Objects rendering improperly

I’m the lead programmer for a game, so I’m completely unsure of how to approach this problem- I’ve got zero experience with 3d models and such. The person who made the models is busy with college so it’s up to me for now. In any event, I have an issue with the rendering of viewmodels in the game- as you can see in the below image, the “insides” of the viewmodel are rendering what seems to be on top of what should be there. It renders fine in other applications, and as such I’ve posted a picture of what the model should look like as well. So why is this happening in Unity? I tested it off the camera, away from the main cam, in the editor, etc, and the issue only occurs in Unity.

@xthunderduckx Looks like an issue with face normals being pointed backward. My guess is if you were to look at this model in blender and turn on face orientation you’ll see this.

Unity only renders one side of every plane for performance reasons. Red planes are only gonna be visible from the inside (not what you want). To fix this select all the faces that are red from the outside and flip their normals. It should all be blue from the outside. Then export and you should be good. Best of luck!