io_scene_fbx/import_fbx.py

@@ -785,87 +785,258 @@ def blen_read_geom_layerinfo(fbx_layer):
         )
 
 
-def blen_read_geom_array_setattr(generator, blen_data, blen_attr, fbx_data, stride, item_size, descr, xform):
-    """Generic fbx_layer to blen_data setter, generator is expected to yield tuples (ble_idx, fbx_idx)."""
-    max_blen_idx = len(blen_data) - 1
-    max_fbx_idx = len(fbx_data) - 1
-    print_error = True
+def blen_read_geom_validate_blen_data(blen_data, blen_dtype, item_size):
+    """Validate blen_data when it's not a bpy_prop_collection.
+    Returns whether blen_data is a bpy_prop_collection"""
+    blen_data_is_collection = isinstance(blen_data, bpy.types.bpy_prop_collection)
+    if not blen_data_is_collection:
+        if item_size > 1:
+            assert(len(blen_data.shape) == 2)
+            assert(blen_data.shape[1] == item_size)
+        assert(blen_data.dtype == blen_dtype)
+    return blen_data_is_collection
 
-    def check_skip(blen_idx, fbx_idx):
-        nonlocal print_error
-        if fbx_idx < 0:  # Negative values mean 'skip'.
-            return True
-        if blen_idx > max_blen_idx:
-            if print_error:
-                print("ERROR: too much data in this Blender layer, compared to elements in mesh, skipping!")
-                print_error = False
-            return True
-        if fbx_idx + item_size - 1 > max_fbx_idx:
-            if print_error:
-                print("ERROR: not enough data in this FBX layer, skipping!")
-                print_error = False
-            return True
-        return False
 
-    if xform is not None:
-        if isinstance(blen_data, list):
-            if item_size == 1:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    blen_data[blen_idx] = xform(fbx_data[fbx_idx])
-            else:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    blen_data[blen_idx] = xform(fbx_data[fbx_idx:fbx_idx + item_size])
-        else:
-            if item_size == 1:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    setattr(blen_data[blen_idx], blen_attr, xform(fbx_data[fbx_idx]))
-            else:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    setattr(blen_data[blen_idx], blen_attr, xform(fbx_data[fbx_idx:fbx_idx + item_size]))
+def blen_read_geom_parse_fbx_data(fbx_data, stride, item_size):
+    """Parse fbx_data as an array.array into a 2d np.ndarray that shares the same memory, where each row is a single
+    item"""
+    # Technically stride < item_size could be supported, but there's probably not a use case for it since it would
+    # result in a view of the data with self-overlapping memory.
+    assert(stride >= item_size)
+    # View the array.array as an np.ndarray.
+    fbx_data_np = parray_as_ndarray(fbx_data)
+
+    if stride == item_size:
+        if item_size > 1:
+            # Need to make sure fbx_data_np has a whole number of items to be able to view item_size elements per row.
+            items_remainder = len(fbx_data_np) % item_size
+            if items_remainder:
+                print("ERROR: not a whole number of items in this FBX layer, skipping the partial item!")
+                fbx_data_np = fbx_data_np[:-items_remainder]
+        fbx_data_np = fbx_data_np.reshape(-1, item_size)
     else:
-        if isinstance(blen_data, list):
-            if item_size == 1:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    blen_data[blen_idx] = fbx_data[fbx_idx]
+        # Create a view of fbx_data_np that is only the first item_size elements of each stride. Note that the view will
+        # not be C-contiguous.
+        stride_remainder = len(fbx_data_np) % stride
+        if stride_remainder:
+            if stride_remainder < item_size:
+                print("ERROR: not a whole number of items in this FBX layer, skipping the partial item!")
+                # Not enough in the remainder for a full item, so cut off the partial stride
+                fbx_data_np = fbx_data_np[:-stride_remainder]
+                # Reshape to one stride per row and then create a view that includes only the first item_size elements
+                # of each stride.
+                fbx_data_np = fbx_data_np.reshape(-1, stride)[:, :item_size]
             else:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    blen_data[blen_idx] = fbx_data[fbx_idx:fbx_idx + item_size]
+                print("ERROR: not a whole number of strides in this FBX layer! There are a whole number of items, but"
+                      " this could indicate an error!")
+                # There is not a whole number of strides, but there is a whole number of items.
+                # This is a pain to deal with because fbx_data_np.reshape(-1, stride) is not possible.
+                # A view of just the items can be created using stride_tricks.as_strided by specifying the shape and
+                # strides of the view manually.
+                # Extreme care must be taken when using stride_tricks.as_strided because improper usage can result in
+                # a view that gives access to memory outside the array.
+                from numpy.lib import stride_tricks
+
+                # fbx_data_np should always start off as flat and C-contiguous.
+                assert(fbx_data_np.strides == (fbx_data_np.itemsize,))
+
+                num_whole_strides = len(fbx_data_np) // stride
+                # Plus the one partial stride that is enough elements for a complete item.
+                num_items = num_whole_strides + 1
+                shape = (num_items, item_size)
+
+                # strides are the number of bytes to step to get to the next element, for each axis.
+                step_per_item = fbx_data_np.itemsize * stride
+                step_per_item_element = fbx_data_np.itemsize
+                strides = (step_per_item, step_per_item_element)
+
+                fbx_data_np = stride_tricks.as_strided(fbx_data_np, shape, strides)
         else:
-            if item_size == 1:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    setattr(blen_data[blen_idx], blen_attr, fbx_data[fbx_idx])
-            else:
-                def _process(blend_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx):
-                    setattr(blen_data[blen_idx], blen_attr, fbx_data[fbx_idx:fbx_idx + item_size])
+            # There's a whole number of strides, so first reshape to one stride per row and then create a view that
+            # includes only the first item_size elements of each stride.
+            fbx_data_np = fbx_data_np.reshape(-1, stride)[:, :item_size]
 
