Hey,

Have you tried refining the proxy mesh output ? (right click > refine)
By default, the plugin uses Houdini Proxy meshes (that's why there's a Houdini logo on top of Flippy).
They are much faster to create than StaticMeshes, but wont come with LODs or colliders.

The idea is that they will give you faster visual feedback when tweaking the parameters - and can easily be refined when you're satisfied with the results.
Proxies can be disabled either in the plugin settings, or in your HDA's detail panel.

Hi,

Please see https://www.sidefx.com/docs/houdini/unreal/attributes.html#generic

Generic attributes can be applied to the HDA itself, if the attribute is set as a detail attribute.

To get the list of attributes that can apply to a given class, type the following CMD in Unreal:

Houdini.DumpGenericAttribute XXX

XXX being the name of the class, in your case, you'll type

Houdini.DumpGenericAttribute UHoudiniAssetComponent

Which will list all properties that can be modified on a HoudiniAssetComponent, you'll be interested in:
unreal_uproperty_bOutputless : bOutputless (Outputless) - UE TYPE: BoolProperty - H TYPE: int.

so to automatically change the "Do Not Generate Outputs" toggle, you want to create the detail attribute "unreal_uproperty_bOutputless" and set its value to 1.

Well, HiddenInGame will be a special case - as it's one of the properties that the plugin controls by default,
if the mesh is visible/invisible/tempalted etc.. in Houdini will control that property - it's also one that we change when switching between proxy / refined meshes etc..

You're basically applying an extra layer by manually overriding this property on top of it - and this could either apply to the whole actor - or individual components...

Your example is also not the best - if you have multiple clearly distinct outputs - why pack and merge everything into a single output instead of using multiple outputs? The plugin does its best to sort that out - but Houdini Engine still see all of this as a single output.

As mentioned above - some attribute working before/after pack is expected
as some properties exist on the static mesh - other on the component/actor - if you want to modify mesh properties place the attribute before the pack - if you want to modify comp/actor properties, place it after.

The spline being separate when baking as one actor is likely to be a bug.

Hi,

You're setting mesh attributes on Points - I'd recommend setting them on primitives instead.

As a rule of thumb
- Set attributes for a mesh you're generating on the primitives
- If instancing, (unreal_instance for example) you can set the attributes on points.
- If using pack primitives - where the attributes is placed matters as well:
Before the pack, and it applies to the generated static mesh,
After the pack, it applies to the generated Instancer component (ISMC, HISMC or SMC)
- If you want to apply attributes to the Houdini Asset Component itself - (change default values of the HDA) - always use detail attributes.

For generic properties, rather than guessing names, just type "Houdini.DumpGenericAttribute CLASSNAME" in the output logs / commands to get a list of all the property that the plugin can see on a given class - with the matching attribute name/type to use in H.

ie:
Houdini.DumpGenericAttribute HoudiniAssetComponent

or

Houdini.DumpGenericAttribute StaticMeshComponent

In your case - switching the wrangle to run on primitive did fix the bake_actor/folder for me.

Hi,

@Morphtek: We just tried on our end and the binaries that ship with the daily build worked fine on multiple windows machine for us.

How did you copy the Houdini Engine plugin ? did you use the old installer or the launcher ?
Was the plugin installed in the engine's plugins folder or the project's plugins folder ?

Hi,

Windows binaries for UE5.5 have been added to today's daily builds!
Mac binaries should follow soon.

Hi,

The current plugin source code is already compatible with 5.5, but you'd need to build the plugin from source.

As for 5.5 binaries, we'll hopefully have them soon.
Epic has decided to bump the compiler version on Windows for 5.5, so it's taking a little longer than usual
since we can't simply update the compiler on our build machines for a version of Houdini that's already in production.

We'll have a look at Mac binaries once we've sorted the issue on Windows.

Hi,

That's unfortunately expected, as HAPI currently doesn't know how to translate COPernicus data.
Support for COPernicus nodes for HAPI/Unreal will be added in future versions of Houdini.

Hi,

Generic property attributes are more aimed towards random properties on objects that are not "manually" supported by the plugin.
For materials, you can just use the "unreal_material" attribute.

Prefixing with the material slot in square brackets is what we use when creating meshes - as one face can only have one material assigned, unreal_material has only one value that can be used to specify the material slot
ie s@unreal_material = "/Path/To/First/Mat/In/First/Slot"
s@unreal_material = "/Path/To/Second/Mat/In/Second/Slot"

With instances - you only have one "point" - so we need to use multiple attributes per material slot as we cannot give the unreal_material attribute multiple values.
In that case, you can just add the index of the material slot you want to change to the attribute name:

For example: SM_Pavement has two material slots
s@unreal_material0 = "/Path/To/First/Mat/In/First/Slot" (or s@unreal_material= XXXX)
s@unreal_material1 = "/Path/To/Second/Mat/In/Second/Slot"
etc..

