This is still not supported right now with Houdini Plugin. Sorry.

Hey there, you will need an input in your HDA for curves. This tree is built around the V1 Houdini Engine plugin workflow where embedded curves in your network would be set as editable. Now in V2, you can just set up an input, and in Unity just plug in as many curves as you want. It's a much more flexible system, easier to set up, and the idea is it gives you more control in Unity.

In the HDA, just set the max inputs to 1(find this by right clicking the HDA and go to type properties, and it's under the Basic tab), then in the network replace the `curve_Tree` node at the top of the network with your new Input node(see image). Save that and now in Unity you can set your HDA to use curves and select them from your world.

No worries. Looks like you need to take the (Return Value) from the `Create Empty Input` node, and feed that into your (Target) for the `Set Inputs Object` & (In Input) on `Set Input Parameter` nodes. Both are coming from some other variable, it's a bit blurry to read. But I think if you swap those around, it should work fine.

Here is an example I have working with world inputs on an Object Merge parameter. This grabs everything in my level with that tag, and adds it to my input.

Done and Done. Sorry about all this, I've noticed a couple small bugs like this crop up in regards to the input/outputs change in 20.0 and some older or less common workflows. But the devs have been getting them fixed up super quick, assuming they aren't super busy with high priority things.

Hi Tom, I was able to repro this issue. The `s@unreal_level_path = "{hda_level}";` will work for packed instances but not generated static meshes. I don't see why that would be the case, and will log a bug for this right away.

I don't remember all of the details on this tutorials setup, but I think it was based on UE4s World Composition, and there was even a labs tool that supported it. But now this type of workflow would be replaced with Unreal 5s World Partition system.

And what you can do it take your tiles and use a Heightfield Project and project it back onto a 32,264 heightield and import that as your landscape. And then follow the Houdini Engine docs World Partition setup to get this nicely partitioned in your level. https://www.sidefx.com/docs/houdini/unreal/worldpartition/worldpartition.html [www.sidefx.com]

https://www.sidefx.com/docs/houdini/unreal/apihda.html [www.sidefx.com]

The API docs should have you covered here. You can use the `Create Empty Input` node and set its class to WorldInput. Set the input objects to your selection. There are several ways to get the assets in your world, if you already have them selected, you can use I `Get Selected Assets` node and feed that output directly into the `Set Inputs Object` node.

Follow all the outputs/inputs for wrappers and Houdini API from that image and that should have you cooking(pun intended).

It seems like this might be an Unreal issue. If you think it is a Houdini Engine bug, please submit a bug report. Attaching any files helps us a lot too with fixing these things. A bug report will prioritize this issue for our devs and get you assistance faster.

If you want to select assets from your content browser, change the hdas input from 'world input' to 'geometry input'. object level HDA would make no difference, you're right.

Also, to touch on the other point, while there is more you can do within blueprints and houdini api, by default the hda inputs will take the actors of the blueprint results.

Latest update I've gotten was 5.4 was postponed for tomorrows production build. And will be available on Fridays daily builds, as tomorrow's release didn't give us enough time for testing.

And for 19.5, the fixes will need to be ported over by the team, and will not include binaries for 5.4, and users will need to build it themselves.

Once 5.4 is out of preview mode, we will do our internal changed to the plugin and launch it as soon as we can. Usually it takes around 1-2 weeks after the Unreal version goes live.

Houdini Engine for Unreal works for all version of UE5. 5.0, 5.1, 5.2 and 5.3.

Houdini Engine is also able to read `.hda` files from Core and FX. As well as `.hdalc` files from Indie licenses, and `.hdanc` from Education licenses. It is not able to read assets from Apprentice version of Houdini however.

See the compare page for more info. https://www.sidefx.com/products/compare/ [www.sidefx.com]

I just want to double check one thing. That your curve is set to 1.0 not 2.0. You can change that in the top part of the details panel of your curve, under "asset Name". If this isn't showing up, you need to change one thing in your Houdini. Under the top bar under Assets, go to Asset Definition Toolbar, and set it to always show. Then the option to switch from 2.0 to 1.0 will be available. This should fix the issue for you.

But in Houdini Engine V2, the conventional method to editing curves, is to use your Input as the node to drive the curve. So your "Subnetwork Input #1" would feed into your attribute wrangle.

Then on the Houdini Side, in your HDA details, a new Houdini Input tab will open up. And you can set this to curves, and it will provide you will a suite of curve options. So adding new curves, editing etc.

