In this tutorial i`ll try to explain how to make a simple NURBS cylinder to behave like a real cable with gravity, some elasticity and all that real stuff. First i must apologies for my english. In this tutorial i`m assuming all the tools i`ll use are set to default settings.

I`ll make a new display layer (with visible tuned off), and i`ll put the cable geometry inside because i don`t need it now. I`ll build a simple NURBS curve, for this tutorial 3 spans will be enough. This curve will be use to deformation my cable. I`ll place the curve inside the cable. Now to be able to have full control over the curve deformation i`ll put every CV of the curve inside a cluster. I`ll select one CV at the time (very important) and bind it to a cluster. At the end of this "operation" my curve will have 6 clusters.

For this simulation i`ll use Maya`s dynamics system to deform the cable in a realistic way. i`ll build 4 little poly cubes and point-snap them to clusters.

The two clusters positioned at the cable ends will be controlled by two locators, locators which will be used for control and animation.

My dynamic cable is done, now let`s start tweaking the setting. First i`ll set the active rigid bodies by selecting all 4 cubes and using the channel box i set "Bounciness" to 0 and "Damping" to 2. Now it`s time to set the constrains. Select all 3 springs and using the same old channel box set "Spring Stiffness" to 70, and "Relative to" to Mid Point.

Let`s bind the two nail constrains to their respective locators, i`ll make use of expressions for that. I`ll select first nail constrain, in Channel Box i`ll make a right-lick on Translate X and choose Expressions from the pop up menu. In Expression Editor i`ll type "tx = locator_1.tx;" (locator_1 is the name of my locator). I`ll do the same thing for translate Y and Z with right changes :D. If i move my locator nail constrain will follow, that means i got what i wanted. I`ll do the same for my other nail constrain and his locator.

Hit the play button. When the springs loose all the energy (thanks to “Damping” attribute) i will have something like this.

First i`ll make a new layer (visible turned off) and put inside all the clusters, springs, nails, cubes and the gravity field, second i`ll make visible the layer which contain the curve and the cable. it`s time to bind the cable to the curve, for this i`ll use an wire deformer, following the help-line instruction i`ll select the cable first and press Enter key then i`ll select the curve and press Enter key again to complete the binding process. Now select the wire1 entry from the cable history list and set "Dropoff Distance" to 100. This will ensure that my cable will keep his volume.

My realistic cable is ready for animation. For that i`ll use my trustworthy locators. :D