View Full Version : Another newbie conundrum

06-28-2007, 05:56 PM
Heh, I should almost start a new LW Blog, called the Lightwave Newbie Conundrum of the Week :)

I'm trying to logically figure out how to create a coaxial cable that extrudes out of a wall socket, interact with a live action person by having the connector end look at the person and then like a constrictor, begins to wrap him up coiling quickly over his legs up his body. Back when I was in Softimage (pre-XSI) this would be achieved by "Extruding over time" using a spline as a guide for the cable's deformation but I haven't the foggiest idea how to achieve this in LW3D.

Thankfully the shot is broken into different cuts at different angles so some of it could be taken care of by using a subdivided cable and some IK Booster.

Any insight on this would be very helpful :) Thank you!


06-28-2007, 09:41 PM
Is the person going to be struggling? This would add a lot of complication to the shot. :)

06-29-2007, 11:34 AM
yes, not too much (legs will be bound together and a bit of wiggling) but it would be relatively trackable. If time were tight I would animate the cable in Lightwave 3D and then use After Effect's distortion tools to make it match the talent's motions. It makes me wish we had CS3 already since the puppet tool would be right up this alley.


Steve Warner
06-29-2007, 12:14 PM
A couple of ideas here:

1. The Shift Spline Transform plug-in will allow you to animate an object along a spline path. You could use this to "grow" the cable out of the wall and wrap it around the legs of a character. I've used this at work to show BNC cables connecting to various ports on a patch panel.

2. The Fertilizer plug-in can grow objects based on a weight map. You can use it to grow the cable into its final shape. Do a search on Flay for Fertilizer and you'll see what I mean.

3. The IK Booster tool is ideal for long bone chains. It would be a bit more work than using the plug-ins above, but you should be able to animate the cable with a high degree of control.

06-29-2007, 01:59 PM
Thanks. Another idea that just popped into my head on how I could make this work is by making the BNC connector an emitter and having it "emit" a cable textured hypervoxel along it's motion path making it look like it's growing out of the wall.

The trick is theoretically when you have a close up of the person getting his legs wrapped around. Won't the voxels try to blend with the next string as it coils around the legs unless a wide enough gap is maintained?


06-29-2007, 06:45 PM
The shift spline transforms a good idea because you have nodes to animate the spline.The nodes can be parented to bones in parts of the character so the object can move along the spline and be deformed as the character struggles at the same time.

FIs bezier bend might also work in a similar fashion.

You can also create a spline in modeler that generally conforms to your character. The spline can be converted to a chain of skelegons which can be converted to bones. The cable can be morphed along the bone chain. IK boost can be applied to the bones to give you some ability to move the bone chain somewhat.

Another option would be to use DStorms Trailer plugin.

07-02-2007, 12:09 PM
I'll give that shift spline transform trick a go at it. I've never used it before so I'm sure it will need some finessing. I'm guessing I just have to supply a large amount of polygons in modeler so that when they are subdivided it will smoothly animate along the spline? Unless this allows you to create polygons as it animates along like a rail extrude?

My boss decided to take this particular shot out of house so I would be available to work on other aspects of the commercial so the heat is off timewise. I still want to know how to do this beast so if I get a free moment this holiday week (which looks plausible) I'm going to give this sucker a whack since we have the footage shot already for the leg binding.

Thanks for the insight, now to learn :)