
+    }
+}

OpenNest.Training/Data/TrainingRun.cs

@@ -0,0 +1,25 @@
+using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace OpenNest.Training.Data
+{
+    [Table("Runs")]
+    public class TrainingRun
+    {
+        [Key]
+        public long Id { get; set; }
+
+        public long PartId { get; set; }
+        public double SheetWidth { get; set; }
+        public double SheetHeight { get; set; }
+        public double Spacing { get; set; }
+        public int PartCount { get; set; }
+        public double Utilization { get; set; }
+        public long TimeMs { get; set; }
+        public string LayoutData { get; set; }
+        public string FilePath { get; set; }
+
+        [ForeignKey(nameof(PartId))]
+        public TrainingPart Part { get; set; }
+    }
+}

OpenNest.Training/OpenNest.Training.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <RootNamespace>OpenNest.Training</RootNamespace>
+    <AssemblyName>OpenNest.Training</AssemblyName>
+    <DefineConstants>$(DefineConstants);DEBUG;TRACE</DefineConstants>
+  </PropertyGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\OpenNest.Core\OpenNest.Core.csproj" />
+    <ProjectReference Include="..\OpenNest.Engine\OpenNest.Engine.csproj" />
+    <ProjectReference Include="..\OpenNest.IO\OpenNest.IO.csproj" />
+    <ProjectReference Include="..\OpenNest.Gpu\OpenNest.Gpu.csproj" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.10" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.10" />
+  </ItemGroup>
+</Project>

