Hello
If there is only one Curve(Polygon) in HDA, it will not present in UE4 editor and it can't be used by other HDA in ue4 editor as a World Outliner Input data source.

Hi,

That's expected, the plugin does not support outputing curves, so an HDA with only a curve wont generate anything.

Instead of using a world input on your other HDA, you should be either using a curve input, or make sure that the curve is marked as editable.

For the editable curve sop, create a simple HDA that just contains a Curve SOP.
Add the curve SOP to the HDA's editable node list.
One important thing, is that the curve SOP needs a “preset” (at least a few points), or the plugin will ignore it as its not generating anything. (You need at least two points in order to edit the curve properly in the plugin)

When importing that HDA in unreal, you should be able to edit the curve.
You can then use it in another HDA by using an Asset input, that will directly connect the curve HDA in Houdini

It works for me, thanks!
BTW: I found a bug.
I placed a cb2p(copying box to points) HDA and two curves(polygon with two points) HDA as cb2p's Asset input in the editor scene. Then I added about 10 points for each curve. When switching cb2p's Asset input slection btween the two curves frequently, the editor often crash. It seems to happen when the previous switching input is processing then another input item is clicked.

Hi,

I'm glad your issue's now solved.
Regarding the asset input changes crashes, would you be able to send me the unreal logs when they happened?
(they should be in the /Saved/Logs folder)

Or even better, could you submit a bug for that and attach the logs to it?

Hi,
This bug is submitted on GitHub https://github.com/sideeffects/GameDevelopmentToolset/issues/89 [github.com]