View Full Version : Unsprung Hero

08-14-2006, 10:42 PM
I'm about to give up and just fix this in post, but I figured I'd toss this one out there for some other ideas. I am animating a medical device that has a tightly wound spring. When the device is inserted (I won't bother to tell you where cause you would lose sleep) the spring unwinds. So when viewed from the side, in the wound position, there are 60 or so loops to the spring, and when unwound, there are 25 loops. The spring gets shorter and bigger as it unwinds so that it can fill the hole its been inserted in. Yuck.
--Endomorphs don't work, they self collide during the transition.
--Sipmly stretching the spring does not work because it has to maintain a realistic volume and shape.
--A 2 point poly chain with Soft FX and FX Link is good for resizing, but does nothing for the unwinding bit.
To the person who provides a workable solution, I will mail you the device as a keepsake. It has not been inserted into any body that I know of.

08-14-2006, 11:28 PM
There was some way to do something like this with wieghtmaps I believe... something to do with using UVs to generate a weightmap.

Lemee see if I can find it.

*10 mins later*



there we go... the tute only covers compression of the spring, but I think the uncoiling you describe could be done...

08-14-2006, 11:36 PM
Try a combination of a Twist deformer, and scale the spring to make it fat and short as you unwind it?

08-15-2006, 04:05 PM
James, I tried the twist deform in Layout, but unfortunatly,it changes the size of the loops, which is a no no. I can see some other uses for it though. Any other ideas?

08-15-2006, 04:20 PM
Loki74, that was a good link, I will be sure to incorporate that tool in the future, but I'm afarid that it does not help at this point, unless of course I'm just not seeing the connection. I will keep trying. This might be one of those things that Lightwave just can't do. We shall see.


P.S., I have attached a few pics of the object in question

08-15-2006, 04:35 PM
Is that one of those things for widening an artery that's been bunged up with plaque?

I had a hot-dog today. My question is pertinant. ;)

*edit* You could almost certainly handle that with morphs, as long as you used a few stages, rather than just a Start and End. Does the coil "move along it's length" as it animates? If it does, then you could probably do it with an animated texture, if having actual honest-to-gh0d thickness to the spring wasn't important.

*thinketty* Hmm. Good one! I'll have a ponder.

08-15-2006, 04:56 PM
No, this device is for women, and it goes in a little south of the heart.

Yes, I have two morph targets, tried a in between target as well, but did not work correctly.

The coil unwindes, gets larger and shorter as it fills the "Hole" the doctor put it in. But the individual loops of the spring remain a constant size.

As it turns out, it was the hotdog that caused all the problems in the first place.

Here is the object, if you want to try it your self.


08-15-2006, 05:13 PM
Not 100% sure what your after, but think that a combination of endomorphs and displacements should work.. check out Splinegods endo tutes (http://www.3dtrainingonline.com/displacements2.htm)...


08-15-2006, 05:23 PM
Oohhhh, riiiiight.

It's a belly-button scrubber.

I'll have a fiddle over the next day or so - past midnight here, so I'll have a play tomorrow.

*edit* I can see how to do it with a midpoint morph, I'm just too darn tired right now. Get it to you tomorrow...

08-16-2006, 08:50 AM
RichDJ, I have purchased SplineGods Tutorial and am in communication with him, he has provided a solution that is based on an effector and a 2 point poly chain, but I need to have greater controll of the models shape during and after transformation. I'm so close, yet so far. Perhaps a beer will clear my head. I will keep you posted.

08-16-2006, 03:35 PM
Cool, looking forward to seeing this done..