MultiMatte Tamer is a MaxScript from secondplace that helps set Object IDs and store V-Ray MultiMatte Render Elements in 3ds Max. Scene objects are selected within a grid table, and the script only works when objects and layers are recognized by their names.
The interface centers on a handful of controls. Add Button adds another numbered ID button, while Refresh reloads the scene's objects and recognizes any ID that has been manually changed, adding further buttons if required. Collect uses all RGB slots rather than sequential ones, Selected lists only the objects currently selected, and the Filter input selects all matches in the names column. The Elements button creates render elements from the selection, following Collect when it is checked. Double-clicking a cell selects the same OIDs, all items within a layer, or all related names ending with a number.
Creating render elements needs V-Ray, since MultiMatteElement is part of V-Ray; without it the Elements button is hidden, though Object IDs can still be set. Version 1.2.4 adds HD mode and sets IDs using unique identifiers instead of names.