Controller/Spline flipping object

[topquarkone]

Hi,

I have what I think is a very simple spline. It has 6 points, and all of them are on the XY plane. None are rotated. However, when using a Spline Controller, at around 0.77 tf, my controlled object flips orientation by 180 deg, and soon flips back at about 0.77 to it's correct orientation.

Any ideas to what would cause this?

Thanks.

[topquarkone]

Ah, on inspection I see that there is a "twist" in the spline!



This is very strange, as here are the point coordinates:

point
0      0,0,0
1      0,50,0
2      0,100,0
3      50,200,0
4      50,300,0
5      0,400,0
6      0,450,0
7      0,500,0
8      0,1000,0

The twist occurs between point 6 and 7.

[_Aka_]

Hi
You can set explicitly the orientation of a spline at a specific control point by rotating said control point after having set its Orientation Anchor parameter to true. More information here: https://curvyeditor.com/documentation/splines/curvysplinesegment?redirect=1#orientation_anchor
Did this help?

[topquarkone]

Not really. The problem is the kink. I guess this is a property of splines (Catmull). I wasn't expecting a radical twist like there is. I was expecting things to be smooth.

I'll just have to reposition the control points to get what I want...

Thanks.

[_Aka_]

Hi

Yeah I see what you mean. Indeed it is how Catmull splines are. You can use a TCB spline instead. Those splines have 3 settings, Tension, Continuity and Bias. A TCB having 0 as a value for those three parameters is a Catmull. I tried with a Tension of 0.25, and it seems that the issue does not happen with this value. Try different values, or even Bezier splines, that might give splines behaving as you would expect.

I hope this helped. Let me know if you need further help.
If and when you feel like it, please leave a review for the asset, that helps a lot
Have a nice day