diff --git a/src/main/java/ca/blarg/gdx/tilemap3d/json/tilemap/TileMapJsonLoader.java b/src/main/java/ca/blarg/gdx/tilemap3d/json/tilemap/TileMapJsonLoader.java
index ec23623..1a731ee 100644
--- a/src/main/java/ca/blarg/gdx/tilemap3d/json/tilemap/TileMapJsonLoader.java
+++ b/src/main/java/ca/blarg/gdx/tilemap3d/json/tilemap/TileMapJsonLoader.java
@@ -4,62 +4,62 @@ import ca.blarg.gdx.Strings;
 import ca.blarg.gdx.tilemap3d.ChunkVertexGenerator;
 import ca.blarg.gdx.tilemap3d.TileChunk;
 import ca.blarg.gdx.tilemap3d.TileMap;
-import ca.blarg.gdx.tilemap3d.json.tilemap.JsonTileMap;
-import ca.blarg.gdx.tilemap3d.json.tilemap.TileDataSerializer;
+import ca.blarg.gdx.tilemap3d.lighting.LightSpreadingTileMapLighter;
+import ca.blarg.gdx.tilemap3d.lighting.LitChunkVertexGenerator;
+import ca.blarg.gdx.tilemap3d.lighting.SimpleTileMapLighter;
 import ca.blarg.gdx.tilemap3d.lighting.TileMapLighter;
 import ca.blarg.gdx.tilemap3d.tilemesh.TileMeshCollection;
 import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.assets.AssetManager;
 import com.badlogic.gdx.files.FileHandle;
 import com.badlogic.gdx.utils.Base64Coder;
 import com.badlogic.gdx.utils.Json;
-import sun.reflect.generics.reflectiveObjects.NotImplementedException;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 
 public class TileMapJsonLoader {
-	public static TileMap load(String mapFile, TileMeshCollection tileMeshes) {
-		return load(Gdx.files.internal(mapFile), tileMeshes);
+	public static JsonTileMap load(FileHandle file) {
+		Json json = new Json();
+		return json.fromJson(JsonTileMap.class, file);
 	}
 
-	public static TileMap load(FileHandle mapFile, TileMeshCollection tileMeshes) {
-		if (mapFile == null)
-			throw new IllegalArgumentException();
-		if (tileMeshes == null)
-			throw new IllegalArgumentException();
-
-		Json json = new Json();
-		JsonTileMap jsonMap = json.fromJson(JsonTileMap.class, mapFile);
-
-		if (jsonMap.chunks == null || jsonMap.chunks.size() == 0)
+	public static TileMap create(JsonTileMap definition, AssetManager assetManager) {
+		if (definition.chunks == null || definition.chunks.size() == 0)
 			throw new RuntimeException("Invalid map: no chunks.");
-		int numChunks = (jsonMap.widthInChunks * jsonMap.heightInChunks * jsonMap.depthInChunks);
-		if (jsonMap.chunks.size() != numChunks)
+		int numChunks = (definition.widthInChunks * definition.heightInChunks * definition.depthInChunks);
+		if (definition.chunks.size() != numChunks)
 			throw new RuntimeException("Inconsistent map dimensions and number of chunks.");
+		if (definition.tileMeshes == null)
+			throw new RuntimeException("No tile mesh collection specified.");
+
+		TileMeshCollection tileMeshes = assetManager.get(definition.tileMeshes, TileMeshCollection.class);
 
 		ChunkVertexGenerator chunkVertexGenerator = null;
 		TileMapLighter lighter = null;
 
-		if (Strings.isNullOrEmpty(jsonMap.lightingMode)) {
+		if (Strings.isNullOrEmpty(definition.lightingMode)) {
 			chunkVertexGenerator = new ChunkVertexGenerator();
 			lighter = null;
-		} else if (jsonMap.lightingMode.equalsIgnoreCase("simple")) {
-			throw new NotImplementedException();
-		} else if (jsonMap.lightingMode.equalsIgnoreCase("skyAndSources")) {
-			throw new NotImplementedException();
+		} else if (definition.lightingMode.equalsIgnoreCase("simple")) {
+			chunkVertexGenerator = new LitChunkVertexGenerator();
+			lighter = new SimpleTileMapLighter();
+		} else if (definition.lightingMode.equalsIgnoreCase("skyAndSources")) {
+			chunkVertexGenerator = new LitChunkVertexGenerator();
+			lighter = new LightSpreadingTileMapLighter(true, true);
 		} else
 			throw new RuntimeException("Invalid lighting mode.");
 
 		TileMap tileMap = new TileMap(
-				jsonMap.chunkWidth, jsonMap.chunkHeight, jsonMap.chunkDepth,
-				jsonMap.widthInChunks, jsonMap.heightInChunks, jsonMap.depthInChunks,
-				tileMeshes,
-				chunkVertexGenerator,
-				lighter
+			definition.chunkWidth, definition.chunkHeight, definition.chunkDepth,
+			definition.widthInChunks, definition.heightInChunks, definition.depthInChunks,
+			tileMeshes,
+			chunkVertexGenerator,
+			lighter
 		);
 
-		for (int i = 0; i < jsonMap.chunks.size(); ++i) {
-			String encodedChunk = jsonMap.chunks.get(i);
+		for (int i = 0; i < definition.chunks.size(); ++i) {
+			String encodedChunk = definition.chunks.get(i);
 			TileChunk outputChunk = tileMap.getChunks()[i];
 
 			byte[] chunkBytes = Base64Coder.decode(encodedChunk);
@@ -83,8 +83,12 @@ public class TileMapJsonLoader {
 		jsonMap.heightInChunks = tileMap.getHeight() / jsonMap.chunkHeight;
 		jsonMap.depthInChunks = tileMap.getDepth() / jsonMap.chunkDepth;
 
-		// TODO: figure out real lighting mode from the types of vertex generator / lighter objects set
-		jsonMap.lightingMode = null;
+		if (tileMap.lighter == null)
+			jsonMap.lightingMode = null;
+		else if (tileMap.lighter instanceof SimpleTileMapLighter)
+			jsonMap.lightingMode = "simple";
+		else if (tileMap.lighter instanceof LightSpreadingTileMapLighter)
+			jsonMap.lightingMode = "skyAndSources";
 
 		// each serialized chunk will be the same size in bytes (same number of tiles in each)
 		int chunkSizeInBytes = tileMap.getChunks()[0].getData().length * TileDataSerializer.TILE_SIZE_BYTES;