diff --git a/src/commandlets/lightmapcmd.cpp b/src/commandlets/lightmapcmd.cpp
index 4cc9d4483..031eff9b0 100644
--- a/src/commandlets/lightmapcmd.cpp
+++ b/src/commandlets/lightmapcmd.cpp
@@ -2,6 +2,7 @@
 #include "lightmapcmd.h"
 #include "g_levellocals.h"
 #include "d_event.h"
+#include "v_video.h"
 
 void G_SetMap(const char* mapname, int mode);
 void D_SingleTick();
@@ -41,8 +42,56 @@ void LightmapBuildCmdlet::OnCommand(FArgs args)
 				break;
 		}
 
-		Printf("Baking LIGHTMAP lump!\n");
-		Printf("Current map is %s", level.LevelName.GetChars());
+		if (!level.levelMesh)
+		{
+			Printf("No level mesh. Perhaps your level has no lightmap loaded?\n");
+			return;
+		}
+
+		if (!level.lightmaps)
+		{
+			Printf("Lightmap is not enabled in this level.\n");
+		}
+
+		Printf("Baking lightmaps. Please wait...\n");
+
+		uint32_t atlasPixelCount = level.levelMesh->AtlasPixelCount();
+		auto stats = level.levelMesh->GatherTilePixelStats();
+
+		Printf("Surfaces: %u (awaiting updates: %u static, %u dynamic)\n", stats.tiles.total, stats.tiles.dirty, stats.tiles.dirtyDynamic);
+		Printf("Surface pixel area to update: %u static, %u dynamic\n", stats.pixels.dirty, stats.pixels.dirtyDynamic);
+		Printf("Surface pixel area: %u\nAtlas pixel area: %u\n", stats.pixels.total, atlasPixelCount);
+		Printf("Atlas efficiency: %.4f%%\n", float(stats.pixels.total) / float(atlasPixelCount) * 100.0f);
+
+		Printf("Baking lightmap. Please wait...\n");
+
+		TArray<LightmapTile*> tiles;
+
+		while (stats.tiles.dirty > 0)
+		{
+			tiles.Clear();
+			for (auto& e : level.levelMesh->Lightmap.Tiles)
+			{
+				if (e.NeedsUpdate && e.AlwaysUpdate == 0)
+				{
+					tiles.Push(&e);
+					if (tiles.Size() == 1001)
+						break;
+				}
+			}
+
+			if (tiles.Size() == 0)
+				break;
+
+			screen->BeginFrame();
+			screen->UpdateLightmaps(tiles);
+			screen->Update();
+		}
+
+		Printf("Finished baking map.\n");
+		level.levelMesh->SaveLightmapLump(level);
+
+		Printf("Lightmap build complete.\n");
 	});
 }