Rigging this cable and tray:

[J450NP13]

I am having a hard time understanding how I can rig this cable and cable tray for a Genie man lift.

The arrow is the direction the tray goes and the cable will follow it.  I have tried a few different things....using joints...a curve with a curve warp....I cannot get anything to work.  A lot of searches took me to animating it on a curve with a motion path...but I feel like that isn't the way I would do it.  I was also thinking maybe using dynamics to do it but then would get some unwanted effects.

The arrow is pointing in the direction the boom arms will extend which will pull the cable in the same direction along with the tray.

Any ideas?

[mcw0]

A bit confused with your image.  A genie man lift is a 3 jointed system with an extendable last section, right?  Where is that in your image?  And is the issue how to rig the cable that spans those 3 sections?

[J450NP13]

Not 3 joints, they extend out like a crane.  And yes...how to rig the cable and cable tray to go up with the extended boom arms.

At 16:50 you'll see it.

https://www.youtube.com/watch?v=murzdJ8m1DY

[mcw0]

Here's a quick proof of concept.

Start with straight curves and a half circle. Because Maya doesn't rebuild curves correctly, I generate nurbs surfaces from these curves by first creating offset curves and lofting. Now extract a curve from the nurbs surface. But since the surface will be changing when animated, you have to rebuild the surface to reparameterize the extracted curve from 0:1. Now you can use this curve as a motion path. Notice how the length of the curve stays pretty constant as well as the offset distance of the test locator (beginning of your chain) from the end of the curve.

I tried to attach my .mb file but I couldn't.  😞

I just tried to upload the .mb file and it just won't do it.  Sorry.  If anyone knows how to upload .mb files, let me know.

[mcw0]

Trying as zip

Well that worked.  Let me know if you have any questions

[J450NP13]

I will check this out later this evening. Your video looks exactly like what I need it to look like.

Thank you for taking the time to do this @mcw0

[J450NP13]

@mcw0 

This looks like what I need it to look like but how can use these tray links like this?  When the boom extends out these links will follow that arm its connected to until it is to its max extension.

Also, I will be using "Set Driven Keys" to extend the booms with a controller.

[mcw0]

As you can see in my file, I animated "group1".  So you'd need to connect group1.tx to the extension of your boom.  I would group "group1" and parent the new group to the boom arm.  Not the moving boom itself.  Then I would orient this group so that the X axis of "group1" is in the direction of the boom arm extension.  Then create a point constraint on group1.translateX.  Yes, you can do this with setDrivenKeys as well.  But a constraint is simpler.  Actually, you might get away with a direct connection from your boom arm control to group1.translateX.  That would be the best solution.  Many choices.

[J450NP13]

Yeah, I cannot comprehend that right now...lol  

I was kind of thinking I could just attach the tray links to the curve and have them slide on it parented to the object the end one is connected to and then just use a deformer to move the cables.

[mcw0]

Be aware that objects on motion paths should not inherit any transforms from parenting.  So make sure you set "inheritsTransform" off.  That being said, the links should be on the motion path.  Just calculate the offset parameter value for a link.  I'm assuming they are just copies of each other so the offset should be the same.

For the cables, you can use a second curve that matches the curve for the links.  Just make it longer to match the shape of the cables.  Create a cluster at the end of the curve so that it extends with the boom arm.  Rebuild the curve with history so that it gets reparameterized when the shape changes.  Then use this curve to apply a curve warp on the cables.

[J450NP13]

@mcw0 I'm working on it.  I have it kind of working but not as expected.  I'll keep you posted.

[J450NP13]

@mcw0 

So, I went another route.  I created the links and rigged them with joints, then added a curve and then used that curve as the IK handle.  It works good.   I will use a "Set Driven Key" to animate it.  Needs a little cleaning up though.

Now I have to do the cables.  I will keep you posted.

[J450NP13]

@mcw0 

Got the cables done the same way except I just skinned the cables to the joints.

[mcw0]

Well done!!!