Whilst in Edit Mode I have my curve set as an object input to a HDA (Adjuster Path) This HDA takes the input and processes the Houdini Curve with attributes and resampling.
It will then get then feed as input to the Terrain HDA that contains the terrain for projection. this chain from Houdini Curve > Adjuster Path > Terrain, all cooks fine in edit mode, and I get the projection result I expect
The problem occurs when I enter Play Mode. The Houdini Curve immediately gets removed from its input and it triggers an additional downstream cook without the input curve. Even after exiting Play Mode, the curve remains removed from input.
For proof you don't actually need to have the set up above to see this issue. its already exists in Houdini Engine → New Node
Steps to Reproduce
- HoudiniEngine → New Node → Select Curve & Input.
- Assign the Houdini Curve into the Input.
- Press Play.
- The curve input is removed and the HDA cooks without it.
What I Tried
- Using a mesh as input - The mesh is not removed when entering Play Mode (makes me think only curve inputs fail to serialize.)
- Using Unity Splines as input - Splines strangely don’t get removed in Play Mode which is nice! However.. I have to manually recook the Input HDA whenever I want to update spline changes. (it would be cool if there was a way to trigger a cook automatically when the Unity Spline updates)
Setup
Using the “new school” curve input method (not editable nodes)
Unity 2022.3.62f1
Unity 6000.0.55f1
Unity 6000.0.30f1
Houdini Engine 20.5.684