VMF Importer
You can use Wall Worm to import a VMF into 3ds Max. This allows you to bring in your Hammer project into 3ds Max.
VMT Browser
The VMT Browser in Wall Worm allows you to browse, preview and assign materials from your game.
Convert Scene to Model
Instructions on converting a scene into a model or clustering multiple model props into single models.
DXF Importer
You can import a DXF scene into Max. This allows you to transfer the basic level design from Hammer to Max.
Overview Exporter
The Overview/Radar texture exporter allows you to export an overview texture straight from your Max scene.
Visgroup Manager
The Visgroup Manager in Wall Worm allows you to arbitrarily show/hide objects in your scene.
VMF Exporter
The Wall Worm tools allows you to send your 3ds Max scene to Hammer and Source via a VMF Exporter.
Why are Models Appearing as Cubes?
When reopening a scene the models can appear as cubes if the game settings do not include paths to the source MDL files.
This document explains why models can appear as cubes instead of props when importing VMF or MDL nodes.