-    for blen_idx, fbx_idx in generator:
-        if check_skip(blen_idx, fbx_idx):
-            continue
-        _process(blen_data, blen_attr, fbx_data, xform, item_size, blen_idx, fbx_idx)
+    return fbx_data_np
 
 
-# generic generators.
-def blen_read_geom_array_gen_allsame(data_len):
-    return zip(*(range(data_len), (0,) * data_len))
+def blen_read_geom_check_fbx_data_length(blen_data, fbx_data_np, is_indices=False):
+    """Check that there are the same number of items in blen_data and fbx_data_np.
+
+    Returns a tuple of two elements:
+        0: fbx_data_np or, if fbx_data_np contains more items than blen_data, a view of fbx_data_np with the excess
+           items removed
+        1: Whether the returned fbx_data_np contains enough items to completely fill blen_data"""
+    bl_num_items = len(blen_data)
+    fbx_num_items = len(fbx_data_np)
+    enough_data = fbx_num_items >= bl_num_items
+    if not enough_data:
+        if is_indices:
+            print("ERROR: not enough indices in this FBX layer, missing data will be left as default!")
+        else:
+            print("ERROR: not enough data in this FBX layer, missing data will be left as default!")
+    elif fbx_num_items > bl_num_items:
+        if is_indices:
+            print("ERROR: too many indices in this FBX layer, skipping excess!")
+        else:
+            print("ERROR: too much data in this FBX layer, skipping excess!")
+        fbx_data_np = fbx_data_np[:bl_num_items]
+
+    return fbx_data_np, enough_data
 
 
-def blen_read_geom_array_gen_direct(fbx_data, stride):
-    fbx_data_len = len(fbx_data)
-    return zip(*(range(fbx_data_len // stride), range(0, fbx_data_len, stride)))
+def blen_read_geom_xform(fbx_data_np, xform):
+    """xform is either None, or a function that takes fbx_data_np as its only positional argument and returns an
+    np.ndarray with the same total number of elements as fbx_data_np.
+    It is acceptable for xform to return an array with a different dtype to fbx_data_np.
+
+    Returns xform(fbx_data_np) when xform is not None and ensures the result of xform(fbx_data_np) has the same shape as
+    fbx_data_np before returning it.
+    When xform is None, fbx_data_np is returned as is."""
+    if xform is not None:
+        item_size = fbx_data_np.shape[1]
+        fbx_total_data = fbx_data_np.size
+        fbx_data_np = xform(fbx_data_np)
+        # The amount of data should not be changed by xform
+        assert(fbx_data_np.size == fbx_total_data)
+        # Ensure fbx_data_np is still item_size elements per row
+        if len(fbx_data_np.shape) != 2 or fbx_data_np.shape[1] != item_size:
+            fbx_data_np = fbx_data_np.reshape(-1, item_size)
+    return fbx_data_np
 
