Hello @herrmay,

Thank you for reaching out to us and no worries, we are here to answer your questions. That your material browser does not update is not too surprising, because you never update the data.

The classic API does not have a too granular event system and one is often forced to react to the very broad core message EVMSG_CHANGE which just conveys that something has changed in a scene, e.g., a material has been add, removed, renamed, etc. - or that the polygon object in the top left corner of the active camera changed its opinion about what is its favorite vertex 🙂 So, EVMSG_CHANGE is being fired a lot and reacting to it directly can produce unwanted overhead or, when you do not care about overhead, can lead to unwanted behaviours when a system updates when it is not meant to update.

You implement a dialog here which receives such core messages via GeDialog.CoreMessage, you even use some code which has 90% of the work done. You just have to update you actual data when the message is being fired.

def CoreMessage(self, id, msg): if id == c4d.EVMSG_CHANGE: # Reinitialize the object tree so that it reflects the new scene state. We could write # custom code or be lazy like me and reuse InitValues() :) . In practice you might want # to be a bit more selective about when you reinitialize your ObjectTree, as doing # so will flush the selection state etc. You could for example by caching a list of # UUIDs of all materials and on every EVMSG_CHANGE check if something about this list # changed, i.e., if a material has been added or removed. If you would also track # the data container dirty count of each material in that list, you would have a pretty # water tight "on_material_data_change" event. # # The alternative would be to fashion your ObjectTree so that a running instance can # be updated with scene data. In both cases you will need a solid understanding of # node UUIDs to identify materials as Python's id() will not work due to nodes being # reallocated. Here we talked about them in the context of materials: # https://plugincafe.maxon.net/topic/14266/ # You can find more UUID posting made by me under: # https://plugincafe.maxon.net/search?term=UUID&in=titlesposts&by[]=ferdinand self.InitValues() self._tree_gui.Refresh() return True

As lined out in the comment, there are more complex approaches to this. It might also be a good idea to read the Message System Manual

Cheers,
Ferdinand

Result
materials.gif

UNSOLVED Add Field to Effector