Tri's vs. Quads in LP

i got my hands on some of call of duty MW3 weapon models and it was almost only tris and no quad for example G36 in CoD has only 3861 tris

hope this help you

Interesting question!

There is no simple answer for this but often it better to work with quads as it's easier to model with them and the meshes look cleaner, but when in game, all meshes are automatically converted to triangles anyway which can cause issues if the triangulation is different to what you were expecting.

Generally its better to convert you meshes into triangles manually so you have the control as to how they are triangulated and then bake your maps so you know that the normal map will match the geometry on the asset 100% (You cant do this with quads unless the same triangulation algorithm is used bu the application/engine)

Now after saying all that, the number you really should be paying attention too is the vert. count as they can grow at a pretty fast rate if you don't keep track of them...Triangles are only used as a guide and are really not very accurate as a gauge for performance.

But yea, 5k tris really isnt that much for a first person gun in modern games, so I wouldn't worry too  much...as long as you are not wasting the geo, you should be fine

Those UVs look fine, thought they could do with a little more space between the UV islands. On a 2k map you prob want somewhere between 8 and 16px gap between each island, which will stop mip errors etc.

You want to keep as much as you can as single smoothing groups and break the UV's in UV space wherever there is a smoothing group border in 3d space. This should stop some of the seams that you might be getting. Also, did you use a cage in xNormal? That could be the reason that you are getting seams as without a cage xNormal uses a uniform ray distance which doesnt play well with smoothing groups and will cause seams at the edges where the rays are missed.

In regards to the tris in the game engine...All meshes are rendered as triangles and this is before tessellation. Even if you export the mesh as quads, the engine with triangulate the mesh for you, which is why its a good idea that you triangulate it yourself before you bake and export, because the engine might triangulate the mesh with a different method and therefore the geometry that you baked with might not necessarily match the mesh when its in the game engine and as a result the normal map might be wrong. Sometimes this isn't noticeable, but on other occasions it is, so it's good practice to always triangulate before baking and exporting....at least then you have 100% control

As for the quads, its good to model in quads because its cleaner and most modeling tools require quads for maximum effectiveness, but in reality quads are a lie. It's all tris (even in Max) even if its displayed as quads/ngons

Smoothing groups are the same thing as hard edges, though rather than marking the edges as hard, you mark the faces instead. The script sounds great, so its good that you are already using it.