Hey,

I'm creating splines inside houdini and are outputting them to unreal with the unreal_output_curve attribute.

We want to use them to have an object moving along a spline but I'm having trouble with the orientation of the curve and the object ends up rotating in different directions on the spline.

I've been trying to use both the point normals and adding the @rot attribute as a quaternion on the spline points to control the orientation but it doesn't seam to do anything, is unreal calculating it's own tangents when it's creating the curve? I can see rotation values on the splines points in the detail panel in unreal but they don't seam to do anything.

Most posts I've found asking about rotations for input curves, I haven't been able to find anything for output curves.

Is there away to solve this with @N and @rot or is there another approach?

Our coder found that Houdini Engine wasn't using the rotations for the spline output and submitted a fix:

https://github.com/sideeffects/HoudiniEngineForUnreal/pull/279/files [github.com]

I wrote a blog post about this very topic recently here [dev.epicgames.com].

@rot should do the trick. I used this workflow since Houdini Engine v2 and it seems to be pretty consistent.