From Valve Developer Community
See also Attachments.
$attachment <string|name> <string|parent bone> <Vector|offset> [absolute] [rigid] [rotate <angle|orientation>]
The optional commands are:
- Parented to the model's origin. The offset is still relative to the given parent bone, however!
- Declares that the bone this attachment is parented to will not move, allowing Studiomdl to optimise it out. Used to convert bones created in a modelling package into attachments.
- Rotates the attachment, in degrees, relative to its parent bone / the origin.
- To do: There is some weirdness in how the value is interpreted by Studiomdl.
Relative to bone:
$attachment "anim_attachment_RH" "ValveBiped.Anim_Attachment_RH" -0.00 -0.00 0.00 rotate -90.00 -90.00 0.00
Relative to origin (no bone name required):
$attachment "nozzle" "" 0 4.8 0 absolute