Support Blender 3.x alongside 4.x

api/tree.py

@@ -16,6 +16,8 @@
 from .static.simulation import *
 from .arrange import _arrange
 
+IS_BLENDER_4 = bpy.app.version[0] >= 4
+
 def _as_iterable(x):
     if isinstance(x, Type):
         return [x,]
@@ -24,8 +26,16 @@ def _as_iterable(x):
     except TypeError:
         return [x,]
 
-get_node_inputs = lambda x: [i for i in x.interface.items_tree if i.item_type == 'SOCKET' and i.in_out == 'INPUT']
-get_node_outputs = lambda x: [i for i in x.interface.items_tree if i.item_type == 'SOCKET' and i.in_out == 'OUTPUT']
+def get_node_inputs(x):
+    if IS_BLENDER_4:
+        return [i for i in x.interface.items_tree if i.item_type == 'SOCKET' and i.in_out == 'INPUT']
+    else:
+        return x.inputs
+def get_node_outputs(x):
+    if IS_BLENDER_4:
+        return [i for i in x.interface.items_tree if i.item_type == 'SOCKET' and i.in_out == 'OUTPUT']
+    else:
+        return x.outputs
 
 def tree(name):
     tree_name = name
@@ -39,7 +49,8 @@ def build_tree(builder):
         else:
             node_group = bpy.data.node_groups.new(tree_name, 'GeometryNodeTree')
 
-        node_group.is_modifier = True
+        if IS_BLENDER_4:
+            node_group.is_modifier = True
 
         # Clear the node group before building
         for node in node_group.nodes:
@@ -48,10 +59,16 @@ def build_tree(builder):
         node_inputs = get_node_inputs(node_group)
         input_count = sum(map(lambda p: len(p.annotation.__annotations__) if issubclass(p.annotation, InputGroup) else 1, list(signature.parameters.values())))
         for node_input in node_inputs[input_count:]:
-            node_group.interface.remove(node_input)
+            if IS_BLENDER_4:
+                node_group.interface.remove(node_input)
+            else:
+                node_group.inputs.remove(node_input)
 
         for group_output in get_node_outputs(node_group):
-            node_group.interface.remove(group_output)
+            if IS_BLENDER_4:
+                node_group.interface.remove(group_output)
+            else:
+                node_group.outputs.remove(group_output)
 
         # Setup the group inputs
         group_input_node = node_group.nodes.new('NodeGroupInput')
@@ -80,7 +97,10 @@ def validate_param(param):
         for i, node_input in enumerate(node_inputs):
             if node_input.bl_socket_idname != list(inputs.values())[i][0].socket_type:
                 for ni in node_inputs:
-                    node_group.interface.remove(ni)
+                    if IS_BLENDER_4:
+                        node_group.interface.remove(ni)
+                    else:
+                        node_group.inputs.remove(ni)
                 break
         builder_inputs = {}
 
@@ -91,7 +111,10 @@ def validate_param(param):
                 node_inputs[i].name = input_name
                 node_input = node_inputs[i]
             else:
-                node_input = node_group.interface.new_socket(socket_type=arg[1][0].socket_type, name=input_name, in_out='INPUT')
+                if IS_BLENDER_4:
+                    node_input = node_group.interface.new_socket(socket_type=arg[1][0].socket_type, name=input_name, in_out='INPUT')
+                else:
+                    node_input = node_group.inputs.new(arg[1][0].socket_type, input_name)
             if arg[1][1] != inspect.Parameter.empty:
                 node_input.default_value = arg[1][1]
             if arg[1][2] is not None:
@@ -118,14 +141,20 @@ def validate_param(param):
             for i, (k, v) in enumerate(outputs.items()):
                 if not issubclass(type(v), Type):
                     v = Type(value=v)
-                node_group.interface.new_socket(socket_type=v.socket_type, name=k, in_out='OUTPUT')
+                if IS_BLENDER_4:
+                    node_group.interface.new_socket(socket_type=v.socket_type, name=k, in_out='OUTPUT')
+                else:
+                    node_group.outputs.new(v.socket_type, k)
                 node_group.links.new(v._socket, group_output_node.inputs[i])
         else: 
             for i, result in enumerate(_as_iterable(outputs)):
                 if not issubclass(type(result), Type):
                     result = Type(value=result)
                     # raise Exception(f"Return value '{result}' is not a valid 'Type' subclass.")
-                node_group.interface.new_socket(socket_type=result.socket_type, name='Result', in_out='OUTPUT')
+                if IS_BLENDER_4:
+                    node_group.interface.new_socket(socket_type=result.socket_type, name='Result', in_out='OUTPUT')
+                else:
+                    node_group.outputs.new(result.socket_type, 'Result')
                 node_group.links.new(result._socket, group_output_node.inputs[i])
 
         _arrange(node_group)