How do you add another skin option to a model?

I have recently been interested in making some custom skin options for a few props. I don’t want to overwrite the original texture, just add another skin option. I have been trying to follow some guides but have had no success. Here’s what I have done so far.

The models I want to edit are Workshop downloads. Not a problem, just put the .gma file into gmad.exe and it will extract the contents into the addon folder. I cleaned up the materials and models folder to just have the props I want to customize. I opened VTFedit and went into the materials folder and looked for one of the already existing skins. I copied the picture size and went to work on making a custom skin. Once I finished, I imported it into VTFedit and saved it as a VTF file. I named the file after one of the other skins but changed the number to add an extra skin.

Example
Original Skin options: poster_skin1.vtf, poster_skin2.vtf
My custom skin: poster_skin3.vtf

Then I looked at one of the vmt files from the already existing skins and copied the text but once again changed the number to add an extra skin.

Example
Basic text structure: “$basetexture” “models/props_office/poster_skin#” [DEL](This text in the parenthesis isn’t in the vmt file. The # would equal 1 and 2.)[/DEL]
“$model” “1”
My custom skin text: “$basetexture” “models/props_office/poster_skin3”
“$model” “1”

Now I go into Gmod to test it. The Workshop item has the extra skin option but it shows as a missing texture. The extracted .gma folder is in addons. So I went there to see if the skin option works there. I spawn the prop but it doesn’t have another skin option.

What’s going on and how do I fix this?

This is a question better suited for the modeling forum.

this should be helpful https://developer.valvesoftware.com/wiki/Multiple_Skins_for_a_Single_Model

I had to load the page with the Wayback Machine to get it to load for some reason. Anyways, the model I’m trying to work on doesn’t do what the web page says. It just has a .vmt for each skin separate. Will I have to rewrite all the vmts to match what the site says just to get this to work? If that’s the case then how do I make the copied addon not overwrite the original Workshop version?

it going to over write the workshop addon because you’ve edited the model, you only have to add one in the .vmt and thats the line for the new skin plus add a line in the models .qc so the new skin is accepted by the model