Now the editor loads and created nodes from MMNodes, and also implemented MMNode and graphnode creating logic for the add button/dialog.

game/addons/mat_maker_gd/editor/MatMakerGDEditor.gd

@@ -1,13 +1,63 @@
 tool
 extends MarginContainer
 
+var MMGraphNode = preload("res://addons/mat_maker_gd/editor/mm_graph_node.gd")
+
+export(NodePath) var graph_edit_path : NodePath = "VBoxContainer/GraphEdit"
 export(NodePath) var add_popup_path : NodePath = "Popups/AddPopup"
 
+var _graph_edit : GraphEdit = null
 
+var _material : MMMateial
+
+func _enter_tree():
+	ensure_objs()
+
+func ensure_objs() -> void:
+	if !_graph_edit:
+		_graph_edit = get_node(graph_edit_path)
+
+func recreate() -> void:
+	ensure_objs()
+	
+	for c in _graph_edit.get_children():
+		if c is GraphNode:
+			_graph_edit.remove_child(c)
+			c.queue_free()
+		
+	if !_material:
+		return
+		
+	for n in _material.nodes:
+		var gn : GraphNode = MMGraphNode.new()
+		gn.set_node(n)
+		_graph_edit.add_child(gn)
+		
+	#connect them
+
+func set_mmmaterial(object : MMMateial):
+	_material = object
+	
+	recreate()
 
 func _on_AddButton_pressed():
 	get_node(add_popup_path).popup_centered()
 
 func _on_AddPopup_ok_pressed(script_path : String):
-	#print(script_path)
-	pass
+	if !_material:
+		return
+	
+	ensure_objs()
+
+	var sc = load(script_path)
+	var nnode : MMNode = sc.new()
+	
+	if !nnode:
+		print("_on_AddPopup_ok_pressed: Error !nnode! script: " + script_path)
+		return
+	
+	_material.nodes.append(nnode)
+	
+	var gn : GraphNode = MMGraphNode.new()
+	gn.set_node(nnode)
+	_graph_edit.add_child(gn)

game/addons/mat_maker_gd/editor/mm_graph_node.gd

@@ -1,3 +1,7 @@
 tool
 extends GraphNode
 
+var _node : MMNode = null
+
+func set_node(node : MMNode) -> void:
+	_node = node

game/addons/mat_maker_gd/plugin.gd

@@ -36,7 +36,9 @@ func handles(object):
 func edit(object):
 	#if editor_scene:
 	#	make_bottom_panel_item_visible(editor_scene)
-	pass
+	
+	if object is MMMateial:
+		editor_scene.set_mmmaterial(object as MMMateial)
 	
 func make_visible(visible):
 	if tool_button: