is there a mod to apply bodyslide to a new piece of equipment?

[wattbatt]

Well to put it simple, I wonder if there is a way to do this:

 

using bodyslide i can for example modify how "steel armor light" looks, this generates the file "cuirasslight_0.nif" ; this change will apply to all the steel armors of the game.

 

What if i want these changes to apply to ONE specific steel armor of the game, instead of all? I think it can't be done, so is there a mod that lets me create a whole new item for skyrim and use this .nif file to describe how it looks like?

[xkkmEl]

It cannot be done as you describe. Each mod defines its own items (kinds of items). Instances of these items can be created, and up to a point customized (name, enchantments, location) in game, via game play or script. You can't change the nif at the instance level though.

 

There are many mods that allow you to create generic instances of any item type you choose.

 

You could create a simple mini mod for yourself, with your customized item types.