View Full Version : how to add dynamic cables?

07-13-2008, 05:36 AM
Im building an excavator and have now ran into an expected problem..as i have no experience with dynamics.

I wish to have a cable that follows the shape of the crane as it moves...i understand that cloth could be part of the solution, together with collision objects..but how to attach it to fixed positions of the excavators mechanism?

see pictures for explanation..the red stripe is where i wish to have the cable.

07-13-2008, 06:26 AM
2 ways, depending on your situation.
if cables move but don't flex (ie, they stay taught) then a UV map with textures driven by a null that can be linked to the rotation channel of the lower arm (arm up = null moves towards can and moves texture down cable and the opposite)

Other is IKB on the cable which will give the cable a flexing motion.

A combination of the 2 will make a flexing and moving cable.

07-13-2008, 06:52 AM
IKB seems to be what im looking for..any suggestions on how to apply it on this scene?

the idea is to get the cables to interact with the movement of the crane..not to go through the object at any place and to be as automated as possible, meaning that i simply focus on the movement of the crane for animation and the cables should preferably do their stuff without detail involment from me..

ive managed to get the hydraulic pistons to do it automaticly...but the cables seem much more difficult since they are to be a one piece object that needs to bend accordingly to the movement of the crane.

07-13-2008, 07:01 AM
bone dynamics (collision) will keep the cable from going thru object (it's an extremely fast calculation).
As for keeping the cable taught...haven't gotten that far in IKB yet, but I would suppose offhand from what I've seen from various IKB vids, that a channel follower added to IKB bones that would stretch bones depending on the position of lower arm is way to go.
Splinegod would know for sure...he's the resident IKB expert.

07-13-2008, 07:41 AM
I myself would use a chain of quad polys which represent the cable, then parent the cable to it. Use Cloth dynamics on the quad polys, with points at each end made into a selection set which is set as the 'Fixed' set in ClothFX. If you apply Metalink to the cable object, it will follow the motion of the quad polys. I'll knock you up an example scene.

07-13-2008, 08:47 AM
Here's the scene.

07-13-2008, 09:07 AM
Heres a very simple way to do it and doesnt require dynamics plus
you can do a load from scene and attach youre hoses wherever.

07-13-2008, 09:21 AM
Thanks guys..ill check the scenes when i get home again.