CGTalk - Intersection problem with dynamic splines

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stevecullum

07-27-2007, 10:43 AM

I'm trying to make a dynamic cable animation using the hair modules dynamic spline tag. It seems to work really well, except where the cable crosses over itself - it intersects.

Is there anyway to add some kind of 'thickness' to the spline so there is an offset for when this happens?

LucentDreams

07-27-2007, 07:26 PM

in the dynamics there is a radius options you should always set that to the same radius as your sweeps.

stevecullum

07-27-2007, 11:43 PM

Thanks for your reply!

I have my radius set the same as the cable, but that seems to have more of an effect against collisions with other objects, in my case the floor. It doesn't appear to have any effect with self-collisions, unless I missed something?

I saw there are some xpresso nodes for hair objects, in particular hair intersection. Could there be a way to utilise this node? (I havent got any results with that, but I'm new to C4D and not totally sure how best to use it.)

What I have in the scene is a coil of cable, which then springs into life and locates the nearest amplifier for connection. It all happens quite quicky so the dynamic cable looks quite good flying about. Perhaps there is a work around - could I bake the point animation and adjust the keys manually?

Any suggestions are appreciated :)

LucentDreams

07-28-2007, 01:16 AM

are the segments part of a single spline object or are they separate spline objects?

You can cache the spline dynamics and then tweak frames. the challenge with spline dynamics unlike the regualr hair object is tha tyou have to turn the spline dynamics tag off while moving poitns, then click the UPDATE FRAME button, then turn the dynamics back on to scrub or go to another frame

stevecullum

07-28-2007, 11:10 AM

are the segments part of a single spline object or are they separate spline
objects?

The scene is just a single spline object, with a dynamics tag and thats under a sweep nurbs object and a small spline circle.

I'll have a go at manually tweaking and see how it looks. Someone else has suggested adding a clothilde tag to it. I'm not sure how to use that, but in Lightwave you can add a clothFX to the spline directly - but I couldnt get any results using the same approach in C4D.

Thanks again for your help :)

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