I had a quick go at setting the spline points in blueprint. If you read the 4.3 release blog post it tells you how.
You can use the AddSplineWorldPoint and SetSplineWorldPoints blueprint functions. Set ‘Allow Spline Editing Per Instance’ to off.
AddSplineWorldPoint will add a single point and you can use for loop and create points or even daisy chain up multiple of these with MakeVector nodes to create the posiitons. The other way is to create a variable array and make it a Vector type then feed that array into the SetSplineWorldPoints function node. You can then enter default values into the array.
The other interesting way to create spline is that you could create them in maya, max or blender and write a script to write out a csv of the spline points positions. Then you can read in that csv file in UE4 and use the data to initialize the array and hence the spline points. You could even create multiple splines in one blueprint (I’m thinking about a tree tool here).
There is a problem I found in that it doesn’t display on the screen if you set the points manually so there is no way to verify if it came in or not.
I was about to record a video but its late so i’ll probably do it tomorrow.