 
-def blen_read_geom_array_gen_indextodirect(fbx_layer_index, stride):
-    return ((bi, fi * stride) for bi, fi in enumerate(fbx_layer_index))
+def blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_data, stride, item_size, descr,
+                                            xform):
+    """Generic fbx_layer to blen_data foreach setter for Direct layers.
+    blen_data must be a bpy_prop_collection or 2d np.ndarray whose second axis length is item_size.
+    fbx_data must be an array.array."""
+    fbx_data_np = blen_read_geom_parse_fbx_data(fbx_data, stride, item_size)
+    fbx_data_np, enough_data = blen_read_geom_check_fbx_data_length(blen_data, fbx_data_np)
+    fbx_data_np = blen_read_geom_xform(fbx_data_np, xform)
+
+    blen_data_is_collection = blen_read_geom_validate_blen_data(blen_data, blen_dtype, item_size)
+
+    if blen_data_is_collection:
+        if not enough_data:
+            blen_total_data = len(blen_data) * item_size
+            buffer = np.empty(blen_total_data, dtype=blen_dtype)
+            # It's not clear what values should be used for the missing data, so read the current values into a buffer.
+            blen_data.foreach_get(blen_attr, buffer)
+
+            # Change the buffer shape to one item per row
+            buffer.shape = (-1, item_size)
+
+            # Copy the fbx data into the start of the buffer
+            buffer[:len(fbx_data_np)] = fbx_data_np
+        else:
+            # Convert the buffer to the Blender C type of blen_attr
+            buffer = astype_view_signedness(fbx_data_np, blen_dtype)
+
+        # Set blen_attr of blen_data. The buffer must be flat and C-contiguous, which ravel() ensures
+        blen_data.foreach_set(blen_attr, buffer.ravel())
+    else:
+        assert(blen_data.size % item_size == 0)
+        blen_data = blen_data.view()
+        blen_data.shape = (-1, item_size)
+        blen_data[:len(fbx_data_np)] = fbx_data_np
 
