Spline Component bugs

Following bugs are observed for the spline Component while using them with blueprints.

  1. The spline cannot be edited inside the BP viewport
  2. The Spline wont be visible if points are added via construction script
  3. There is no function to set Tangent at Points
  1. Splines are not meant to be modified in the BP viewport. You are meant to have the spline in the BP, and then modify them by dragging your BP into the level, and then moving the points.
  2. Make sure you add your points before attaching any meshes to it.
  3. This feature has been requested (UE-14752)

In regards to number 3, it seems that this has been added to the source code (here), and should probably be available for ue4.9.

Hi DrEllisD,

This is great because it would be very helpful to change the tangents type in BP.

The other bug / demand I would like to add to those of Commander Shepard it the fact that we cannot add points to a spline in blueprint code.
Indeed it looks like we can, I’ve been able to add a visible 3D number displayed near each new points, but in practice the spline in the editor main viewport looks unchanged and still has 2 points.
It more looks like a bug to me, and I’ve already submitted a question about this but with no clear solution so far (see link text).

It is quite an important limitation not to be able to add points in the Blueprint viewport, but I find it blocking not to be able to add or remove points in blueprint code.

In the same kind of idea it would also be very useful to have a flag on the spline to prevent the user to manually create or delete points when she manipulates it.

Would it be possible to have some help on this?

Thank you very much,


Yes it looks like there are only two points but they’re not, actually that bug is about new points not being visible until you do a trick each time but the points are always added.

The trick is check and uncheck the option “allow editing in level” or something like that in the spline properties, this somehow refreshes the spline view so you can now see the points you’ve added, but this is still a bug

Yep, indeed I discovered that kind of “accidentally”.
This is cool but quite limited because this option “allow editing in level” is not accessible in Blueprint.
If it was, well it would be heaven: regarding what I’m doing at the moment I would be able to turn off the editing at the beginning of the constructor call, add points and custom tangents and then turn it on again so that the user will have a completely set up spline.

In practice I think not only this state should be accessible in BP but you should also have another flag which is “Allow points manipulation but not editing”. In other words this is a third state for the spline where the user would be able to select and move the points of the spline but not to add nor delete them, neither she could edit the tangent type.
This would allow BP developers to build custom tools and to be sure the user won’t mess up them by playing too much with the spline.

As an example of things I am doing with splines is this ruler: http://www.werwackfx.com/index.php/graphictools/ue4-main/ue4-articles/30-wkmeasuretoolsforue4