It actually does happen on occasion, however for some reason the devs set it extremely low. To fix it and have characters bloody up their swords and themselves open your Oblivion.ini file (under My Documents/My Games/Oblivion/) and look for these two lines:
fDecalLifetime= #
iMaxDecalsPerFrame= #
Defaults should be set to 10 for DecalLifetime and something like 30 or some insanely low number for MaxDecals. The first setting sets how long decals (blood for instance) stick around after they are shown to the player, and the second sets how many decals are possible in the frame at once. Since the decal lifetime pretty much cancels out ever being about to see more than like 50 decals at once, you should be able to safely turn it up. I cranked them up to:
fDecalLifetime=20.0000
iMaxDecalsPerFrame=1000.0000
I see blood ALL the time now all over my sword, sword swinging arm, enemies, etc, and it´s hardly detrimental to my performance. Tweak it to your liking. And happy slaying!
voila voila , je crois que c´est la bonne solution j´essay et je reposte