How Should I Approach Texturing a Model Like This?

NURBS

So I'm trying to get into Unity and as practice I'm modeling, texturing and will eventually animate a Humvee to bring into Unity. My goal is to make this thing so it can drive around and have other moving parts. I'm pretty confident that I can figure that out, but I'm struggling with how to approach texturing it. How are models like this usually texture? Is it all in one texture set or is each animated piece its own object? I would really like some help on this.

Here is this model I am working with:

I also want to try and get the suspension (or whatever it's called) animated as well so I can have the wheels when it goes over bumpy terrain like in real life.

kanga

If you want to use substance then uv the model and seperate the uvs so that adjacent parts are in a different set. Ive never baked without a hipoly version before so Im not sure what you would do with smooth groups.

Eric Chadwick

Reuse UV space as much as possible. 

Duplicate parts like the wheels can be UVd once, then duplicated around, replacing the original parts.

Use symmetry too, only need to UV one side of the vehicle, then mirror the meshes and replace original parts. 

Grill, hood, windshield, roof, rear... probably not mirrored down the center line, rorschach patterns get really obvious.

Otherwise, reuse as much as possible. 

NURBS

How should I group objects together? For example: I want to have the doors be able to swing open, should I make each door its own object with its own texture set or have them all in the same one?

kanga

If there are no large dirt, wer and tear areas etc then before you do the uvs delete the parts that will be duplicated, for example the door on one side. Do the uvs and when done copy the door and flip it and position it. The uvs will be copied on top of the original door uvs. The mesh will be an independant piece though. Flipping the mesh wont flip the uvs. You can then rig the doors seperately.