 
-def blen_read_geom_array_gen_direct_looptovert(mesh, fbx_data, stride):
-    fbx_data_len = len(fbx_data) // stride
-    loops = mesh.loops
-    for p in mesh.polygons:
-        for lidx in p.loop_indices:
-            vidx = loops[lidx].vertex_index
-            if vidx < fbx_data_len:
-                yield lidx, vidx * stride
+def blen_read_geom_array_foreach_set_indexed(blen_data, blen_attr, blen_dtype, fbx_data, fbx_layer_index, stride,
+                                             item_size, descr, xform):
+    """Generic fbx_layer to blen_data foreach setter for IndexToDirect layers.
+    blen_data must be a bpy_prop_collection or 2d np.ndarray whose second axis length is item_size.
+    fbx_data must be an array.array or a 1d np.ndarray."""
+    fbx_data_np = blen_read_geom_parse_fbx_data(fbx_data, stride, item_size)
+    fbx_data_np = blen_read_geom_xform(fbx_data_np, xform)
+
+    # fbx_layer_index is allowed to be a 1d np.ndarray for use with blen_read_geom_array_foreach_set_looptovert.
+    if not isinstance(fbx_layer_index, np.ndarray):
+        fbx_layer_index = parray_as_ndarray(fbx_layer_index)
+
+    fbx_layer_index, enough_indices = blen_read_geom_check_fbx_data_length(blen_data, fbx_layer_index, is_indices=True)
+
+    blen_data_is_collection = blen_read_geom_validate_blen_data(blen_data, blen_dtype, item_size)
+
+    blen_data_items_len = len(blen_data)
+    blen_data_len = blen_data_items_len * item_size
+    fbx_num_items = len(fbx_data_np)
+
+    # Find all indices that are out of bounds of fbx_data_np.
+    min_index_inclusive = -fbx_num_items
+    max_index_inclusive = fbx_num_items - 1
+    valid_index_mask = np.equal(fbx_layer_index, fbx_layer_index.clip(min_index_inclusive, max_index_inclusive))
+    indices_invalid = not valid_index_mask.all()
+
+    fbx_data_items = fbx_data_np.reshape(-1, item_size)
+
+    if indices_invalid or not enough_indices:
+        if blen_data_is_collection:
+            buffer = np.empty(blen_data_len, dtype=blen_dtype)
+            buffer_item_view = buffer.view()
+            buffer_item_view.shape = (-1, item_size)
+            # Since we don't know what the default values should be for the missing data, read the current values into a
+            # buffer.
+            blen_data.foreach_get(blen_attr, buffer)
+        else:
+            buffer_item_view = blen_data
+
+        if not enough_indices:
+            # Reduce the length of the view to the same length as the number of indices.
+            buffer_item_view = buffer_item_view[:len(fbx_layer_index)]
+
+        # Copy the result of indexing fbx_data_items by each element in fbx_layer_index into the buffer.
+        if indices_invalid:
+            print("ERROR: indices in this FBX layer out of bounds of the FBX data, skipping invalid indices!")
+            buffer_item_view[valid_index_mask] = fbx_data_items[fbx_layer_index[valid_index_mask]]
+        else:
+            buffer_item_view[:] = fbx_data_items[fbx_layer_index]
+
+        if blen_data_is_collection:
+            blen_data.foreach_set(blen_attr, buffer.ravel())
+    else:
+        if blen_data_is_collection:
+            # Cast the buffer to the Blender C type of blen_attr
+            fbx_data_items = astype_view_signedness(fbx_data_items, blen_dtype)
+            buffer_items = fbx_data_items[fbx_layer_index]
+            blen_data.foreach_set(blen_attr, buffer_items.ravel())
+        else:
+            blen_data[:] = fbx_data_items[fbx_layer_index]
+
+
+def blen_read_geom_array_foreach_set_allsame(blen_data, blen_attr, blen_dtype, fbx_data, stride, item_size, descr,
+                                             xform):
+    """Generic fbx_layer to blen_data foreach setter for AllSame layers.
+    blen_data must be a bpy_prop_collection or 2d np.ndarray whose second axis length is item_size.
+    fbx_data must be an array.array."""
+    fbx_data_np = blen_read_geom_parse_fbx_data(fbx_data, stride, item_size)
+    fbx_data_np = blen_read_geom_xform(fbx_data_np, xform)
+    blen_data_is_collection = blen_read_geom_validate_blen_data(blen_data, blen_dtype, item_size)
+    fbx_items_len = len(fbx_data_np)
+    blen_items_len = len(blen_data)
+
+    if fbx_items_len < 1:
+        print("ERROR: not enough data in this FBX layer, skipping!")
+        return
+
+    if blen_data_is_collection:
+        # Create an array filled with the value from fbx_data_np
+        buffer = np.full((blen_items_len, item_size), fbx_data_np[0], dtype=blen_dtype)
+
+        blen_data.foreach_set(blen_attr, buffer.ravel())
+    else:
+        blen_data[:] = fbx_data_np[0]
+
+
+def blen_read_geom_array_foreach_set_looptovert(mesh, blen_data, blen_attr, blen_dtype, fbx_data, stride, item_size,
+                                                descr, xform):
+    """Generic fbx_layer to blen_data foreach setter for polyloop ByVertice layers.
+    blen_data must be a bpy_prop_collection or 2d np.ndarray whose second axis length is item_size.
+    fbx_data must be an array.array"""
+    # The fbx_data is mapped to vertices. To expand fbx_data to polygon loops, get an array of the vertex index of each
+    # polygon loop that will then be used to index fbx_data
+    loop_vertex_indices = np.empty(len(mesh.loops), dtype=np.uintc)
+    mesh.loops.foreach_get("vertex_index", loop_vertex_indices)
+    blen_read_geom_array_foreach_set_indexed(blen_data, blen_attr, blen_dtype, fbx_data, loop_vertex_indices, stride,
+                                             item_size, descr, xform)
 
