PDA

View Full Version : Breaking Dynamics



gschrick
10-25-2011, 07:33 AM
Seems silly, but all I am trying to do is drop a candy corn on to a floor and have it bounce/roll a little and stop. When I can actually work without LW crashing on me, the candy corn (hard FX) hits the floor (collision) and continues to bounces forever, actually increasing it's bounce height.

That and everything is in slow motion. I created the candy corn to it's realistic size. I've tried Stop by stabilizer, but I can only use that if I say "start by event" and then the candy corn won't fall with gravity.

And like I said, LW can't seem to do a calculation more than 3 times before it just gives up. And I'm calculating a whopping 325 polys.

I'm not a novice LW user, although I don't use dynamics as much as I'd like. BUt it seems like I should be able to easily tell my objects to come to a stop.

10-25-2011, 07:53 AM
I may be old & bitter & twisted, but whatever happened to animation as a skill? real world has so many variations of surface & other factors that although playing with dynamic simulation is enormous fun, & pretty usefull for soft bodies, surely just animating a couple of bounces with keyframes is going to get something much more believable much quicker !
I've been able to scatter dozens of particle objects & bounce & slither them to a stop, but never got anything remotely believable on a single object under close scrutiny!

gschrick
10-25-2011, 08:04 AM
Yes, if I was only going to drop the single candy corn, I would hand animate it as I have done so many times in the past. But I will eventually drop many, cloned from the original once I have the settings right. I don't have the time to keyframe that many, nor do I have the time to constantly change the dynamics settings on multiple objects.

And if the TV station I work for actually gave me more than a few days to complete an animation, I would love to spend it personally animating each object.

Sorry I wasn't as informative in my original post. Regardless of how I am animating the object, how to I tell it to come to a stop?

mummyman
10-25-2011, 08:23 AM
Isn't there a "stop by stabilizer" somewhere...collision menu in Hard FX? It's been a while.... can't test it now though.

xxiii
10-25-2011, 12:21 PM
I may be old & bitter & twisted, but whatever happened to animation as a skill? real world has so many variations of surface & other factors that although playing with dynamic simulation is enormous fun, & pretty usefull for soft bodies, surely just animating a couple of bounces with keyframes is going to get something much more believable much quicker !
I've been able to scatter dozens of particle objects & bounce & slither them to a stop, but never got anything remotely believable on a single object under close scrutiny!

I would just like to point out that with properly working dynamics, you should be able to get something perfectly realistic, fast. I said realistic rather than believable because hollywood has conditioned audiences to expect people to be able to leap off of 4-story buildings and continue a foot chase without so much as a bruise. (They might limp for 100 or 150 frames, but then it will be gone).

However, I love the "roadrunner" (http://www.youtube.com/watch?v=_S47e6YFhCo&feature=related) episode of Farscape, and that most Pixar movies include wording to the effect of "Made with genuine animation, no motion capture" in the credits.

erikals
10-25-2011, 03:43 PM
still, probably made with plenty of video reference though... ;]

(just like every disney movie...)

gschrick
10-26-2011, 05:50 AM
I tried "stop by stabilizer". But I can only edit it if I choose start by event of collision. I want it to start by gravity, to fall naturally. When I do add a value in to the Breaking distance and make the objects fall there is no effect to the objects momentum after impact. I've tried values from the mm to meters and there's not variation in the movement.

xxiii
10-26-2011, 07:36 PM
Its been a while since I've messed with this (having given up on the current dynamics implementation) but you should be able to dampen it, and it will just stop naturally.

Perhaps the resistance setting in HardFX and the bounce/bind power in FX Collision, which I noticed defaults to 200% when I added one just now, which might be why your candy corn is bouncing funny. Friction may also be involved. There are also the effects of wind resistance (which are probably negligible in this case).

gschrick
10-27-2011, 06:41 AM
I lowered the bounce/bind power and tried numourous settings. Either the candy corn bounces into the stratosphere or they hit the ground and stick (even with the collision set to bounce). The sad part is when I get the initial bounce somewhat right, the candy corns continue to bounce more than I want and actually start bouncing higher as if on a trampoline.

I finally gave up and made an animation with a Ouija board. Ran out of time to figure this out.

erikals
10-27-2011, 09:50 AM
hi, try animating the bounce/bind power... (via the envelope)

xxiii
10-27-2011, 04:56 PM
I think there is a weight/mass setting somewhere also that might affect it, although that should only be important on momentum transfer, friction, and wind resistance (although the bounce involves a momentum transfer; which I highly suspect FX Collision does not handle correctly).

But, Ouija boards being more reliable, is why I find the current dynamics implementation frustrating. The real problems show up when you get beyond trivial interactions.