OpenNest.Training/Program.cs

@@ -0,0 +1,300 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using OpenNest;
+using OpenNest.Geometry;
+using OpenNest.IO;
+using Color = System.Drawing.Color;
+using OpenNest.Engine.BestFit;
+using OpenNest.Engine.ML;
+using OpenNest.Gpu;
+using OpenNest.Training;
+
+// Parse arguments.
+var dbPath = "OpenNestTraining";
+var saveNestsDir = (string)null;
+var templateFile = (string)null;
+var spacing = 0.5;
+var collectDir = (string)null;
+
+for (var i = 0; i < args.Length; i++)
+{
+    switch (args[i])
+    {
+        case "--db" when i + 1 < args.Length:
+            dbPath = args[++i];
+            break;
+        case "--save-nests" when i + 1 < args.Length:
+            saveNestsDir = args[++i];
+            break;
+        case "--template" when i + 1 < args.Length:
+            templateFile = args[++i];
+            break;
+        case "--spacing" when i + 1 < args.Length:
+            spacing = double.Parse(args[++i]);
+            break;
+        case "--help":
+        case "-h":
+            PrintUsage();
+            return 0;
+        default:
+            if (!args[i].StartsWith("--") && collectDir == null)
+                collectDir = args[i];
+            break;
+    }
+}
+
+if (string.IsNullOrEmpty(collectDir) || !Directory.Exists(collectDir))
+{
+    PrintUsage();
+    return 1;
+}
+
+// Initialize GPU if available.
+if (GpuEvaluatorFactory.GpuAvailable)
+{
+    BestFitCache.CreateSlideComputer = () => GpuEvaluatorFactory.CreateSlideComputer();
+    Console.WriteLine($"GPU: {GpuEvaluatorFactory.DeviceName}");
+}
+else
+{
+    Console.WriteLine("GPU: not available (using CPU)");
+}
+
+return RunDataCollection(collectDir, dbPath, saveNestsDir, spacing, templateFile);
+
+int RunDataCollection(string dir, string dbPath, string saveDir, double s, string template)
+{
+    // Load template nest for plate defaults if provided.
+    Nest templateNest = null;
+    if (template != null)
+    {
+        if (!File.Exists(template))
+        {
+            Console.Error.WriteLine($"Error: Template not found: {template}");
+            return 1;
+        }
+        templateNest = new NestReader(template).Read();
+        Console.WriteLine($"Using template: {template}");
+    }
+
+    var PartColors = new[]
+    {
+        Color.FromArgb(205, 92, 92),
+        Color.FromArgb(148, 103, 189),
+        Color.FromArgb(75, 180, 175),
+        Color.FromArgb(210, 190, 75),
+        Color.FromArgb(190, 85, 175),
+        Color.FromArgb(185, 115, 85),
+        Color.FromArgb(120, 100, 190),
+        Color.FromArgb(200, 100, 140),
+        Color.FromArgb(80, 175, 155),
+        Color.FromArgb(195, 160, 85),
+        Color.FromArgb(175, 95, 160),
+        Color.FromArgb(215, 130, 130),
+    };
+
+    var sheetSuite = new[]
+    {
+        new Size(96, 48), new Size(120, 48), new Size(144, 48),
+        new Size(96, 60), new Size(120, 60), new Size(144, 60),
+        new Size(96, 72), new Size(120, 72), new Size(144, 72),
+        new Size(48, 24), new Size(120, 10)
+    };
+
+    var dxfFiles = Directory.GetFiles(dir, "*.dxf", SearchOption.AllDirectories);
+    Console.WriteLine($"Found {dxfFiles.Length} DXF files");
+    var resolvedDb = dbPath.EndsWith(".db", StringComparison.OrdinalIgnoreCase) ? dbPath : dbPath + ".db";
+    Console.WriteLine($"Database: {Path.GetFullPath(resolvedDb)}");
+    Console.WriteLine($"Sheet sizes: {sheetSuite.Length} configurations");
+    Console.WriteLine($"Spacing: {s:F2}");
+    if (saveDir != null) Console.WriteLine($"Saving nests to: {saveDir}");
+    Console.WriteLine("---");
+
+    using var db = new TrainingDatabase(dbPath);
+
+    var backfilled = db.BackfillPerimeterToAreaRatio();
+    if (backfilled > 0)
+        Console.WriteLine($"Backfilled PerimeterToAreaRatio for {backfilled} existing parts");
+
+    var importer = new DxfImporter();
+    var colorIndex = 0;
+    var processed = 0;
+    var skippedGeometry = 0;
+    var skippedFeatures = 0;
+    var skippedExisting = 0;
+    var totalRuns = 0;
+    var totalSw = Stopwatch.StartNew();
+
+    foreach (var file in dxfFiles)
+    {
+        var fileNum = processed + skippedGeometry + skippedFeatures + skippedExisting + 1;
+        var partNo = Path.GetFileNameWithoutExtension(file);
+        Console.Write($"[{fileNum}/{dxfFiles.Length}] {partNo}");
+
+        try
+        {
+            var existingRuns = db.RunCount(Path.GetFileName(file));
+            if (existingRuns >= sheetSuite.Length)
+            {
+                Console.WriteLine(" - SKIP (all sizes done)");
+                skippedExisting++;
+                continue;
+            }
+
+            if (!importer.GetGeometry(file, out var entities))
+            {
+                Console.WriteLine(" - SKIP (no geometry)");
+                skippedGeometry++;
+                continue;
+            }
+
+            var drawing = new Drawing(Path.GetFileName(file));
+            drawing.Program = OpenNest.Converters.ConvertGeometry.ToProgram(entities);
+            drawing.UpdateArea();
+            drawing.Color = PartColors[colorIndex % PartColors.Length];
+            colorIndex++;
+
+            var features = FeatureExtractor.Extract(drawing);
+            if (features == null)
+            {
+                Console.WriteLine(" - SKIP (feature extraction failed)");
+                skippedFeatures++;
+                continue;
+            }
+
+            Console.WriteLine($" (area={features.Area:F1}, verts={features.VertexCount})");
+
+            // Precompute best-fits once for all sheet sizes.
