Inisible textures/models

I am trying to figure out why a player model I compiled is transparent in a certain part. Like you can see the through the model and see the other side of it, but you can not see the front of area your looking at. Here is an example:

Does anyone know how to fix this?

add $opaque to the QC

I ended up editing the .vmt file and adding “$nocull” “1” but this is good to know. I actually recompiled this model and now the head is transparent so i am guessing it is because of one of these commands. The model int he picture was all one texture but I have changed it to were it is multiple ones now.

That’s a pretty cheap way of fixing it. The normals are just flipped.
http://www.fanhow.com/knowhow:Flip_normals_in_3ds_MAx_35682020

EPICFACEPALMS I was in a rush to finish this I totally forgot about the normals. I feel so stupid right now. I actually remember doing the flip normals in cinema 4d on the body and head. I guess I forgot to do that on the tail too.