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'[R-DEV wrote:Rhino;1786913']
Step 3: UVing your low poly 3p models

Now for UVing these objects you basically need to UV them in pretty much the same method you would UV a normal object but the only real difference is that your going to be UVing all these components onto the same sheet. How you go about this is up to you but what you need to end up with is all the components of this weapon series all UVed onto the same sheet, so all the L85 bits, L86, L22, AG36, all the scopes and other attachments need to be all on this single texture sheet.

I'm not going to go much into UVing methods so if you need to learn about UVing here is a pretty good tutorial: Creating a Weapon For Source download - Mod DB

There are a few thing you need to keep in mind when UVing objects for Baking which as a result you need to change a little bit on how you do your UVs.

The first thing is that you shouldn't have any overlaps on your UV as overlaps will come out really bad when baking as it will basically render the same/diffrent texture twice onto the same bit and even if the textures are excatly the same, the result will be diffrnet from if it wasn't overlapped, screwing up the baking. Different components mind you can be overlapped if the same and then you just have to fiddle around with them a little when you put all the baked textures together in photoshop but parts of the same mesh/component that are overlapped will come out really funny on the bake. Its possible to get around this either by hand painting or by only baking one bit by detaching it and baking it but this is only really worth it if your going to be saving a big chunk of space on your UV. So keep this in mind when your UVing and ask yourself if this this bit is really worth overlapping or not? Also keep in mind that one bit you might want to overlap might have a different texture on the main mesh and if so, the 1p and 3p models wont look the same which if its a large bit of the mesh could be a big issue.

The next big thing you need to keep in mind is that you can't stich bits of the model together with diffrent smoothing groups. If you have your UVs stiched together your normal (bump) maps will not come out right and there will be a big line/seem on the stiched part where two diffrent smothing groups meet.
Here's a quick example just encase your not sure what I'm on about using the butt of the SA80 rifle.
First of all the Smoothing groups, the top face uses smoothing group 3 (shown in blue) while the back (and underside) of the rifle uses smoothing group 2 (shown in red). As you can see the two smoothing groups meet at the very top of the back of the rifle.
Here is the stiched UV:

And in the render of the model after its been baked with a stiched UV, we can see a big black seam across where the two smoothing groups meet.

Now here the un-stiched UV:

And in the render of the model after its been baked with an un-stiched UV, we can see a big black seam across where the two smoothing groups meet.

Stiching UVs is something on a normal UV that is not having a texture baked to is something you should do at every oppitunity to make it as easy for the texture artist as possible to match up the textures on diffrent parts of the model. While this is some what still true for baking textures you should still stich up the UVs as much as possible, just dont stich up the UVs between two diffrent smoothing groups so make sure you know where your smoothing groups are and that you do not stich them up otherwise your normals are going to look totally rubbish and nothing like as good as they would otherwise. Even thou your UVs are not stiched, you can still put the faces that would be joined together much closer to each other than you would for a normal UV as any texture bleeding wont matter because the textures are the same on both sides, just make sure you have the right faces, the right way round next to each other. Simplest way to do this is to stich up your UVs then brake them at the points between two diffrent UVs.