Matt's been responding to questions about the E3 Halo trailer in a couple of threads at halo.bungie.org. On the subject of why there was relatively little blood and gore shown, he said:
Given America's current socio-political climate, where talking head pundits who've never played a computer game in their lives blather endlessly about their destructive qualities, and the negligent parents who never question anything the TV says snivel in unison that the government isn't doing enough to control the games they buy for their own kids, it would probably be a bad idea to show up at E3 with a movie emphasizing the realism of our virtual blood.And now, the professional, non-hostile reason:
The primary goal of that E3 movie was to dramatize what gameplay would be like. All the slick technology was put in service of that substance-over-style goal. We'd already done one trailer that made people ooh and ahh, but people were wondering what gameplay would be like; we knew we wouldn't have a good, solid, playable build for E3 but we wanted to give people a taste of that. If we'd just wanted to do another engine demo the programmers and artists would have worked on other stuff and the whole thing would have been markedly different, with even more eye candy. My point being: things that were not as refined in that movie as they could have been will change for the better before release.
And concerning IK and the question of whether the deaths in the trailer used it:
IK is basically the process through which a character's body reacts appropriately to environmental constraints. The position of a player's hands on the jeep's steering wheel, for example, or the player's hands taking the appropriate position on a gun. Presently it's a subtle effect; you don't play Halo and shout Dude, check out that IK! Well, obviously YOU don't...but even those of us with access to builds don't. ;-)Work has been done on applying IK to player deaths but none of it has made it into a build yet. So those of you who dissed the deaths in the E3 trailer can chill. ;-)
Check out the two threads.