Hey guys,
I am a programmer but i can help myself a little in 3d programs so i was doing some test's on a game engine i just found and downloaded some 3d models but i noticed that allot of the models come detached with different maps assigned to them.
for example if i download a human model i may find the model split into 2 parts : head and body and each has its own bitmap file to it...

now my question is : is there a way that when i attach these 2 objects i can let 3ds max automatically combine these texture maps automatically for me or do i need to reskin the model completely?
Thank you in advanced.

• Open one of the bitmap files, increase its canvas-size until it can fit the other bitmap (or at least all important parts of it). This will be your texture atlas, and it should be power-of-2.
  • Go to 3DS Max, convert both body parts to Editable Poly and Attach the head to the body or vice-versa. Now you have a single mesh. 
  • Apply the texture atlas to this single mesh. Both body parts, now combined, will probably be mis-textured.
  • Add an UVW Unwrap modifier to this single mesh.
  • Select all the UV faces of one of the body parts, and align it with the corresponding parts of the texture map. Do the same for the other part. You will probably have to both move and scale the collections of UV faces (since the texture got bigger), so this will be tricky to get right. Take your time.
    I think this should solve your problem.
    
    There are free and commercial plugins for this package that do the above, but it's a matter of googling. Try these keywords: "3DS Max texture atlas generator plugin".