Note: If you name your Input to "Curve" in the HDAs properties, Houdini Engine will automatically pick up on that name, and set the default Input Type to Curve. And not Geometry, or World Input, the other two options.

Do you have a picture of your node network?

Using editable curves is deprecated, and the new workflow is to use the Unreal curves Input.

That's not to say editable curve nodes won't work entirely. There might just be a simple fix to get this working correctly, but it's hard to say what it is without seeing the node network.

HDAs can adjust the unreal actor properties by using uproperties attribute. In an attribute wrangle, set to points, apply

`@unreal_uproperty_Mobility = 0;`

This will switch bake mobility to Static. 1 Will do Stationary. 2 will be Moveable.

The Unreal parameters we expose as attributes are usually based on what we feel would be used more often by users. Mesh Vertical Offset can still be adjusted with the use of Uproperties. for example, setting a point attribute `@unreal_uproperty_SegmentMeshOffset = 1000;` will change the Mesh Vertical Offset by 1000.


But to be fair, it does seem weird all properties except 1 are exposed. I will write this as an RFE, it makes sense this is should be an attribute.

Thanks for pointing this out!

Michael Pavlovich has a great "Game Dev" series on this on youtube.
There is also "Indie Pixel" for some more Houdini Engine related content on Youtube. It's a mix of free and paid content.
And I have to include Simon Verstraete as well. His Art Station is a great resource

And you would have full control of naming and output folders with Houdini Engine. The Houdini Engine for Unreal documentation is a great resource for all the little pipeline details. https://www.sidefx.com/docs/houdini/unreal/index.html [www.sidefx.com]

Yup, that is a super common workflow in Unreal and Houdini! Editing or creating variations of assets is very easy to do with Houdini, and Houdini Engine lets you run those tools as HDAs directly in Unreal.

I just asked Labs team, and was told there is intention to be an update to VAT later this week. No confirmed date, but keep your eyes open for the update.

Yeah, you are pretty much spot on. You would need to embed the HDA processors in the HDA(this is not editable in Unreal). And there would have to be some level of deconstruction to ensure your pipeline works inside the PDG network. So if you had a process of terrain>road>terrain>road, this could be done with PDG, but each trip would need to be its own unique process(either through HDA, or edited directly in the TOP network). As PDG flows linear, and can't jump back up in the process.

To answer your one question, you couldn't just plug in a building gen HDA or a road gen HDA and have PDG automatically know what to do. You would build this inside PDG as a building gen hda processor, and road gen HDA processor. And its inputs could be other HDAs, but it would be the output of those HDAs from my understanding.

And you can pass information as attributes in your PDG network! But if you had a road HDA with an attribute @lane_count = 6. This attribute will not be processed because the output will be a bgeo file that is passed to your next node, and the @lane_count won't transfer. But you can create and pass these attributes in your PDG network, to inform the next HDA it's intended parameters, being the bridge between these HDAs.



I guess the high level idea is thinking of it like this. There are kind of two main methods of working with HDAs without PDG.

1.You either build all your HDAs individually, (between 6-12) and drop each one down in your world, (creating 100s of HDA actors). These HDAs have no communication, and each need to be managed by hand. ie, Changing X parameter for certain conditions, for X number of HDA actors. And any updates/changes to the HDA need to be managed by hand on a case by case basic.

2.You make one massive HDA, which has those 6-12 HDAs embedded, and you edit these all directly in sops. Full communication! But processing time is slow. One curve move will requires a massive recompile for every dependency. Move a road over 5 feet, every road needs to be rebuild. Then every street light, car placement etc. On top of that, changes to a level can only really be done by one person.


PDG sort of brings the best of both worlds.
1. You connect all of these in a TOP network, as if it was 1 massive HDA network providing full HDA communication.
2. All user edits/parm changes can be handled by your PDG network, automating tedious management in your level.
3. Performance is better. If you move this 1 road curve, PDG identifies what will need to be changed, and what doesn't. And procedurally recook only specific items, speeding up processing time.
4. And this allows for multiple users to edit inputs. And HDA edits to happen independently.

If an HDA is a procedural 3d artist. PDG is a procedural world builder(in this context). Did I sell you on it yet?! hahaha

Here is a fun little tutorial that walks through a PDG network from front to back.
https://www.sidefx.com/tutorials/foundations-build-a-city-with-pdg/ [www.sidefx.com]