Import open world roads in UE4

   1972   4   4
User Avatar
61 posts
Joined: Nov. 2017
Hi there,

trying to bend my head around this for a few days now.

Since I'm creating my terrain and roads (using pathfinding and manual approaches) in Houdini, I wonder how to create/import these roads inside UE4.

I've seen a lot the videos on road creation inside UE4 using splines. The basic seems to be to pathinstance and pathdeform small chunks of road. Very memory friendly. But in all cases the splines were created inside UE4. With an open world which might change during the developments every day, this seems to be a very destructive workflow.

Since I already created my road inside of Houdini (as a nurbs curve, primitive curve or as geometry), what do I do with it to finally create it inside of UE4?

Importing the geo seems like a no go, since in an open world this mesh might be really heavy, although it would be easy to create the geo inside Houdini giving me full control over most parameters. Would UE4 slice this mesh in a memory friendly way, so that it can handle it?

I couldn't find anything yet on importing spline components via an assett, to create the streets with a blueprint. I imaginge since UE4 uses instances for these roads which are bend along the spline, that this might be a good approach, but how would it work practically?

Most of the videos covering this subject show the creation of a small racetracks or something similar. A no brainer in terms of performance, since the geo can be easily imported. But in an openworld with 20km of road this seems to be not the right option, or?

If you have any experience on this subject, I'd be glad if you could share it.

User Avatar
699 posts
Joined: Feb. 2016
User Avatar
12 posts
Joined: Dec. 2019
I've been looking into this same thing, and have not yet found a way.

One approach could be to export polylines and try to construct a blueprint that converts them to UE splines. I haven't tried that yet though.
507 posts
Joined: Sept. 2016

In version1, we unfortunately don't support outputting curves, so the only workaround would be along the lines of what eetu suggested.

Version2 will support outputting curves as Spline Components, so that should probably solve your issue.
Curve output is not in the current v2 Alpha, but will likely be available in the next update.
User Avatar
33 posts
Joined: Feb. 2018
Version2 will support outputting curves as Spline Components

This is great news. Will you also support outputting as landscape splines?
  • Quick Links