public async Task Convert(MapDocument document, SceneBuilder builder, IEnumerable <IMapObject> affected, ResourceCollector resourceCollector)
        {
            var objs = document.Map.Root.FindAll();

            if (affected != null)
            {
                var groups = affected.Select(x => x.ID / 200).ToHashSet();
                foreach (var g in groups)
                {
                    resourceCollector.RemoveRenderables(builder.GetRenderablesForGroup(g));
                    builder.DeleteGroup(g);
                }
                objs = objs.Where(x => groups.Contains(x.ID / 200)).ToList();
            }

            var converters      = _converters.Select(x => x.Value).OrderBy(x => (int)x.Priority).ToList();
            var groupConverters = _groupConverters.Select(x => x.Value).OrderBy(x => (int)x.Priority).ToList();

            foreach (var g in objs.GroupBy(x => x.ID / 200))
            {
                builder.EnsureGroupExists(g.Key);
                var buffer    = builder.GetBufferForGroup(g.Key);
                var collector = new ResourceCollector();

                foreach (var gc in groupConverters)
                {
                    gc.Convert(buffer, document, g, collector);
                }

                foreach (var obj in g)
                {
                    foreach (var converter in converters)
                    {
                        if (!converter.Supports(obj))
                        {
                            continue;
                        }
                        await converter.Convert(buffer, document, obj, collector);

                        if (converter.ShouldStopProcessing(document, obj))
                        {
                            break;
                        }
                    }
                }

                builder.RemoveRenderablesFromGroup(g.Key, collector.GetRenderablesToRemove());
                builder.AddRenderablesToGroup(g.Key, collector.GetRenderablesToAdd());

                resourceCollector.Merge(collector);
            }

            builder.Complete();
        }