Dr Pixel's Bodyshop Mechanic
This is NOT a tutorial, just my notes on Sims 2 skins in the hopes it may help someone understand a little more. There are lots of excellent tutorials out there on shading, meshing etc, and as I find more I will link to them in my Tutorial Links section.
To get Body Shop fullscreen there is a hotkey - Alt and Enter!
How Skins work
How meshes work
Conventions for filenaming of skins
Changing the background in Bodyshop
Showerproof Skintones for different bodyshapes
External Tutorial - converting outfits between bodyshapes differently shaped skin - great visual tut by Gothplague.
To export a Sim for upload
Sims 2 skins are very like Sims 1 skins; they are a 3-dimensional representation of a skin but produced using mostly 2-dimensional tools.
The only thing that is really 3-D is the mesh. Let's have a look inside the skin files.
Think of a mesh as the "wireframe" of a Sims' outfit, upon which you hang the fabric texture you make in Body Shop.
Here to demonstrate is a Sim wearing a completely white version of what I call the "dressing-gown" formal. That shows the shape of the mesh. Notice that if you make the texture transparent, the underlying texture of the Sim's nude skin shows through - with some very strange results. She has no legs - and the front view is even stranger.
This is why you cannot make a skirt shorter, for example, by simply chopping off some of the alpha channel.
You need special 3D applications to edit or even view the mesh, and as I have not done this I cannot recommend any.
Remember we said the alpha channel is the file that controls transparency? The basic idea here is that whatever is darker in this file, is more transparent, So you can make clothes with deeper necklines, cut-outs, etc, by adding their black shapes within the alpha file. This particular style doesn't really lend itself to that kind of interpretation. I've seen some very pretty evening wear made using varying degrees of transparency; this tends to look more natural if your Sims have anatomically correct nude skins.
To make your own proper nude skin that may be selected as eg formal clothing, like my Not-Skins in the Adult section.
Export the skin you want to use from Body Shop. A close-fitting swimsuit type outfit. Find the black and white alpha file. You will see the shape of the clothes as pure white. Make all that graphic fully black. Refresh the view in Body Shop. You should be able to see the Sim's skin (in Bodyshop unless you have Targa's mod, you may well see her in her undies). Reimport, selecting the Formal category. Voilą your invisible clothes, revealing the skin beneath.
If you have a Sim who is, say a robot or a cat, and may not want to wear clothes, you can use this mesh - as long as the Sim is shaped like a normal Sim - it will not solve the problem of tails, etc.
These are helpful when you are making nude, alien, cat-people, etc, skins.
B = baby
P = toddler
C = child
T = teen
A = adult
E = elder
Make your background image 1024x768 BMP, you have to name it userbkg.bmp and it goes
in My Documents\EA Games\The Sims 2
Open Bodyshop, press F5 to toggle it on and off
F3 brings the view to very close.
http://www.insimadult.net/showthread.php?t=26228&highlight=floating+head excellent tutorial by Beosboxboy (warning: adult site)
True nude state for Sims 2 Sims uses two meshes, a top and a bottom, for upper and lower body.
Shower-proof skin tones retain a custom mesh's body shape in the true nude state, ie in shower, the bath tub, and sometimes hot tub, and if your Sim doesn't then the following things MAY fix it.
If she reverts to Maxis normal shape, the skintone is not showerproof, that is, doesn't call the special body meshes.
If her body disappears in the shower giving the notorious "floating head" syndrome, this usually means the appropriate mesh is not installed.
Once made in Bodyshop the Sim will appear in the SavedSims folder as a .package file. From there it can be moved, distributed etc. Note that after Pets it WILL contain any custom content used in that Sim.