Hello, I'm looking for what, in the game, links together the "icon" value of a RDNode to the real icon. TechTree{ RDNode { id = start title = Start description = The technology we started out with. cost = 0 hideEmpty = False nodeName = node0_start anyToUnlock = False icon = RDicon_start <=== How does it match "R&D_node_icon_start.png" ??? pos = -2568,1199,-1 scale = 0.6 } I've found that this value is not a filename, because even if it is close for some of them, you cannot achieve the match from the value to the images stored into GameData/Squad/PartList/SimpleIcons through a simple transformation. A simple example that made me first think the icon is the filename is the "Science Tech" node that uses the last icon file (by alphabetic order) RDicon_telescope.png It matches the "icon" value as "RDicon_telescope". I expected then it was the filename without its expansion. Then I realized that some "R&D_node_icon_*" files requires that "R&D_node_icon_*" part to be replaced to "RDicon_*". Finally I came to the "Basic Rocketry" tech node (the first in the config not to fit my rules) and the transformation is not trivial at all. You cannot, by general operation on strings, go from "RDicon_rocketry-basic" to "R&D_node_icon_basicrocketry.png". There must then be some kind of database that makes these matches. But I can't find where. I know it's not in any .cfg file but that's all I know. Adding a node with a matching "icon" value and filename doesn't help, it changes the display to "R&D_node_icon_generic.png" Does someone knows how to add a new icon into the tech tree ? Thanks