Objects with more than one texture

[WALP]

You just need to make the parts of your model that uses a different texture into a seperate objects and export it all together.
Not only will this allow you to have different textures on your model but it will also make amnesia recognice the different objects as "submeshes", which can be editted seperately in model editor to create entities with more advances physics and properties and such.

Also just like to stress that .dds is not required, its just good because better performance and mip-maps

EDIT: also to use an amnesia texture just assign it strait from the 3d software you are using.
amnesia will be able to find the material as long as the diffuse(color) is assigned to your model-