MultiSub Organizer is a tool from pixamoon for 3ds Max, built to organize large Multi/Sub-Object materials alongside the Face IDs they are linked to within EditPoly or EditMesh. It presents a material list you load by selecting a material in the Material Editor and clicking 'From Material', then works with its IDs and the faces assigned to them.
The tool keeps materials and geometry aligned through synchronized ID updates, applying a new ID to both the material and its linked Face IDs at once. You target changes with the Mtls and Faces checkboxes, assign IDs from number buttons, and sort the list by Slot, ID, Name, Material Name, or Material Class. Bidirectional selection lets you select faces by ID and find objects linked with a material.
Statistics and diagnostics round out the list: face counts per ID, object counts per material, and error tracking that highlights unassigned Face IDs in red. It can list several Multi/Sub-Object materials at once, though for applying new IDs the developer recommends handling one material at a time.