Blender 2.8 - 4.5 Support

leenkx/blender/lnx/exporter_opt.py

@@ -2,8 +2,7 @@
 Exports smaller geometry but is slower.
 To be replaced with https://github.com/zeux/meshoptimizer
 """
-from typing import Optional
-
+from typing import Optional, TYPE_CHECKING
 import bpy
 from mathutils import Vector
 import numpy as np
@@ -21,7 +20,12 @@ else:
 class Vertex:
     __slots__ = ("co", "normal", "uvs", "col", "loop_indices", "index", "bone_weights", "bone_indices", "bone_count", "vertex_index")
 
-    def __init__(self, mesh: bpy.types.Mesh, loop: bpy.types.MeshLoop, vcol0: Optional[bpy.types.Attribute]):
+    def __init__(
+        self, 
+        mesh: 'bpy.types.Mesh', 
+        loop: 'bpy.types.MeshLoop', 
+        vcol0: Optional['bpy.types.MeshLoopColor' if bpy.app.version < (3, 0, 0) else 'bpy.types.Attribute']
+    ):
         self.vertex_index = loop.vertex_index
         loop_idx = loop.index
         self.co = mesh.vertices[self.vertex_index].co[:]