Suitable software for modelling and animating?

[Benjamin]

Obviously I'd like it to be something that can export to a supported UE format (unless a converter is also mentioned), preferably something free, and with capabilities to produce compatible animations.

Any ideas? It's just for altering existing weapons really, and maybe tweaking animations a little.

[edit] I've done some searching and found a couple of other threads about modelling programs for KF:

http://forums.tripwireinteractive.co...ad.php?t=41355
http://forums.tripwireinteractive.co...ad.php?t=32876