David_A

Thank you so much sadhu!!
Downloaded and heading to study the file!

Hello everyone!

I am new to Houdini. First post here also.

Please excuse my english, it is not as good as I would like, so I'll try to explain what is the problem I have with the scene I am doing to practice.

I want to do a pipe with some rings attached. I am using a Sweep SOP to make the main pipe. From there I extract a null to do a seconth Sweep using it as a Backbone. The cross section of this seconth Sweep is a rounded square. So far it works OK. If I edit the curve, all the rings continue attached to it so I can animate it.
However, and this is the problem, I see that when the NURBS I am using as a backbone of the pipe starts to curve the rings start to “rotate”, I mean, the rounded square I am using as a cross section of the rings rotates too, yielding a undesirable effect.

I am not sure if I explained it clearly, so I attach the following images to better illustrate what I mean:

So, the rings marked with the green rectangle are correct (no rotation of its cross section), while the red one is incorrect, the cross section has rotated.


When I edit the curve trying to make the backbone of the pipe as much as a straight line, the rings's cross section returns to normal values.


This is my network.


I attached the project file as well.

I do not know what I am missing or what misconception I'm falling in to make the animatable pipe with rings. Any ideas on how to correct this? Any other approach to model this object that you can share?

Thanks!