+            var sizes = sheetSuite.Select(sz => (sz.Width, sz.Length)).ToList();
+            var bfSw = Stopwatch.StartNew();
+            BestFitCache.ComputeForSizes(drawing, s, sizes);
+            bfSw.Stop();
+            Console.WriteLine($"  Best-fits computed in {bfSw.ElapsedMilliseconds}ms");
+
+            var partId = db.GetOrAddPart(Path.GetFileName(file), features, drawing.Program.ToString());
+            var partSw = Stopwatch.StartNew();
+            var runsThisPart = 0;
+            var bestUtil = 0.0;
+            var bestCount = 0;
+
+            foreach (var size in sheetSuite)
+            {
+                if (db.HasRun(Path.GetFileName(file), size.Width, size.Length, s))
+                {
+                    Console.WriteLine($"  {size.Length}x{size.Width} - skip (exists)");
+                    continue;
+                }
+
+                Plate runPlate;
+                if (templateNest != null)
+                {
+                    runPlate = templateNest.PlateDefaults.CreateNew();
+                    runPlate.Size = size;
+                    runPlate.PartSpacing = s;
+                }
+                else
+                {
+                    runPlate = new Plate { Size = size, PartSpacing = s };
+                }
+
+                var sizeSw = Stopwatch.StartNew();
+                var result = BruteForceRunner.Run(drawing, runPlate);
+                sizeSw.Stop();
+
+                if (result == null)
+                {
+                    Console.WriteLine($"  {size.Length}x{size.Width} - no fit");
+                    continue;
+                }
+
+                if (result.Utilization > bestUtil)
+                {
+                    bestUtil = result.Utilization;
+                    bestCount = result.PartCount;
+                }
+
+                Console.WriteLine($"  {size.Length}x{size.Width} - {result.PartCount}pcs, {result.Utilization:P1}, {sizeSw.ElapsedMilliseconds}ms");
+
+                string savedFilePath = null;
+                if (saveDir != null)
+                {
+                    // Deterministic bucket (00-FF) based on filename hash
+                    uint hash = 0;
+                    foreach (char c in partNo) hash = (hash * 31) + c;
+                    var bucket = (hash % 256).ToString("X2");
+
+                    var partDir = Path.Combine(saveDir, bucket, partNo);
+                    Directory.CreateDirectory(partDir);
+
+                    var nestName = $"{partNo}-{size.Length}x{size.Width}-{result.PartCount}pcs";
+                    var fileName = nestName + ".zip";
+                    savedFilePath = Path.Combine(partDir, fileName);
+
+                    // Create nest from template or from scratch
+                    Nest nestObj;
+                    if (templateNest != null)
+                    {
+                        nestObj = new Nest(nestName)
+                        {
+                            Units = templateNest.Units,
+                            DateCreated = DateTime.Now
+                        };
+                        nestObj.PlateDefaults.SetFromExisting(templateNest.PlateDefaults.CreateNew());
+                    }
+                    else
+                    {
+                        nestObj = new Nest(nestName) { Units = Units.Inches, DateCreated = DateTime.Now };
+                    }
+
+                    nestObj.Drawings.Add(drawing);
+                    var plateObj = nestObj.CreatePlate();
+                    plateObj.Size = size;
+                    plateObj.PartSpacing = s;
+                    plateObj.Parts.AddRange(result.PlacedParts);
+
+                    var writer = new NestWriter(nestObj);
+                    writer.Write(savedFilePath);
+                }
+
+                db.AddRun(partId, size.Width, size.Length, s, result, savedFilePath);
+                runsThisPart++;
+                totalRuns++;
+            }
+
+            BestFitCache.Invalidate(drawing);
+            partSw.Stop();
+            processed++;
+            Console.WriteLine($"  Total: {runsThisPart} runs, best={bestCount}pcs @ {bestUtil:P1}, {partSw.ElapsedMilliseconds}ms");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine();
+            Console.Error.WriteLine($"  ERROR: {ex.Message}");
+        }
+    }
+
+    totalSw.Stop();
+    Console.WriteLine("---");
+    Console.WriteLine($"Processed: {processed} parts, {totalRuns} total runs");
+    Console.WriteLine($"Skipped:   {skippedExisting} (existing) + {skippedGeometry} (no geometry) + {skippedFeatures} (no features)");
+    Console.WriteLine($"Time:      {totalSw.Elapsed:h\\:mm\\:ss}");
+    Console.WriteLine($"Database:  {Path.GetFullPath(resolvedDb)}");
+    return 0;
+}
+
+void PrintUsage()
+{
+    Console.Error.WriteLine("Usage: OpenNest.Training <dxf-dir> [options]");
+    Console.Error.WriteLine();
+    Console.Error.WriteLine("Arguments:");
+    Console.Error.WriteLine("  dxf-dir                Directory containing DXF files to process");
+    Console.Error.WriteLine();
+    Console.Error.WriteLine("Options:");
+    Console.Error.WriteLine("  --spacing <value>      Part spacing (default: 0.5)");
+    Console.Error.WriteLine("  --db <path>            SQLite database path (default: OpenNestTraining.db)");
+    Console.Error.WriteLine("  --save-nests <dir>     Directory to save individual .zip nests for each winner");
+    Console.Error.WriteLine("  --template <path>      Nest template (.nstdot) for plate defaults");
+    Console.Error.WriteLine("  -h, --help             Show this help");
+}

