What's the easiest way to build a standalone GUI tool for our art team to use? Ideally it would let an artist:
- Load in an input file(s)
- Run a specific HDA
- Tweak parameters on the HDA

Effectively I'd like to turn many of the Labs tools into standalone gui apps that our art team can use without booting up Houdini.

I'm aware of Houdini engine, but it seems to be a command-line tool. And even if we executed it in a simple GUI wrapper, it's not trivial to surface all of the parameters and options for them to use.

Any tips? Are there any projects that make this easier?

Houdini Engine lets you load HDAs and tweak their params when creating an object.

BUT... As of my tests on a relatively simple, 121 poly HDA this afternoon on 18.5.462, I'm going to have to say that it's not a tool that I would ever use for production.

The Good:

• Through the use of group names, Unity can detect LOD and collision geometry. These are automatically enabled on import.

The Bad:

• Parameter defaults don't load. All of them get zeroed out. This is unforgivable.
• UI handles don't show up.
• Even with no textures, bake performance is completely unusable on a 4-core machine, and only barely usable with 10 cores.
• Turn on textures and even a 10 core Xeon machine takes several seconds to show the tiniest little change.
• On Windows you get per-poly normal errors that screw up your lighting. My LODs all had different lighting directions.
• On Mac you get noise stripes in the middle of your textures.
• If you use the Labs Substance Material in Unity, only the diffuse map and normal map are exported. Also unforgivable.

So you'll be better off setting up a button to export .fbx files and channel-sorted textures from your HDA in Houdini instead of trying to use this buggy tool in Unity. In fact, I'm probably going to do all of my layout in Houdini and then export changes to .fbx that Unity will then re-load when it detects a file change.

Houdini plugin is convenient, but requiring houdini engine.
you can compile a standalone app using HDK, but much more complicate without node graph. Pure coding.