I need to draw a path to be followed by an actor (an airplane) this path should be defined in 3d trough level editor. To properly set airplane in space I need to keep actor upvector aligned along the path ( this should be easily achieved using a spline of course)… the blueprint I designed to ‘follow’ the spline track works fine but I noticed that the spline editing phase has some problem.
Defining a path (without elevation on Z axis) usually works fine… but If I try to define a path to simulate something like a loop maneouvre a number of issues comes up, the first one is in the node adding procedure… the context menu says that clicking “shift + period” should add a new node but this will not work since the procedure simply select the next node. The second major issue is given by the upvector of spline nodes… after moving nodes to achieve the desired shape i found some of them to be ‘rolled’ on the spline axis the consequence is that my actor rotate istantly on X axis when traversing such node.
There’s a way to fix such issues?
P.S. Creating a spline circle trough Spline Generation Panel allows to create a correct circle (i.e. with only a twisted node on the end of the spline that can be easily removed) but it’s always placed on X-Y plane with spline upvector oriented along Z axis. There’s a way to change the default creation plane?
Depends on what it is you are using to follow the splines and how.
The spline has hidden controls to adjust the rotations when making loops or tonneau like structures.
The controls aren’t visible when managing the spline, so its a bit hard to figure it out.
Generally, you can switch between the rotation, movement or scale gizmo to adjust the spline point.
Your actor may simply be running into gimbal locking. There’s no way to know based on your post.
To add points, I would suggest alt and drag off the last point.
However the docs say otherwise.
I use the controls to design the spline that are available trough the editor I don’t know if there are other controls available or hidden somewhere… I also enabled the view of roll and scale elements to have more controls over the spline. I don’t know what you’re meaning with gimbal locking but I’m sure that actor behaviour depends on spline and that the sudden change of upvector direction is given by a twist on the spline itself (it’s clearly depicted by enabiling the roll and and scale elements mentioned above), I’ll post a picture soon.
The real problem is how to prevent the creation of such twist, as long as I can see there’s not a way to avoid it unless you use the spline generation panel as I stated above (and you cut out one of the ends of the spline where one of these twist is present) any other attempt to create a loop manually and to fix twisted nodes reversing their updirection leads to other nodes being twisted and so on.
no need to add meshes enabiling roll and and scale elements it’s enough to preview the spline real state … the problem is what triggers the twist and how to prevent it for several reasons:
the twist will often not apply on the last node but often on pre-existant nodes.
once a twist appears it’s pretty difficult to remove unless it appears on one of the terminal nodes.
even if you’re successful in removing one twist adding another node to the spline will often retrigger the twist generation on another node.