Hello,
I’ve made a very simple HDA to test instancing in Unity (using the “Copy to Points”-Node with “Pack and Instance” ticked to place instances on a curve) , but for some reasons I had trouble to get the result in Unity. After a while I found the “he_curve_instancer”-example in the Houdini Engine-Folder which seems to do roughly the same, so I tested this, and I got the same unexpected results.

Both tools behave like this:

• If „Pack Geometry Before Merging“ (see Screenshot) is ticked, then I get one single instance of the object (should be 5 in the example shown in the screenshot), and it’s placed in the origin, not on the points of the curve
  
• If „Pack Geometry Before Merging“ is unticked, then I don’t get an instance at all
  

Am I’m using it wrong or expecting something it shouldn’t do?

Hello,
in the meantime, I had some time to evaluate it a bit further, it seems to have something to do with the curve input.
I tested it in Unreal (in which it works) and tested it with the InstanceNode instead of the Copy to Points which shows the same result.
Finally (a little late) I then found that part of the documentation that says curve inputs are not supported in Unity, which is kind of a bummer…
www.sidefx.com/docs/unity/_inputs.html [www.sidefx.com]

What I don’t understand is: There is an option to create Curve Assets in Unity (HoudiniEngine>New Curve Asset), so I assume there has to be a way to use it.

Following for example this tutorial (which is a bit older), I assume it should work
www.sidefx.com/tutorials/getting-cozy-with-houdini-engine-lesson-7-procedural-instancing/ [www.sidefx.com]
(You can see how it is used at around 21:40)

What is essentially done there is to create an “OperatorPath” Parameter and connect it to an “ObjectMerge” Node.
When I try to rebuild this, I see an input in Unity in which I can plug in a curve input, but nothing happens.
So my questions would be:

• Should this still work in Houdini 17 the way it is described in the tutorial?
  
• If not, how can I use the Houdini Curve Assets at all, which purpose do they have?
  

(P.S.: The title of this post is a bit misleading now since the topic changed a bit after further evaluating it..)

If you are using a curve asset as input, you need to change the Input Type from UNITY_MESH to HDA.

seelan
If you are using a curve asset as input, you need to change the Input Type from UNITY_MESH to HDA.

Hmm, that's a surprisingly simple answer to a problem that kept me a bit too long busy…
I haven't found that anywhere in the documentation… Though of course I thought I tried it once at the beginning.
Anyway, thank you seelan!