On 20/11/2015 at 11:52, xxxxxxxx wrote:
The icons are all in an external file so you can edit them with a paint program, so if it's only the default icon, you can do that...
(I am rarely doing that any more b/c the icons are changed with every version, being all in one single file... but sometimes it helps with a custom interface)
If you want to change the icon dynamically depending on some settings, then that won't work of course. Ultimately the object tells the C4D GUI which icon it wants to use, I don't think that you can control that from the outside.
However: A Null object doesn't exactly do a lot beyond the default behavior of a BaseObject. So, you may be able to program (in a simple way) a Python or C++ object that provides no geometry, essentially being a Null. This object could show any icon you want, even dynamically, and you might provide a way to change the icon from the outside by sending it self-defined messages, or by providing a method for direct access by other objects.