Julian Eisel
604e61d81d
Adds `NODE_OT_add_group` operator to add a node group from a given name, and uses that to register a node editor drop-box. When dropping a node-group asset, the ID will be appended. This is what we do for other ID assets too. Should the node group insertion fail (e.g. the group is not compatible with the current tree, as checked by the poll), the appended data-block is removed. Differential Revision: https://developer.blender.org/D10405 Reviewed by: Jacques Lucke