The Elder Scrolls IV: Oblivion - Character Generation and Related Mods

Fantasy game art from The Elder Scrolls IV: Oblivion.

Probably the first thing to realize about the appearance of characters in Oblivion is that we are more bound by resources than in the real world.
By this, I do not mean just computer power, which directly affects such issues as how smooth curves can be or how nuanced textures can be presented. By "resources" we must also take into account available talent and time to prepare the necessary game elements. For each face and body type or "mesh", every item worn must be fitted so that they will display properly in-game. If there are too many substantially different meshes, clearly the work starts to multiply very quickly.



In the picture of the sleeping gladiator above, you can see an example of "clipping" that can inadvertently occur when different objects in the game: For the most part her armour fits tightly enough around her body to look properly worn, but if you look carefully at the belt near her bellybutton you will notice that some allowance was made to ensure her body doesn't end up occupying the same space as her belt.
Something that could happen as a result of two meshes colliding is visible in the lower left corner, where her fingers have poked through her shield. In any case, these issues are so minor as to mostly be overlooked in the course of normal gameplay, and it is generally not useful to exhaustively test every situation.

Faced with the issue of limited resources, it is not surprising that for the most part, meshes are re-used whenever possible, and differences made up with textures.
You can think of meshes and textures as a parcel providing the "mesh" over which wrapping paper tightly wraps. Instead of changing the box, we can try to fool the visual senses to seeing contours and textures by choosing the wrapper. Or, we can make changes to the mesh that can simply be recalculated instead of actually having an entirely new mesh. So, for example, if you consider the pictures below of a younger and older woman, and focus on the outline of the face instead of the face itself, you will notice that it is essentially the same shape.

The consequence of using stock body parts, however, is that some parts don't go along with others. For example, a generic adult body doesn't necessarily fit every face. Maybe it will do for youthful 20-somethings and fit 30-somethings, and maybe hot 40-somethings, but only once the character in question is 50-something or has a worn, haggard look, then the stock body will simply look out of place. Spellforce 2 suffered from this, where every woman, young or old, had an athletic build and firm, gravity-defying D-cups -- as illustrated in the picture on the right, of a grey-haired elderly woman in armour.

Buxomness isn't emphasized in Oblivion, so an acceptable solution was found in demurely clothing everyone and pants, long dresses, and sleeves abound. Mods such as Colourwheels Sexy Oblivion Overhaul show off a lot of skin, and the result looks anywhere from odd to disturbing on such characters as old beggars. If you want a perfect world where every woman has a hot body and well-endowed chests, then combine Colourwheel's mod with the Hentai Gentlemen's EyeCandy Body, commonly known as HGEC. For male characters, Robert's Male Body Replacer is the standard.