I was wondering if someone could take a look and see if they could help me figure out an issue I have with substance... I've imported this mesh from blender with unwrapped uvs and seperate materials. However parts of the mesh disappear when moving the camera. Here is a photo to illustrate. Look at the buttstock, as it is the most obvious example.
Moving the camera will make that missing part rotate on the closest side to the camera.
Go back to Blender and check the normals. I usually see that when the normals are reversed.
I have moved your post from the Substance Designer forum to the Substance Painter forum which is the application shown in your screenshot.