fix(shader): Prevent resetting parameters in shader settings

Introduce an early return check for the shader's variation. If the selected variation is the same as the previously active one, the function exits early, preventing any unnecessary resetting of shader parameters.

Fix StjerneIdioten#180

addon/i3dio/ui/shader_picker.py

@@ -253,6 +253,8 @@ def variation_items_update(self, context):
                            )
 
     def variation_setter(self, value):
+        if self.get('variation') == value:
+            return
         self['variation'] = value
         bpy.ops.i3dio.load_custom_shader_variation()