Hi,

Here's a slightly more detailled step by step

1. Download UE's source code
2. Build Unreal Engine - without the HE plugin, make sure the engine works, and create a new project (c++)
3. Download and install Houdini (a production build recommended) - in your case 20.5.410
4. Download the plugin's source code for the version of H you installed on the git repo's release page
https://github.com/sideeffects/HoudiniEngineForUnreal/releases [github.com]
5. Extract the plugin's source to your project's plugin folder, ideally ending p with something like:
/MyAwesomeProject/Plugins/Runtime/HoudiniEngine
6. The final step is to build the plugin - since we don't provide linux binaries
Update your project's file so it detects the plugin (GenerateProjectFiles)
Build your project - this should build the Houdini Engine plugin with it.


And yes, you need to run source houdini_setup in Houdini before launching unreal, as it sets up the need variable to identify where the Houdini Libraries are.

Hopefully this helps!

Hi,

That is expected as we've deprecated this workflow in Houdini 20.5:
https://www.sidefx.com/docs/houdini20.5/unreal/instancing.html#overriding-deprecated [www.sidefx.com]

Now, you can still use it in 20.5, but need to re-enable it in the plugin settings.
This, however, won't be possible in future versions of Houdini.

What this feature did, was give you the ability to change the instances on the output of the HDA - but if you had multiple variations (ie, replace the blue cone with 3 different tree meshes) then the plugin would randomly assign the variations, with you having no control on the assignment.

Replacement workflow for this would be:
- use geometry inputa, with "export as reference" enabled (since you don't want the full mesh data - just the path to the mesh)
You can then assign the input's points to your instances and get a similar result.
Replacing one of the input mesh will swap the instances as expected.
- You could use string params, as drag and dropping a uasset will extract its path - and then assign that parameter value to the instance point.
You can even set the string param to display as an asset picker by using the "unreal_ref" tag on the param.
see: https://www.sidefx.com/docs/houdini20.5/unreal/parameters.html#strings [www.sidefx.com]

Hi,

Thanks for bringing this up, the issue was caused by a regression in the plugin's code.
This will be fixed in tomorrow's daily build of the plugin.

Hi,

Unfortunately, currently the plugin's public API doesnt support presets - but this would make a great RFE.

Hi,

Tried on my end and I only get wonky geometry when using custom curves - both in H and Unity.
Likely the issue lies in the HDA - as I get the exact same result between Unity and H.

Have you tried using Session Sync to debug your asset?

In Unity: Houdini Engine > Session Sync.
Then in the session sync panel - disconnect (if you already had a session) then start Houdini.

You can then rebuild/recook your HDA - and it will show up in Houdini.

This likely will help you debug your HDA.

Hi,

It seems like there is some confusion here:
The fix for the shaders was in 20.5.340 - so any version after it has the shaders - previous won't.
So by installing 332 - you got a version before the fix - back to the original problem of missing shaders.

Just tried on my end by installing 20.5.359 today - and got no issues on my end with curves (tried unity2022.3 - but I doubt this issue would be related to Unity versions)

Hi,

The issue was likely caused by some of the plugin's URP/HDRP shaders not being present in the plugin's package that ships with the installer.
The github version of the plugin had those - but they were not in the installer.

I fixed the unitypackage in H20.5.340 - so you should no longer need to modify the shaders.

@eseral: Sorry, the 5.4 sources were added for Linux in H20.732 IIRC ?

That's SideFX Labs - not Houdini Engine.

The unreal plugin will be in:
"C:\Program Files\Side Effects Software\Houdini 20.0.749\engine\unreal\5.4"

I pinged Mai to inform him that SideFX Labs is missing its 5.4 plugin.
Though, since it's mostly a Content plugin - I assume it might be fine to just use the 5.3 version with 5.4

Hi,

As mentioned above, that is expected, we had some issues with unity licenses which forced to us to remove the unity plugin from the last production build. Unity finally found a solution to the issue, so the plugin is back in current H20 daily builds.

For steam, you could either switch to the daily20.0 or previous production build branch, as these both have the plugin.
I'd recommend switching to the previous production build (in properties > beta branch, choose the previous 20.0 production build).

When we release the next production build, you can then return to the default H20 branch - as the next prod build will have the unity plugin.

Hi,

Quick update on this, as of today's build (H20.0.736), the Unity plugin is finally back in the installer.
Sorry it took so long, but unfortunately, the issue wasn't on our end, so there wasn't much we could do to speed this up.