 
 # generic error printers.
@@ -880,7 +1051,7 @@ def blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet=False):
 
 
 def blen_read_geom_array_mapped_vert(
-        mesh, blen_data, blen_attr,
+        mesh, blen_data, blen_attr, blen_dtype,
         fbx_layer_data, fbx_layer_index,
         fbx_layer_mapping, fbx_layer_ref,
         stride, item_size, descr,
@@ -889,15 +1060,15 @@ def blen_read_geom_array_mapped_vert(
     if fbx_layer_mapping == b'ByVertice':
         if fbx_layer_ref == b'Direct':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride, item_size,
+                                                    descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     elif fbx_layer_mapping == b'AllSame':
         if fbx_layer_ref == b'IndexToDirect':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_allsame(len(blen_data)),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_allsame(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                     item_size, descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     else:
@@ -907,7 +1078,7 @@ def blen_read_geom_array_mapped_vert(
 
 
 def blen_read_geom_array_mapped_edge(
-        mesh, blen_data, blen_attr,
+        mesh, blen_data, blen_attr, blen_dtype,
         fbx_layer_data, fbx_layer_index,
         fbx_layer_mapping, fbx_layer_ref,
         stride, item_size, descr,
@@ -915,15 +1086,15 @@ def blen_read_geom_array_mapped_edge(
         ):
     if fbx_layer_mapping == b'ByEdge':
         if fbx_layer_ref == b'Direct':
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride, item_size,
+                                                    descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     elif fbx_layer_mapping == b'AllSame':
         if fbx_layer_ref == b'IndexToDirect':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_allsame(len(blen_data)),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_allsame(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                     item_size, descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     else:
@@ -933,7 +1104,7 @@ def blen_read_geom_array_mapped_edge(
 
 
 def blen_read_geom_array_mapped_polygon(
-        mesh, blen_data, blen_attr,
+        mesh, blen_data, blen_attr, blen_dtype,
         fbx_layer_data, fbx_layer_index,
         fbx_layer_mapping, fbx_layer_ref,
         stride, item_size, descr,
@@ -945,22 +1116,22 @@ def blen_read_geom_array_mapped_polygon(
             #     We fallback to 'Direct' mapping in this case.
             #~ assert(fbx_layer_index is not None)
             if fbx_layer_index is None:
-                blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                             blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+                blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                        item_size, descr, xform)
             else:
-                blen_read_geom_array_setattr(blen_read_geom_array_gen_indextodirect(fbx_layer_index, stride),
-                                             blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+                blen_read_geom_array_foreach_set_indexed(blen_data, blen_attr, blen_dtype, fbx_layer_data,
+                                                         fbx_layer_index, stride, item_size, descr, xform)
             return True
         elif fbx_layer_ref == b'Direct':
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride, item_size,
+                                                    descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     elif fbx_layer_mapping == b'AllSame':
         if fbx_layer_ref == b'IndexToDirect':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_allsame(len(blen_data)),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_allsame(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                     item_size, descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     else:
@@ -970,7 +1141,7 @@ def blen_read_geom_array_mapped_polygon(
 
