I have some really strange problem with splines in my project. They disappear from the scene every time I do certain things.
Those things include:
-adding and scaling null objects or splines,
-scrubbing through timeline,
-adding Point node in the XPresso editor.
If I revert to saved, they get back in place. So I keep saving every step I make until another accident..
My setup is an IK point rig for character animation, just simple geometry using spline wraps. To have more control over it, I used Xpresso to parent nulls to spline points. I have tried to move objects around in the object manager in case the vertical hierarchy would do the trick, but it does not. When I started animating a character, it has become virtually impossible to; every thing I do causes the splines' disappearance. The IK handle lines disappear as well. If you solo them out, you do not see anything: no vertices, and no nulls controlling them whatsoever. They just totally disappear. The spline wrapped capsules which refer to those splines disappear as well, and with deformer off, they reappear again. I am especially bewildered by this because I have another half of objects (character arms) created exactly the same way, and there is no such problem with them at all.
Also, sometimes these splines just change interpolation by themselves, for example, when I open the project.
This is so so strange! I have totally no clue what to do and I am really sad as I have been setting up that rig for quite long.
This may or may not help but I find that when a scene starts to get wonky and I know it's abnormal and not a simple user error then I try two things:
Create a fresh scene file and merge the original into it or copy and paste the part of the hierarchy with issues (which will also copy associated materials).
Also, check your layers and viewport filters just in case.