Sort filenames in natural numerical order (#15)

* sort in numerical order

* improve efficiency and code style

* update README

* Update README.md

README.md

@@ -10,9 +10,6 @@ Bitcoin wallet: 16Bbv5jmKJ2T3dqw2rbaiL6vsoZvyNvaU1
 PayPal: https://www.paypal.me/justinj
 
 ### IMPORTANT
-- File numbers must be zero-padded
-  - Like this: file001, file002, file003
-  - NOT like this: ~~file1, file2, file3~~
 - You MUST restart Blender after enabling the add-on
 
 ### Features
@@ -29,7 +26,9 @@ PayPal: https://www.paypal.me/justinj
 
 ### Limitations
 - Only absolute filepaths are supported (for now)
-- File numbers must be zero-padded
+- ~~File numbers must be zero-padded~~
+  - Sorting file with correct order is added in [this PR](https://github.com/neverhood311/Stop-motion-OBJ/pull/15)
+  - Files like file1, file2, file3 will be loaded in correct order, and zero-padded filenames still work, too.
 - No motion blur
 - ~~Doesn't work with physics~~ 
   - (It actually works with rigid body physics. In Rigid Body Collisions set Shape to 'Mesh' and Source to 'Base')

mesh_sequence_controller.py

@@ -34,9 +34,16 @@
 
 import bpy
 import os
+import re
 import glob
 from bpy.app.handlers import persistent
 
+def alphanumKey(string):
+    """ Turn a string into a list of string and number chunks.
+        "z23a" -> ["z", 23, "a"]
+    """
+    return [int(c) if c.isdigit() else c for c in re.split('([0-9]+)', string)]
+
 #global variable for the MeshSequenceController
 MSC = None
 
@@ -165,7 +172,9 @@ def loadSequenceFromFile(self, _obj, _dir, _file):
         print(full_filepath)
         numFrames = 0
         unsortedFiles = glob.glob(full_filepath)
-        sortedFiles = sorted(unsortedFiles)
+        # Sort the given list in the way that humans expect.
+        sortedFiles = sorted(unsortedFiles, key=alphanumKey)
+
         #for each file that matches the glob query:
         for file in sortedFiles:
             #import the mesh file
@@ -617,4 +626,4 @@ def unregister():
     bpy.types.INFO_MT_mesh_add.remove(menu_func)
 
 if __name__ == "__main__":
-    register()
+    register()