 
 def blen_read_geom_array_mapped_polyloop(
-        mesh, blen_data, blen_attr,
+        mesh, blen_data, blen_attr, blen_dtype,
         fbx_layer_data, fbx_layer_index,
         fbx_layer_mapping, fbx_layer_ref,
         stride, item_size, descr,
@@ -982,29 +1153,29 @@ def blen_read_geom_array_mapped_polyloop(
             #     We fallback to 'Direct' mapping in this case.
             #~ assert(fbx_layer_index is not None)
             if fbx_layer_index is None:
-                blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                             blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+                blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                        item_size, descr, xform)
             else:
-                blen_read_geom_array_setattr(blen_read_geom_array_gen_indextodirect(fbx_layer_index, stride),
-                                             blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+                blen_read_geom_array_foreach_set_indexed(blen_data, blen_attr, blen_dtype, fbx_layer_data,
+                                                         fbx_layer_index, stride, item_size, descr, xform)
             return True
         elif fbx_layer_ref == b'Direct':
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_direct(fbx_layer_data, stride),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_direct(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride, item_size,
+                                                    descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     elif fbx_layer_mapping == b'ByVertice':
         if fbx_layer_ref == b'Direct':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_direct_looptovert(mesh, fbx_layer_data, stride),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_looptovert(mesh, blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                        item_size, descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     elif fbx_layer_mapping == b'AllSame':
         if fbx_layer_ref == b'IndexToDirect':
             assert(fbx_layer_index is None)
-            blen_read_geom_array_setattr(blen_read_geom_array_gen_allsame(len(blen_data)),
-                                         blen_data, blen_attr, fbx_layer_data, stride, item_size, descr, xform)
+            blen_read_geom_array_foreach_set_allsame(blen_data, blen_attr, blen_dtype, fbx_layer_data, stride,
+                                                     item_size, descr, xform)
             return True
         blen_read_geom_array_error_ref(descr, fbx_layer_ref, quiet)
     else:
@@ -1029,7 +1200,7 @@ def blen_read_geom_layer_material(fbx_obj, mesh):
 
     blen_data = mesh.polygons
     blen_read_geom_array_mapped_polygon(
-        mesh, blen_data, "material_index",
+        mesh, blen_data, "material_index", np.uintc,
         fbx_layer_data, None,
         fbx_layer_mapping, fbx_layer_ref,
         1, 1, layer_id,
@@ -1063,7 +1234,7 @@ def blen_read_geom_layer_uv(fbx_obj, mesh):
                 continue
 
             blen_read_geom_array_mapped_polyloop(
-                mesh, blen_data, "uv",
+                mesh, blen_data, "uv", np.single,
                 fbx_layer_data, fbx_layer_index,
                 fbx_layer_mapping, fbx_layer_ref,
                 2, 2, layer_id,
@@ -1103,7 +1274,7 @@ def blen_read_geom_layer_color(fbx_obj, mesh, colors_type):
                 continue
 
             blen_read_geom_array_mapped_polyloop(
-                mesh, blen_data, color_prop_name,
+                mesh, blen_data, color_prop_name, np.single,
                 fbx_layer_data, fbx_layer_index,
                 fbx_layer_mapping, fbx_layer_ref,
                 4, 4, layer_id,
@@ -1137,11 +1308,11 @@ def blen_read_geom_layer_smooth(fbx_obj, mesh):
 
         blen_data = mesh.edges
         blen_read_geom_array_mapped_edge(
-            mesh, blen_data, "use_edge_sharp",
+            mesh, blen_data, "use_edge_sharp", bool,
             fbx_layer_data, None,
             fbx_layer_mapping, fbx_layer_ref,
             1, 1, layer_id,
-            xform=lambda s: not s,
+            xform=np.logical_not,
             )
         # We only set sharp edges here, not face smoothing itself...
         mesh.use_auto_smooth = True
@@ -1149,7 +1320,7 @@ def blen_read_geom_layer_smooth(fbx_obj, mesh):
     elif fbx_layer_mapping == b'ByPolygon':
         blen_data = mesh.polygons
         return blen_read_geom_array_mapped_polygon(
-            mesh, blen_data, "use_smooth",
+            mesh, blen_data, "use_smooth", bool,
             fbx_layer_data, None,
             fbx_layer_mapping, fbx_layer_ref,
             1, 1, layer_id,
@@ -1160,8 +1331,6 @@ def blen_read_geom_layer_smooth(fbx_obj, mesh):
         return False
 
 def blen_read_geom_layer_edge_crease(fbx_obj, mesh):
-    from math import sqrt
-
     fbx_layer = elem_find_first(fbx_obj, b'LayerElementEdgeCrease')
 
