Biped, mocap, and possibly crowd(?)

ScreaminBubba

I've been using biped and mocap data awhile now, and it works great for making game animations that usually are small loops and such that blend in-game for character animations.

I have yet however, to find a good workflow for using mocap data to build entire scenes, like a pre-rendered battle sequence, using existing biped animations that have already been made, similar to how a scripted movie in a game engine would show a cut scene. Something as simple(?) as having a looped walk cycle follow a spline path, for example.

Motion Flow's transitions tend to give me problems, and I cannot specify a path for a loop cycle to follow. It also usus the CoM for blending from one motion to another, 5 loops of a looped motion and your character is off in no man's land somewhere.

Motion mixer is nice, but again, I cannot specify a path for looped motions to follow (I'm not aware of a way at least)

I am not very familiar with crowd yet, and it seems useful for possibly doing this sort of thing.

If anyone has some tips on workflows they use for using game animations for pre-rendered sequences (of any kind), I would appreciate it.

Thanks in advance,

CrazyButcher

I am not familiar with crowd, but what you are asking for is something I always wanted to have too

basically one would need a script/plugin where the user defines which clips to play when, plus some sort of path (be it spline or manually set keys)

I will look into how much of CS is exposed in maxscript, but in general I think it will be some sort of "setup and compile" way, ie not dynamically modifyable. at least that could be done more easily I hope

another idea is (pure speculation so) adding some sort of expression to the biped root which "adds" the location transform ? so you setup the motions in the mixer, bake them, and then link biped root to some sort of path controller ?

Eric Chadwick

I haven't played with Crowd, but it looks like this is exactly what it's made to do. Well worth a read.

The one situation where we had to do a battle sequence with a bunch of running soldiers, they were all really far away and running the same basic direction, so we pre-rendered one loop of a solider running, then mapped the sequence onto a camera-aligned quad, then moved the quad across the field in time with his feet. Then we simply duplicated the heck out of that quad, offsetting the loop start time, and the position on the field. Worked great for that, and was really quick to render.
Movie here...
http://www.ericchadwick.com/portfolio/html/chadwick_mech3_cinematic.html
... it's the shot right after the binocular view. Can't see much in this low-res movie, but the original was 640 wide and the quads worked great.

CrazyButcher

cool idea, sorta like imposters, or good old sprites

anyway I looked into maxscript and I think I could script following:

you motion mix with their timings and all that and "output" the keyframes to regular bipedmode.
Then with the script select any object who the biped should be parented to, and the script will remove x,y movement of biped and use the one of the object. z will be "added" to the original (to keep up and down movement on runs..) and rotation will be as well "added" or overriden (not sure yet probably a checkbox for it)

it's weird that one cannot link a biped to another object, but this here would manually reset biped's root keys to match the objects movement (which you can animate however you want, spline...)

Eric Chadwick

I dunno man, not to discourage you from coding up a new tool, but I would check out Crowd first. Sounds like it already does this, and solves the foot-sliding issues. Better to try to use something that's battle-tested than go thru the rigormorale of a new tool...

ScreaminBubba

I had seen that mechwarrior movie before, very nice stuff.

I've made a few battle sequences in sort of the same fashion, stringing together a bunch of clips in motion mixer, then animating a root object in time with the feet.

I was able to use motion flow to create this scene: (12 meg file)
TrogBattleSample.mov

This was built from all the in-game motion clips to build an in-game story battle sequence, and pre-rendered for reference. It's sort of a hodge-podge, but it does work, I just didn't have the control I would like as far as where the characters ended up. It would be great to find a solution that uses motion accumulation to inherit its velocity per animation (accurately), this may just not exist for pre-rendered scene work(?)

[EDIT]
[CrazyButcher] Your idea sounds very cool, I just recently started learning maxscript, I bet that would be a bit of a pain to create, but if you would make use of it often it would probably be worth it.

[EricChadwick]
Crowd does seem to have alot of the functionality to do this sort of thing, and all behaviorly driven, which is nice for the flexibility. The help docs are decent for crowd, but I have managed to find very little additional info anywhere on the web. It's almost as if noone uses it much, it does take alot of preparation it seems to get a scene setup, I need to hunt down some good tutorials to get me started.

I appreciate the feedback guys.

CrazyButcher

I played with max7 on unverisity machines and the script I proposed shouldnt be hard to make, so I will give it a shot.
just hoping that under max5.1 I get equally good exposure of cs to maxscript.

crowd sounds better if you want less control and just masses behaving on their own (guided), my script will give you an exact path/object to follow. however you need the mixer to do the blends between anims yourself, also foot sliding and all that is up to you to be fixed.
anyway hopefully I will have something until tomorrow, now back to construction elements reading

Delaney King

I do this stuff a lot. If you make your bipeds run on the spot, you can pop the biped onto a dummy (I used a spline symbol so I can find each character in big crowds) and animate that along a path (I keyframe and use the edit trajectories sub object to pose it like a spline). If you take a measurement of the running and use a tape measure and snaps you can remove sliding.



A mate of mine was spawning orcs using particle flow, and they battled these little knights... waaaay cool.

Delaney King

oh yeah, you may want to turn your characters into a point cache so you dont have hundreds of bipeds running around. This has the bonus of being able to net-render without headaches. You could make these spawn by pflow too.. nice.

SideEffect

Hey sorry for bringing up an old topic. How do you go about doing that point cache thing Dave? I've recently gained intrest on this whole crowd simulation thing

Delaney King

Side effect... I will answer that in a new thread... check this forum!