[3DS MAX]Mixing 2 different model maps together

[Lil Margin]

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.

[shadowslair]

Unless combining the two is not forming a new, POT texture once again, there`s no much sense to combine them. For example a body texture of 512x512 and a head texture of 128x128 will form 640x512 or 512x640 texture and you`ll put much more problems on your head with wasted texture space(hence wasted memory), and all the nonPOT problems. If for example both textures are 512x512 or 256x512, you can easily put them next to each other let`s say horizontally (on U). Then, in Max you set the new, twice bigger resolution of the texture, apply it to both objects (they`re not attached in one yet, or attached, but using seperate polygroups, elements or whatever to make the uvs easier to grab at once). Then your uvs will be stretched horizontally, so you`ll grab them all and scale them by half on U and position them properly- the body uvs over the body map half, and the head uvs on the head half of the texture. Once done, you attach the two objects and you`re ready. Once again, doing that should have some reason behind it- you cannot expect big performance boost on Irrlicht side, for using one material, and saving one material switch, unless you have many models like over 50, and bigger texture variety like over say 10 textures, spread randomly (on the over 50 models). You`ll lose the ability to customize each body texture with each head texture etc. If I was you, I wouldn`t do that, unless I need to.

3ds max automatically combine these texture maps automatically for me or do i need to reskin the model completely?

If you have a skinned mesh, you`ll better do the above and not attach the two objects, but export them as one model file. If with "reskin" you meant "unwrap again", then no, you can do the gymnastics I mentioned above. As for doing this automatically- there are many plugins for helping unwrapping, you can try some of them, but I personally don`t find it neccessary, as it`s a 5 minutes work anyway.

[serengeor]

You could just merge the vertices and use separate mesh buffers I think. As for automatic, I don't think 3ds max has the AI to know which things it has to merge, so I guess you'll have to get your hands dirty here.

[Virion]

in maya there is a feature called Texture Wrapping. It does automatically combine the UV together in a neat way. I saw my colleagues doing that but I personally never tried it.