Hello,

I am evaluating Houdini Engine for UE4, however I have trouble understanding what is expected workflow with session sync.
I would like to improve my building generator while seeing results in UE4 with Session Sync but I have a few issues:

1. My paths in houdini are configured using $HIP what works well when I am using standalone Houdini UI but Session Sync seems to operate on hda instead of hip and does not know where is the hip file therefore $HIP is pointing to some home temp location where my meshes do not exists. What is preferred way of configuring paths, while they are still set as relative?

2. Can I use Session Sync for development rather than debugging? It seems to be very useful not only for debugging but also for adjusting. If I do so, how should I save my project in synced session?. Should I save it to .hip file from Houdini UI or is it automatically propagated to the .hda file which was originally imported to the Unreal?

3. I imaging the ideal workflow in a way that I open up the UE/Houdini UI, these are synced and changes which I do are saved to the hip file / source hda file imported in the engine / actual unreal houdini asset. When I continue later I can open the file from last session and continue. That is not possible as it does not seem to be supported continuing on already saved session because Session Sync will always open new untitled.hip project.

4. Is it possible to export hda from unreal engine back to the .hda file format? That could partly solve my issues as I would be able to always work in Session Sync with my progress saved in the unreal project and then export it in hda if I need to have it in 'native' houdini format.

Thank you!

Hey!

Maybe I can answer some of your questions:

1) $HIP is unknown to UE4. So you should expose the Working Directory of the Scheduler in your HDA and set the directory in UE4.
Every hdaprocessor, file export etc. should refer to the $PDG_DIR variable instead of $HIP.
$PDG_DIR is the Working Directory of the Scheduler (which you set later in UE4).

2), 3) and 4) I think the Session Sync files are only stored in a temporary file.
I wouldn't recommend using it for development (altough you can fix bugs in there and copy them over to your hip).

Thank you for the reply!

1) I will look into this. I have not heard about $PDG_DIR before. In my case I would like to use it for paths to the source .abc files.

2) That would explain why it is rough although it would be pity as it seems to be veru useful for the development too.