Change Unit Skin?

Can anyone help me in creating a jass script that would change the chosen unit's skin to another (any texture) temporary - just for targeted unit, not the whole unit-type.

A'm making a spell, it's like Avatar - when it's cast the mountain king changes skin to stonelike - but I want this to be offensive ability.
I know it is possible to change unit's size, coloring, animation speed vie triggers, but not used skins - and still some blizzard abilities can change unit's skin (Avatar) or even model (Demon Hunter's Metamorph).

Can someone help me with this, please?

No.

Griffens not saying No as in were not helping you.
He means theirs no solution, which their isent.
You cant change a units skin ingame.
You can only change it before the map is played. (I mean when editing).

It is possible in some cases.
In the case of a Tauren Chieftain or as I assume you wanted, a Mountain King.

There are two skins for the Avatar MK and then the normal MK.
Just import whatever you want the special skin to be over the avatar one, and keep the normal MK however you wanted him to be.

And I would be interested in how blizzard made Avatar ability. There must be a way to do the same in jass, because I want this to happen when cast on enemy. And it is not possible to do it with Avatar.
But if I was able to look into a script where original Avatar is made for example, (I mean the script telling exactly what happens, what functions are called when Avatar or another ability is cast) I could altern it so it would happen when cast on enemy.
And also would help me if I know where can I find functions defined - in Blizzard.j and common.j there are only declarations, and again I don't know what happens when function SetUnitScale (Change Unit's Size in trigger editor) is called. It must somehow access object's data (maybe like collision size) and change it.
Can I access these scripts?

Thanks for help anyhow.

Set unit vexter coloring to all zeros.
AND create other unit with other skin on same place with original unit.

Avatar dosent replace skins, it replaces models, their are 2 models for the mountain king in Wc3.
He playes his Morph Alternate animation when the spell is cast, then the models are switched.

Sorry to go slightly offtopic, but if you have ever played "Zeus", in a game of Dota, he has the other model, not the normal mountain king model.

Functions are defined in blizzard.j
Natives are defined in common.j

You cant edit spells, as they are in a different file and probally dont use Jass.

There is not a separate MK model for normal and avatar. The MK model just has a set of 'alternate' animations, same as every other morphing unit.

... and alternate skin, I know there are 2 skins for mountain king, when avatar is used by another unit, i just growths, streghtens, ... but has no other skin like MK. So it doesn't change it.
And as far as I know there is only 1 model of Mountain King. And the in model editor you see that weather you chose 'alternate' animations or not, it still uses the stone skin.

If you look at the normal mountain king, it dosent have any alternate animations but the transformation one, im positive their is a seperate model.

The MK unit does indeed have a set of alternate animations, a seperate mesh is used with a material that uses another texture. The alternate anims toggle the mesh visibility so that the other mesh is shown.
Possible solutions:

• Have another unit to copy the other unit' movements (as DioD said)
• Create a custom model for each unit that is supposed to have the alternate skin.
• Use destructables with the changable ReplaceableTexture (not sure about this one)
• Use hex/polymorph if you dont need the unit to use abilities/attacks.

The mountain king has only one mesh. It uses a material with two main skin layers; one for each. All that happens is that these layers swap for the alternate animations.

The alternate animations cannot be seen in the editor because they are labelled "Alternate Stand" etc instead of "Stand Alternate" etc.

well, thanks for help, but what exactly I want is:
I want an ability which when is cast on enemy unit, it makes it into stone statue, immobile, uncontrolable until the spell is dispelled, but not by expiration timer.
I have a good stone skin that can be applied to any unit making it look like statue.

I can do everything with triggers (set unit's animation speed to 0, pause unit, ...), but I cannot make the skin aplly on unit. I found it is possible to altern some things in object editor, the script I want is similar to 'change unit's size' or 'change unit's animation speed', just temporary, the unit would remember it's original skin, but would show the stone-like.

Don't know but this might be of use: http://www.wc3campaigns.net/showthread.php?t=52227