Hello ,

Is there a way to "promote" some parameters of an HDA to UNREAL, so that the user in a game finds a slider or some kind of control that would modify this parameter for "LIVE" interaction, for example; deforming an object along a curve using a bulge SOP, but with the gamer in control of this deformation during the game?

Thanks you for any hints!

Have a good one!

Houdini Engine can not run HDAs at real time. It is all done on the construction side(since it requires Houdini for cooking). That being said, you can use HDAs to build these unique user interactions content with HDAs, and enable them through blueprints. For example, you could animate the effects of a bulge with vertex animated textures, or baking morph targets into the fbx(Although I am not sure that is supported in UE5). And you can create that content with HDAs in the editor. And use blueprints to give the user control over its strength.

Thanx for steering me towards the real solutions.
I will be more constructive in my approach.

In my use case I'm trying to do modify the parameters via an editor utility widget which isn't at run time, but still in editor. Is that something that is doable with C++ or blueprints/python?

It's not available as a HoudiniAssetActor but if you link the HDA using a HoudiniAssetBlueprint component in a standard actor, you get these:

• Has Parameter
  
• Set Float Parameter
  
• Set Toggle Value At
  

Ideally the other types are added like int, string, etc.

Likewise the file path types in the HDA should be exposed to be set via strings too.



Looking at source it does seem like it's in there but it's not blueprint exposed for some reason.

https://github.com/sideeffects/HoudiniEngineForUnreal/blob/b63f4d863446b066f54dffb425d397cbb1c54516/Source/HoudiniEngineEditor/Public/HoudiniPublicAPIAssetWrapper.h#L698 [github.com]