What about the key frame blending?

[marksmanHL2 :)]

I do know gorgon. I was just being restrained thats all.

 

[Mountain Man]

Thanks, stigmata! That was a very thorough and understandable explanation! Still doesn't explain why we've not seen any examples of ragdoll blending in the gameplay movies, but at least now I understand the technology a little better.

 

[dscowboy]

Originally posted by Mountain Man
Still doesn't explain why we've not seen any examples of ragdoll blending in the gameplay movies

See my post. When Ken said 'blending' he was referring to the real-time generation of a specific type of animation, not the blending of ragdoll (FD) anim with keyframed "victim keeps walking" or "victim grabs his knee" animation.

 

[Mountain Man]

My point is, we haven't seen evidence of enemies reacting to getting hit by bullets other than suddenly dropping to the ground. My question is, why?

 

[Stigmata]

NP Mountain Man, dscowboy did a better job of explaining but its good to see someone take notice of me

There are some examples of animation blending. Only one so far is obvious to me, and that is with the Strider. It's not really blending per se, since it doesn't animate a part of its body with 2 animation types at a time. But the Strider is an example of a character that uses IK in one part and FD in another. The legs use IK, and if you look carefully the giant gun under the body swings back and forth as the Strider movies, therefore using FD (ragdoll) animation.

Aside from that, the first Combine in the Traptown video seemed to blend IK and FK, as it seemed to react to being shot a few times.

EDIT: The answer to your other question, Mountain Man, is most likely this: "It's a design decision, not a technical limitation."

 

[dscowboy]

Mountain Man, I don't think Ken mentions blending between two different animation types, when he says blending he's not referring to that. But I think Stigmata is right, the Combine at the beginning of traptown does blend a gun-firing animation with a i'm-getting-shot animation.

Stigmata, I noticed the same thing about the Strider, I love how the gun flops around as it moves. The animation they've done on the Strider is incredible, the way it can pick its way through varied terrain, duck under obstacles, pick targets without having to turn and face them, all very cool. Like you said, it looks like the leg movements are IK. They couldn't be ID because the strider would've fallen over when it stabbed the resistance fighter otherwise. Too bad tho... a completley ID/FD strider would be fun to trip. :cheese:

 

[Stigmata]

Just because the Strider can stab a guy w/out falling over, doesn't necessarily mean it doesnt use ID. I think when an arm or something using ID hits an object, it applies force to the object as opposed to stopping in its tracks. This way the Strider can still adequately disembowel humans but can also be tripped.

 

[Ro@cH]

Great explanations you two (stigmata and dscowboy) and also great discussion. I've been bookmarking pages with explanations of techniques used in games (both graphical techniques like bump mapping etc, but also animation techniques). This is another one that's going to be added to my collection. *bookmarks*
Thank you!

About the movie: I love the way all the enemies get blown away down the street by the grenade explosion, together with all the wooden boxes etc. Looks so great Indeed: physics is cool.

Mental note: I have to show Havok to my grandpa (no kidding), he's greatly interested in the theoretical stuff (physics, maths, kinetics, etc) and he'll be amazed by some of the interactive demo's on the Havok website.

 

[dscowboy]

Originally posted by stigmata
Just because the Strider can stab a guy w/out falling over, doesn't necessarily mean it doesnt use ID. I think when an arm or something using ID hits an object, it applies force to the object as opposed to stopping in its tracks. This way the Strider can still adequately disembowel humans but can also be tripped.

Stigmata, what I meant was, if the whole Strider was dynamic (FD or ID), there's no way it could balance on two legs without falling over. It's a tripod and it was standing still, so when it picked up a leg to stab the guy it should've tipped over. Right?

 

[koopa]

Originally posted by dscowboy
Stigmata, what I meant was, if the whole Strider was dynamic (FD or ID), there's no way it could balance on two legs without falling over. It's a tripod and it was standing still, so when it picked up a leg to stab the guy it should've tipped over. Right?

There's no reason it can't be stable on 2 legs - perhaps the Strider has the ability to move its own centre of gravity around. It's got some kind of big ballast thingy in its head maybe. That would be cool.

 

[dscowboy]

Originally posted by koopa
There's no reason it can't be stable on 2 legs

If your center of gravity is not within your base, you will fall over. Try making a tripod out of three sticks, then take one of the sticks away. It will fall over. Similarly, a Strider who is standing still, balanced on a tripod of three legs and who subsequently lifts a leg off the ground would no longer be balanced.

I don't really care whether the Strider falls over or not, I'm trying to figure out how it's animated. I think the fact that it doesn't fall over proves that the Strider is not fully, physically dynamic.

 

[Stigmata]

It could (probably) easily be a dynamic blend of FD (most of the Strider) and IK or FK (the stabbing leg).

 

[supangr]

Originally posted by Mountain Man
My point is, we haven't seen evidence of enemies reacting to getting hit by bullets other than suddenly dropping to the ground. My question is, why?

The first combine in traptown seems to jerk his head back when he gets shot with Gordon's pistol. Too brief to tell if it's physically simulated or just a static animations that's always played out the same way though.