Generating LODs
The Level of Detail Generator on the Level of Detail Tools Rollout lets you generate LOD models from the root mesh. The tool will make lower-res versions of your model so that less polygons are rendered in-game when players move farther away.
Attachments & Particle System UI
Attachments are points on your model where you can attach extra models and particle systems (guns, sprites, etc). This page details both Attachments and Particle Systems since the Particle System controls are also in the attachment rollout.
Exporting CAT and Biped Models
Export your CAT or Biped rig from 3ds Max into the Source Game Engine with Wall Worm.
Using 4Way Blends

Overview of creating and working with Lightmapped_4WayBlend shaders in Wall Worm.
Advanced Bone Settings
Information on adding bones to your model or controlling advanced parameters.
On the Grid
Information and videos on using the grid in 3ds Max for Source Engine Level Design.
Exporting Correct Smoothing on Models
Understanding Smoothing Groups and Explicit Normals
Discussion on smoothing groups and explicit normals and how they relate to Source.
Porting Levels into Source
General Overview of Converting Scenes that Were Not Designed with Source in Mind
Overview on porting scenes and levels from other sources.
Wrinklemaps
Instructions on making wrinklemaps in 3ds Max with Wall Worm Pro.
Wall Worm 4, 3ds Max 2020 and Black Mesa News

Wall Worm 4.0 Released and other news about 3ds Max.