     if fbx_layer is None:
@@ -1192,13 +1361,13 @@ def blen_read_geom_layer_edge_crease(fbx_obj, mesh):
 
         blen_data = mesh.edges
         return blen_read_geom_array_mapped_edge(
-            mesh, blen_data, "crease",
+            mesh, blen_data, "crease", np.single,
             fbx_layer_data, None,
             fbx_layer_mapping, fbx_layer_ref,
             1, 1, layer_id,
             # Blender squares those values before sending them to OpenSubdiv, when other software don't,
             # so we need to compensate that to get similar results through FBX...
-            xform=sqrt,
+            xform=np.sqrt,
             )
     else:
         print("warning layer %r mapping type unsupported: %r" % (fbx_layer.id, fbx_layer_mapping))
@@ -1223,22 +1392,28 @@ def blen_read_geom_layer_normal(fbx_obj, mesh, xform=None):
         print("warning %r %r missing data" % (layer_id, fbx_layer_name))
         return False
 
-    # try loops, then vertices.
+    # Normals are temporarily set here so that they can be retrieved again after a call to Mesh.validate().
+    bl_norm_dtype = np.single
+    item_size = 3
+    # try loops, then polygons, then vertices.
     tries = ((mesh.loops, "Loops", False, blen_read_geom_array_mapped_polyloop),
              (mesh.polygons, "Polygons", True, blen_read_geom_array_mapped_polygon),
              (mesh.vertices, "Vertices", True, blen_read_geom_array_mapped_vert))
     for blen_data, blen_data_type, is_fake, func in tries:
-        bdata = [None] * len(blen_data) if is_fake else blen_data
-        if func(mesh, bdata, "normal",
-                fbx_layer_data, fbx_layer_index, fbx_layer_mapping, fbx_layer_ref, 3, 3, layer_id, xform, True):
+        bdata = np.zeros((len(blen_data), item_size), dtype=bl_norm_dtype) if is_fake else blen_data
+        if func(mesh, bdata, "normal", bl_norm_dtype,
+                fbx_layer_data, fbx_layer_index, fbx_layer_mapping, fbx_layer_ref, 3, item_size, layer_id, xform, True):
             if blen_data_type == "Polygons":
-                for pidx, p in enumerate(mesh.polygons):
-                    for lidx in range(p.loop_start, p.loop_start + p.loop_total):
-                        mesh.loops[lidx].normal[:] = bdata[pidx]
+                # To expand to per-loop normals, repeat each per-polygon normal by the number of loops of each polygon.
+                poly_loop_totals = np.empty(len(mesh.polygons), dtype=np.uintc)
+                mesh.polygons.foreach_get("loop_total", poly_loop_totals)
+                loop_normals = np.repeat(bdata, poly_loop_totals, axis=0)
+                mesh.loops.foreach_set("normal", loop_normals.ravel())
             elif blen_data_type == "Vertices":
                 # We have to copy vnors to lnors! Far from elegant, but simple.
-                for l in mesh.loops:
-                    l.normal[:] = bdata[l.vertex_index]
+                loop_vertex_indices = np.empty(len(mesh.loops), dtype=np.uintc)
+                mesh.loops.foreach_get("vertex_index", loop_vertex_indices)
+                mesh.loops.foreach_set("normal", bdata[loop_vertex_indices].ravel())
             return True
 
     blen_read_geom_array_error_mapping("normal", fbx_layer_mapping)
@@ -1348,9 +1523,8 @@ def blen_read_geom(fbx_tmpl, fbx_obj, settings):
         if geom_mat_no is None:
             ok_normals = blen_read_geom_layer_normal(fbx_obj, mesh)
         else:
-            def nortrans(v):
-                return geom_mat_no @ Vector(v)
-            ok_normals = blen_read_geom_layer_normal(fbx_obj, mesh, nortrans)
+            ok_normals = blen_read_geom_layer_normal(fbx_obj, mesh,
+                                                     lambda v_array: nors_transformed(v_array, geom_mat_no))
 
     mesh.validate(clean_customdata=False)  # *Very* important to not remove lnors here!