OpenNest.Training/TrainingDatabase.cs

@@ -0,0 +1,131 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Microsoft.EntityFrameworkCore;
+using OpenNest.Engine.ML;
+using OpenNest.IO;
+using OpenNest.Training.Data;
+
+namespace OpenNest.Training
+{
+    public class TrainingDatabase : IDisposable
+    {
+        private readonly TrainingDbContext _db;
+
+        public TrainingDatabase(string dbPath)
+        {
+            if (!dbPath.EndsWith(".db", StringComparison.OrdinalIgnoreCase))
+                dbPath += ".db";
+
+            _db = new TrainingDbContext(dbPath);
+            _db.Database.EnsureCreated();
+        }
+
+        public long GetOrAddPart(string fileName, PartFeatures features, string geometryData)
+        {
+            var existing = _db.Parts.FirstOrDefault(p => p.FileName == fileName);
+            if (existing != null) return existing.Id;
+
+            var part = new TrainingPart
+            {
+                FileName = fileName,
+                Area = features.Area,
+                Convexity = features.Convexity,
+                AspectRatio = features.AspectRatio,
+                BBFill = features.BoundingBoxFill,
+                Circularity = features.Circularity,
+                PerimeterToAreaRatio = features.PerimeterToAreaRatio,
+                VertexCount = features.VertexCount,
+                Bitmask = features.Bitmask,
+                GeometryData = geometryData
+            };
+
+            _db.Parts.Add(part);
+            _db.SaveChanges();
+            return part.Id;
+        }
+
+        public bool HasRun(string fileName, double sheetWidth, double sheetHeight, double spacing)
+        {
+            return _db.Runs.Any(r =>
+                r.Part.FileName == fileName &&
+                r.SheetWidth == sheetWidth &&
+                r.SheetHeight == sheetHeight &&
+                r.Spacing == spacing);
+        }
+
+        public int RunCount(string fileName)
+        {
+            return _db.Runs.Count(r => r.Part.FileName == fileName);
+        }
+
+        public void AddRun(long partId, double w, double h, double s, BruteForceResult result, string filePath)
+        {
+            var run = new TrainingRun
+            {
+                PartId = partId,
+                SheetWidth = w,
+                SheetHeight = h,
+                Spacing = s,
+                PartCount = result.PartCount,
+                Utilization = result.Utilization,
+                TimeMs = result.TimeMs,
+                LayoutData = result.LayoutData ?? "",
+                FilePath = filePath ?? ""
+            };
+
+            _db.Runs.Add(run);
+            _db.SaveChanges();
+        }
+
+        public int BackfillPerimeterToAreaRatio()
+        {
+            var partsToFix = _db.Parts
+                .Where(p => p.PerimeterToAreaRatio == 0)
+                .Select(p => new { p.Id, p.GeometryData })
+                .ToList();
+
+            if (partsToFix.Count == 0) return 0;
+
+            var updated = 0;
+            foreach (var item in partsToFix)
+            {
+                try
+                {
+                    var stream = new MemoryStream(Encoding.UTF8.GetBytes(item.GeometryData));
+                    var programReader = new ProgramReader(stream);
+                    var program = programReader.Read();
+
+                    var drawing = new Drawing("backfill") { Program = program };
+                    drawing.UpdateArea();
+
+                    var features = FeatureExtractor.Extract(drawing);
+                    if (features == null) continue;
+
+                    var part = _db.Parts.Find(item.Id);
+                    part.PerimeterToAreaRatio = features.PerimeterToAreaRatio;
+                    _db.SaveChanges();
+                    updated++;
+                }
+                catch
+                {
+                    // Skip parts that fail to reconstruct.
+                }
+            }
+
+            return updated;
+        }
+
+        public void SaveChanges()
+        {
+            _db.SaveChanges();
+        }
+
+        public void Dispose()
+        {
+            _db?.Dispose();
+        }
+    }
+}

OpenNest.sln

@@ -17,6 +17,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OpenNest.Mcp", "OpenNest.Mc
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OpenNest.Console", "OpenNest.Console\OpenNest.Console.csproj", "{58E00A25-86B5-42C7-87B5-DE4AD22381EA}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OpenNest.Training", "OpenNest.Training\OpenNest.Training.csproj", "{249BF728-25DD-4863-8266-207ACD26E964}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -111,6 +113,18 @@ Global
 		{58E00A25-86B5-42C7-87B5-DE4AD22381EA}.Release|x64.Build.0 = Release|Any CPU
 		{58E00A25-86B5-42C7-87B5-DE4AD22381EA}.Release|x86.ActiveCfg = Release|Any CPU
 		{58E00A25-86B5-42C7-87B5-DE4AD22381EA}.Release|x86.Build.0 = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|x64.Build.0 = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Debug|x86.Build.0 = Debug|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|Any CPU.Build.0 = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|x64.ActiveCfg = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|x64.Build.0 = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|x86.ActiveCfg = Release|Any CPU
+		{249BF728-25DD-4863-8266-207ACD26E964}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE