No need to be embarrassed. Stuff like that happens all the time.

“$OS will be automatically replaced with the node's name” -> Yes you can make that the default value of a node's parameter and that can be a convenience.

When you bake the HDA to a Static Mesh you should see the LOD options in the Static Mesh Viewer in Unreal (when you double-click on the baked out Static Mesh). Change stuff there until you like it. Then try to update your HDA to bake those settings via unreal_uproperty_ attribute. https://www.sidefx.com/docs/unreal/_attributes.html#AttributesGroups [www.sidefx.com]

If you upload your (fixed) file, I will give it a try.

Finally I've understood previous posts, now it is working fine.
One thing I am curious about, there is a detail panel in asset (like in double click on asset in content browser), is there a way to put some global parameters there?
Right now I can set parameters per actor (it could work on the long ran with multi selection or predefining defaults from Houdini) but to have global parameters it would be nice.

I don't understand what you mean by global parameters. Sometimes it is best to give a brief user-story to describe what you need. Like, how do you imagine something would work.

Global parameters - like in a blueprint you have some parameters - you can set some parameters for all instances of this class of blueprint - in case of LOD it would be ScreenSize. I would like to define those for entire class not for specific actors.
Right now Only way i see it is to make some default values in Houdini.
And I noticed that when you double click on houdini asset in content browser it opens additional details panel, but right now only detail I see there is a path to *.hdalc file. And it would be nice to have ability to put some parameters there.

Most Houdini parameter types are supported by Houdini Engine.
In Houdini:
- Make your HDA editable (rightclick -> Allow editing of contents). You will see red unlocked lock symbol next to it.
- Rightclick on HDA -> type properties.
- Dive into the HDA, rightclick on any parameter -> Export Paramater to Type properties . Now you can see a new entry in the Existing Paramaters list under the Parameters Tab in the Edit Operator Type Proeprties window. When you press Accept, the HDA definition will be updated to contain that parameter.
This parameter should be visible and usable in Houdini Engine in Unreal in the Detail Panel of the HDA. You can also make and link parameters in other ways.

Please read the docs/watch tuts on HDA creation:

https://www.sidefx.com/docs/houdini/assets/asset_ui.html [www.sidefx.com]

Yes, I have paremeters done in such way, but they are displayed only in actor properties.
Here is how:
https://flic.kr/p/2eMWMDy [flic.kr]
On the left - asset details - no params.
On the right - actor details - LOD screensizes.
Or am I still missing something?

Why do you care about the asset details? - I am obviously missing what you want to achieve.
- Just to make clear: To use the output of Houdini Engine in Unreal in your game, you will have to bake the assets to standard Unreal assets. I believe the HDA node in your scene (and it's children) will not be included in a release build, though it might just bake the output on compile - not sure.

DASD
Why do you care about the asset details?

I want to have ability to tweak LOD screenSizes or other parameters for all instances of given HDA class without using Houdini, just parameters in Unreal.

DASD
I believe the HDA node in your scene (and it's children) will not be included in a release build

I've made test with non baked HDA assets and it worked, but I don't remember if it was Shipping build, and don't claim that is good way to go - if not, then fine.

Gomo
I want to have ability to tweak LOD screenSizes or other parameters for all instances of given HDA class without using Houdini, just parameters in Unreal.

I think that is not currently possible. If you want a change across all instances of an HDA you have to do that in the HDA definition in Houdini.

However, in recent releases of Unreal you get a Python API, so I guess you might make a tool that will be able to select HDAs in your scene and change their parameters. But to my understanding this will be overkill and rather useless. I would suggest to figure such things out once and then lock them in in the HDA. Even in worst case scenario, the amount of times to tweak such things can probably be counted on one hand…

I am not sure whether it is part of your issue, but you can give every exposed parameter on your HDA a reasonable preset value that will be prefilled when you put down the HDA (in Unreal or anywhere).

You can also do things with additional parameters that are not exposed, so maybe all the instances of the HDA in Unreal would be able to keep their settings, but you have an offset in the Definition that you can tweak if necessary that changes the final value.

I do see potential for global controls, though. It's probably worth an RFE. Though there are much more pressing issues that should be fixed first (like the ability to set arbitrary Unreal attributes - which might help create workarounds for this issue.)

DASD
You can also do things with additional parameters that are not exposed, so maybe all the instances of the HDA in Unreal would be able to keep their settings, but you have an offset in the Definition that you can tweak if necessary that changes the final value.

That is a good idea, thanks!

DASD
I do see potential for global controls, though. It's probably worth an RFE. Though there are much more pressing issues that should be fixed first (like the ability to set arbitrary Unreal attributes - which might help create workarounds for this issue.)

Agreed.