View Full Version : HELP with curious conveyor belt rig

03-22-2016, 07:57 AM

I'm going crazy trying to animate and rigging an unusual conveyor belt.
Maybe is impossible or i don't know how.

See the Screenshot for the explain.

I try with Spline control with one morph to rotate 90║ at points (A-B-C-D) and instances to plenty of the path.....
But the result is totally uncontrolled and chaotic.

How??? i can't control and do this, I'm lost :confused:

Any Lightwaver help will be welcomed:agree:


03-22-2016, 11:48 AM
Your image looks like spline control should be fine... I suspect theres probably something about how it works you're not familiar with and is thus causing you problems.


04-18-2016, 12:36 AM

I studied your video tutorial about SplineControl. :D:lwicon:

And i was testing and playing with the spline control.

I think i solved it...after many attempts :

-With the Spline control couldn't control the rotation in pitch angles.... And decided to animate one instance with frames.
But,then with the instance multiple doesn't work fine.:cursin:

- I solve it with de Follower motion modifer to ring it.

sure that which it is not the best option :S But it's the best I 've known how to do.

I share in case anyone cares


Thanks again

Sorry for my English

04-18-2016, 12:43 AM
Pitch angles? Do you mean Bank angles?

To my knowledge, the Pitch will be controlled by the path of the Spline (by default: you can disable any channel in the Controllers and Limits tab of the Motion Panel). But the Bank can be adjusted via banking the individual nodes of the spline path. From your sketch, it appears the conveyor belt is horizontal at some points and vertical in others. Does it flip all the way around, or is it more like a steeply banked racetrack?

You're definitely on the right track (hahah!), and SC is the right tool for this task.

04-18-2016, 01:29 AM
could DP Part Move be of help here?

04-18-2016, 11:53 PM
Erikals, I didn't not know until now DP... seems a powerful super tool!

The Work with nodes at now its complicated to understand for me.....I promise learn it.

Any tutorial for DPKIt or information so that it can learn?

04-18-2016, 11:58 PM
I find this information: http://dpont.pagesperso-orange.fr/plugins/nodes/Additionnal_Nodes_2.html

04-19-2016, 12:12 AM
Lytos: Spline Control is orders of magnitude easier to come to grips with than DPKit. Try setting up a real simple situation, like 6 spline nodes, and you'll get a handle on it.

04-19-2016, 12:14 AM
for DPont tutorials, check out Bryan's channel >

also see RH Nodal Tutorials

Lytos: Spline Control is orders of magnitude easier to come to grips with than DPKit.

might be, but i think he referred to DP Part move...

04-19-2016, 01:49 AM
Lytos, here's a conveyor belt done with Spline Control:

Here's the scene file:

The only tricky part here is when you use CURVE TO SPLINE to generate the spline, you need to go back in adjust the HEADINGS on each Joint (which are used to create the spline but could be anything) so that the Heading arrow points along the spline. This avoids the mathematically inescapable (apparently) flips and glitches some users experience. Boring, but easy. The flips show up as constrictions in the spline ribbon.

The other tedious part here was turning off PARENT IN PLACE and parenting 41 cloned belt links together-- I'd like to see an automagic solution for that. Erikals? I mean, 41 is doable, but what if it was 1,075?

Come to think of it, you could probably use Instances. d'oh! :foreheads

One last thing: turn on CLOSED SPLINE to get it to loop. Confusingly, do NOT make a Modeler Closed Spline for this, let Layout close it for you.

04-19-2016, 02:04 AM
Yup, instancing, d'oh. But I do not know why it's offset to the inside like this....
(figured that out)

NOW what I don't know is which parameter gets animated to move the Instances around the spline....

ANS= "Offset", not the tab, the Offset under "Distribute". DONE!

04-19-2016, 02:20 AM
Also, have a look at the content supplied with LightWave. Jen Hachigian did some excellent SplineControl tutorial scenes that are very informative.


04-19-2016, 11:07 AM

04-20-2016, 12:48 AM
Your notes are very interesting and instructional I pledge to practice with them.
I think this can help many Lightwaver┤s Forum

Thanks to share your conveyor belt Jeric_synergy:
But in my belt there were two points in the belt on which the instances had to turn on the pitch angle not the bank.
So just that I had to control this parameter with keyframes and a null to help follow him.

I think like you, instances will be the next solution.

Really the content tutorial scenes that are very informative.

I will try it I have many things to learn yet :nowhere:

Thans :bosdown: Everyone

04-20-2016, 01:41 AM
Hi Lytos:
Perhaps some terminology will clarify the discussion: to me, in Spline Control situations Heading is tangent to the spline in the direction of travel, and Pitch is an sideways and perpendicular vector from Heading (ie "out to the side"), while Bank is rotation around the Heading.

From your description ("there were two points in the belt on which the instances had to turn on the pitch angle not the bank") combined with my definition it sounds like at 2 points your conveyor "trays" (I'm making a bunch of assumptions now) PITCH forward (along their direction of travel), possibly to dump their contents? That IS an interesting problem.

I just experimented with the scene I uploaded yesterday, and A) turning off SPLINE CONTROL on the items' PITCH channels, and then B) keyframing a Pitch value in (45░) left them jumbled in all sorts of rotations! "Interesting!" It may have had something to do with them already being under SC control.... no, wait... that doesn't make any sense. --I don't know what's going on there. (EDIT) Yes I do: all the trays are parented to each other, so the rotations were additive.

To make this automatic, you may have to have some sort of nodal proximity sensor: when the elements of the belt are NEAR some item, they pitch forward. The thing to remember here is you can turn OFF Spline Control on a channel-by-channel basis.

An interesting problem. Attached are some rubbishy tests.

04-20-2016, 05:49 AM
Download this tutorial by Jennifer H.

go to the page shown in this image - you only need standard LW.
- also check Modify>Coord System to get everything rotating correctly.


04-20-2016, 05:58 AM
you'll need the content file.

04-20-2016, 10:43 AM
thanks, scene files are also part of the LightWave 11.6 content i believe

04-20-2016, 02:37 PM
Rotate the nulls you use for your spline. Rotating their bank will affect the orientation of the spline and also the items following it.
Other option is using pole vector for the items. Pole vector always points toward the pole item, there is no flip but you have to animate the pole vector as well.

04-20-2016, 04:53 PM
I think the issue is the need to pitch while moving along the spline. Some more advanced rig may be required than SC.

I look forward to solutions.