diff --git a/OmeSliCC/ImageGenerator.py b/OmeSliCC/ImageGenerator.py
index 78cc7c8..9e25532 100644
--- a/OmeSliCC/ImageGenerator.py
+++ b/OmeSliCC/ImageGenerator.py
@@ -108,6 +108,9 @@ def __init__(self, size, tile_size, dtype=np.uint8, seed=None):
         self.tile_size = tile_size
         self.dtype = dtype
 
+        ranges = np.flip(np.ceil(np.divide(self.size, self.tile_size)).astype(int))
+        self.tile_indices = list(np.ndindex(tuple(ranges)))
+
         if seed is not None:
             np.random.seed(seed)
 
@@ -133,9 +136,8 @@ def get_tiles(self):
             max_val = 2 ** (8 * np.dtype(dtype).itemsize) - 1
         else:
             max_val = 1
-        ranges = np.flip(np.ceil(np.divide(self.size, self.tile_size)).astype(int))
         # flip: cycle over indices in x, y, z order using range = [z, y, x]
-        for indices in tqdm(list(np.ndindex(tuple(ranges)))):
+        for indices in tqdm(self.tile_indices):
             self.range0 = np.flip(indices) * tile_size
             self.range1 = np.min([self.range0 + self.tile_size, self.size], 0)
             shape = list(reversed(self.range1 - self.range0))
@@ -165,23 +167,35 @@ def save_tiff(filename, data, shape=None, dtype=None, tile_size=None, bigtiff=No
                      compression=compression)
 
 
-def render_image(data, shape, dtype):
-    #for slice1, tile in tqdm(data):
-    #    image[slice1] = tile
-
-    image = np.zeros(shape, dtype=dtype)
-    position = np.array([0] * len(shape))
-    for tile in data:
-        image[position: position + tile.shape] = tile
-        position += tile.shape
-        # TODO: increase/carry-over (x,) y, z
-    image = image.reshape(shape)
+def render_image(image_generator):
+    data = image_generator.get_tiles()
+    dtype = image_generator.dtype
+    tile_indices = image_generator.tile_indices
+    shape = np.flip(image_generator.size)
+    multi_dimensional = (len(shape) > 2)
 
-    if len(shape) <= 3 and shape[-1] <= 4:
-        show_image(image)
+    if multi_dimensional:
+        shape1 = list(shape)[1:] + [3]
     else:
-        i = shape[3] // 2 + 2
-        show_image(image[:, :, i, :])
+        shape1 = list(shape) + [3]
+    image = np.zeros(shape1, dtype=dtype)
+    first = True
+    for indices, tile in zip(tile_indices, data):
+        tile_shape = tile.shape[:-1]
+        range0 = np.multiply(indices, tile_shape)
+        range1 = np.min([range0 + tile_shape, shape], 0)
+
+        # break after first z
+        if not first and np.all(range0[-2:] == [0, 0]):
+            break
+
+        if multi_dimensional:
+            image[range0[1]: range1[1], range0[2]: range1[2], :] = tile[0, ...]
+        else:
+            image[range0[0]: range1[0], range0[1]: range1[1], :] = tile
+        first = False
+
+    show_image(image)
 
 
 def show_image(image):
@@ -210,5 +224,4 @@ def show_image(image):
     save_tiff(path, data, shape, dtype, tile_size=tile_shape, ome=True)
     print('save done')
 
-    data = image_generator.get_tiles()
-    render_image(data, shape, dtype)
+    render_image(image_generator)