Cel Shading is possible in UT3ed but I don't believe it can simply be applied as a post process, and even if it could I don't think it would give good results.
Cel Shading is complicated. In fact its the most complicated example over on Hourences tutorial site. Scroll down to the bottom and have a look at whats involved in cel shading
I doubt many mod authors are going to want to tackle cel shading their entire project. I'm sure someone will eventually, but it looks like a pain to me.
A post process would make it easy, but I just don't see how it could be done.
I doubt a post processing option would be possible, but that comes from someone who has yet to figure out what post processing actually does in UT3.
On a side note, team Fortress 2 is not cel shaded.
It's vibrant, colourful, and the characters have a very cartoonish look about them, but it's rendered in 3D 'normally' as opposed to cel shading's pseudo-2D look.
Although best of luck to you, I'd very much like to see what the outcome looks like and may even play it frequently.
Keep in mind however that re-skinning models may be necessary too.
UT3 has a lot of detail and high resolution fine detail, such as face stubble and intricate armour patterns, along with high polycount models with lots of curvy bits and ins and outs.
Cel shading looks better with low polycount, or at least smooth models combined with simple one or two colour textures.
If the current textures used on say the lead character on campaign mode for example were used in a cel shaded render, it would look quite messy and parts would be hard to make out - plus the ins, outs, holes etc in the armour would all get a black line drawn onn them as is normal for cel shading to outline important 3 dimensional detail - which could cause it to look even more out of place as lines would almost cover a lot of the models from being seen.
While it would work, it would probably be better doing cel shading on UT2004, or even UT99's dmodel detail.. At least if it was intended to be playable, and not just for educational purposes only.
Yeah Fyrbunr... I guess you are right but i have no intentions of using the stock models and mats etc... if I would go cell shading then i would have to create some new characters in low poly as you say.
Well now i know that it is possible, my ideas are not for a cell shaded shoot really he mod would be something else entierly but a small test as a shoot is a must if i atempt to do this..
anyways thx for you help, if you find any other tutorials for cel shaded rendering for the unreal engine 3 (or unreal ed 3) post em here...