add multiple mesh support

src/GPUTileHandler.cs

@@ -5,6 +5,7 @@
 using SharpGLTF.Schema2;
 using SharpGLTF.Schema2.Tiles3D;
 using SharpGLTF.Transforms;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;
@@ -87,13 +88,17 @@ private static void AddModelInstancesToScene(SceneBuilder sceneBuilder, IEnumera
     {
         var modelInstances = instances.Where(s => s.Model.Equals(model)).ToList();
         var modelRoot = ModelRoot.Load(model);
-        var meshBuilder = modelRoot.LogicalMeshes.First().ToMeshBuilder(); // todo: what if there are multiple meshes?
+
         var pointId = 0;
 
         foreach (var instance in modelInstances)
         {
-            var sceneBuilderModel = GetSceneBuilder(meshBuilder, instance, UseScaleNonUniform, translation, pointId);
-            sceneBuilder.AddScene(sceneBuilderModel, Matrix4x4.Identity);
+            foreach(var mesh in modelRoot.LogicalMeshes)
+            {
+                var meshBuilder = mesh.ToMeshBuilder(); // todo: what if there are multiple meshes?
+                var sceneBuilderModel = GetSceneBuilder(meshBuilder, instance, UseScaleNonUniform, translation, pointId);
+                sceneBuilder.AddScene(sceneBuilderModel, Matrix4x4.Identity);
+            }
             pointId++;
         }
     }

src/ImplicitTiling.cs

@@ -2,6 +2,7 @@
 using subtree;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using Wkx;
@@ -95,8 +96,7 @@ private static byte[] CreateTile(Options o, NpgsqlConnection conn, BoundingBox t
 
         if (useGpuInstancing)
         {
-
-           tile = GPUTileHandler.GetGPUTile(instances, (bool)o.UseScaleNonUniform);
+            tile = GPUTileHandler.GetGPUTile(instances, (bool)o.UseScaleNonUniform);
         }
         else if(!useI3dm)
         {

src/Program.cs

@@ -66,7 +66,6 @@ static void Main(string[] args)
             {
                 Console.WriteLine($"Query: {o.Query}");
             }
-
             var bbox = InstancesRepository.GetBoundingBoxForTable(conn, o.Table, geom_column, heights, o.Query);
 
             var bbox_wgs84 = bbox.bbox;