Attaching a prop to a human model?

I’m working in L4D2 and as NPC’s are not creatable, I’m getting by with human models with animations. I get by using the weapon models, and setting the human model to an animation where he’s holding a gun. I then move the gun prop into his hands. However, I can’t go any further than that, because if I animate the human model again the gun doesn’t move with him.

Is there any way I can make said gun move with him in Hammer?

Use the SetParentAttachment input. (

You can find the human models attachment names in model viewer.

Wow! Thanks! It works perfectly!