View Full Version : Spline control following a deforming object

10-26-2017, 09:05 PM
Spline control is a great feature and I was excited when I found out that Lightwave 2015 added the ability use a modeler spline for spline control. But then I was disappointed that you can’t use any displacement on those splines. I just finished a project where I animated a device being deployed in a blood vessel. I used spline control for this which worked very well. Luckily the blood vessel was in a static position. But I may want to do something like that and have the blood vessel itself be animated with bones. I was playing around with this today and I did find that I could get displacement to work with spline control, although there is a bit of tedious setup. Basically, you can use nodal motion to attach nulls to a spline. Then you can use the nulls as the spline control item instead of the original spline.

In the node setup you can use the point info node to make a null follow the position of a point on the spline. Each node must have its position set individually to the index of the point it is to follow. Attached is example scene that has this working. In this scene the spline is being animated both by nodal displacement and bones. There is also a subdivided plain following the same displacement.

One gotcha I found is that if you save your spline object with a different name, like by saving the object incrementally, all the point info nodes lose their connection to the spline.

Also another tip that I learned from Rebel Hill: Use follower to control the z distance of spline control items. If you don’t you are probably going to be surprised at some point when Lightwave decides to substitute a real-world z position for the spline control distance.



10-27-2017, 03:46 AM
Whoa! 8~

That looks complicated, but also very useful! Great find! :D

10-27-2017, 07:16 AM
Thank you! There is a setup that will incrementally move nulls to the points of another object on duplication. Can’t remember the exact setup off the top of my head, will try and post later. It does involve Sensei’s free nodes and I saw someone on YT (BryPhi I think) do the same setup but with a controller so you could turn off the effect when done.

10-27-2017, 04:09 PM
I would be very interested in finding out a method to automatically have nulls attach themselves incrementally to points on another object. I tried to figure out a way to do that but I couldn't think of anything that would work.

01-23-2018, 08:38 PM
It looks like LW 2018 solves this problem. In 2018 spline control does follow the displacement of Modeler splines.