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Gordonpee
09-29-2005, 06:58 AM
I'm looking for some clues on being able to unwind a hose with soft body dynamics.
I'm hoping to be able to keyframe the tip of the hose and either pull it and hose pulls off a reel spindle(that would rotate), or the reel spindle rotates and the hose uncoils off.
Does anybody have any hints at this?
Thanks,
Gordon

Celshader
09-29-2005, 07:36 AM
I'm looking for some clues on being able to unwind a hose with soft body dynamics.
I'm hoping to be able to keyframe the tip of the hose and either pull it and hose pulls off a reel spindle(that would rotate), or the reel spindle rotates and the hose uncoils off.
Does anybody have any hints at this?
Thanks,
Gordon

I haven't experimented yet, but here's some of my initial thoughts...

For a hose, I'd use a stand-in ribbon to calculate the dynamics. That reduces the risk of the hose collapsing in on itself like a windsock. ClothFX also has a "StartByEvent" feature that could come in handy -- use an Event-type collision object to make dynamics happen only on the unwound part of the hose, and not on the reel itself.

If a coiled stand-in ribbon doesn't "MetaLink" too well on a coiled hose (because all the points would be so close together that anybody could belong to anybody), then use a straight stand-in ribbon on a straight hose (to make everything perfectly clear to MetaLink). Then use a morph target to coil the stand-in ribbon as a "starting point."

If the coiled ribbon tries too hard to maintain its coiled shape while being unwound, turn off "Relax Start" so that it treats its uncoiled state in Modeler as the "true" state of the object, instead of the coiled state at the beginning of the calculation.

Another way to deal with this is to have the uncoiled section of hose emerge from the underside of the coil, instead of the top of the coil. Use clip maps to hide more and more of the coiled hose and reveal more and more of the emerging hose as the rotating coil "unwinds." Apply dynamics only to the emerging-hose object, and you won't have to worry about "StartByEvent" at all.

I hope this post helps. Since I have not yet experimented with this myself, I do not know if any of the above tips are worthwhile.

MonroePoteet
09-29-2005, 06:43 PM
If soft dynamics doesn't work for you, you might also try a variation on this tutorial:

ftp://ftp.newtek.com/pub/LightWave/Tutorials/Vidz/property_web.mov

Here's a sample scene. The amount of hose coiled on the spool is controlled with the relative percentage of the hose morphs in Morph Mixer rather than keyframed on the hose itself.

mTp