Hi! I would love some guidance on the caching of HDA output in unity

The documentation for Houdini Engine for Unity outlines some considerations for version control:
https://www.sidefx.com/docs/unity20.5/_source_control.html#SourceControl_Files [www.sidefx.com]

As I understand it, the caching folder is supposedly a noisy folder where Houdini caches its output geometry and such, but when I work in Unity it seems every HDA is storing its output directly into the scene, or serializing the output in some way. The caching folder is always empty, apart from some folders named after some assets. This often lands us some challenges in terms of the github file limit of 100mb when working with work-in-progress-scenes heavily dependent on Houdini assets.

Is the caching folder still in use, or was the caching behavior an outdated approach? Or, just as likely, am I misunderstanding its function?

Any insight is greatly appreciated!

Is there a way to load the documentation for an HDA through the unity interface (running unity engine)?
I wouldn't be surprised if it is possible with the api, but I can't seem to find anything Perhaps with a python script attached to a button or something along those lines?

Any tips would be greatly appreciated!

Hi Ciscorp, this may not answer you question directly I think, but I'll chime in as best I can.

We're using/trying out multiple approaches, but for me it seems to depend on asset use case.

Things that are isolated assets (like furniture, single trees and such) we use simple fbx from Houdini proper. I use the path attribute and the fbx rop sop to control separation of geometry, which seems to work nicely and predictably.

When it is assets that are dependent on a unity scene, needs to fit with the surrounding geometry, or needs to change depending on level design, I sometimes create an actual HDA for unity. This also seems to work reliably, although it involves slightly more setup. For geometry separations in unity it depends on the use case, but usually it is one of the following approaches:

• Sop leve hdas with packed geometries where the number of sub-geometries are unknown or suitable for instancing.
  
• Sop level hdas with specific output nodes, when the number and type of outputs are predicable.
  
• Object level hdas with sops for each component, in cases where the output is predictable and the asset is more complex.
  

In cases where we do texture baking or texture compositing, we try to do it directly in the hda or use regular rops, but for our production so far we aren't doing much with textures, so there are probably better ways. Similarly, we haven't had need for LODs in our production, if that is what you are creating, so I don't have any good pointers there unfortunately.

In any case, I'm also hoping for some more indepth tutorials on the unity workflow from SideFX, and best of luck

Best,
Marcus

Also, which version control software do you use, and are you happy with it?

Hi!
We've been working a little while with implementing Houdini Engine as part of our pipeline with level designers and artists. While the Houdini side of things is usually smooth sailing, we're still somewhat undecided on good workflow and pipeline practices when using engine in Unity, and especially as it relates to version control.

I wanted to ask if you have any best practices, guidelines or advice on how you implement it in your Unity production pipelines? What are your experience with using it in a team?

For example:

• What strategies have you found most effective for managing Houdini Engine assets, and how do you structure folders, naming conventions and such?
  
• How do you handle scene file size bloat or serialization in regards to version control?
  
• How do you handle merging conflicts changes in Houdini assets or Unity scenes?
  
• To what degree do you create and manage prefabs for different types of assets?
  
• Which version control do you prefer in projects that feature Houdini Engine assets heavily?
  
• To what degree do the different artist disciplines in your team use Houdini Engine tools, and what are their experiences with it so far?
  
• What is your strategy and frequency in terms of engine plugin updates?
  
• Any other pain points, pitfalls or similar you'd recommend being careful with?
  

Any tips, experiences and advice would be most appreciated, and especially in terms of version control. I'm beginning to think git may not be the best options for subsequent projects, but that may be what we're stuck with for now

(For context, we're currently working on a project that will often use simple input geometries to create level terrain/environment which can sometimes be quite large assets, several simple asset creation tools, and some typical engine assets like stairs, walls and the like, which we'd like to keep editable as longs as possible in the development cycle. In other words not particularly vfx heavy, but a lot of asset and level generation tools in the current project, but hopefully more vfx in later projects.)

Best,
Marcus

I'd also love an update on the AliceVision toolset. What is the appropriate AliceVision release to use?

I keep getting errors like: ERROR: unrecognised option '--defaultFocalLengthPix' and similar, depending on which version I try.

Sorry about reviving the old thread.

Just chiming in with my interest on any info on RC support.

Glad you got it sorted. Any eta on H20.0.736 reaching production build?

Sorry to revive this thread

I am having the same issue as Smoluck, and I'd love some way to control the output prefab and mesh name, or at the very least a add prefix to it. Especially because it's quite vulnerable to mistakes when renaming asset manually, not to mention the painful workflow it creates.

I'd prefer not edit the unity plugin itself, as I am not entirely clear how the name is being used in the code, but if that is what it takes . From what I can tell, the name of the prefab is taken from the _assetName property, and the mesh .asset name is taken from the _assetOpName property, but if I edit these, the plugin complains about the names not matching the actual asset, not to mention that these are private properties.

What is the best entry point for overriding the output names in the unity plugin? Alternatively, could we get a simple string field on the HEU_HoudiniAssetRoot object, or even just some way to set it with the HDA itself, similar to the "instance_prefix" or the "unity script" attribute?

Any tips or pointers would be much appreciated!

Hi Aganztracy, I'm all new at this myself, but very often I find myself forgetting to enable gizmos, which hides the whole curve interface as well

Btw, is it a curve sop in an hda you have authored, or are you adding a new curve object directly in unity?

Best,
Marcus

Hi! I'm also running into this

I created a super basic setup with three boxes in which the third box is parented to the second box to test, and box 1 and 2 are parented to a null. One of the boxes also has collision geometry group.

I get similar results as receceasd123 when cooking the node in Unity, where:
1. the master null is duplicated according to how many children there are.
2. the parent/child relationship is ignored, and each box/null is a direct child of the main hda game object.
3. the collision geometry group is imported as separate geometry instead of as collision geometry on the box it belongs to.

Are there any checkboxes I should tick, or something like that, or is this by design?

Any tips or pointers are appreciated Thanks

Weirdly, uninstalling and reinstalling a couple different versions seems to have removed the issue. I'm assuming it was something to do with the version I was using. Unfortunately I didn't make note of which version before uninstalling

Hi!
I have an issue that seems to come up rather frequently, in which the viewport displays geometry as if it is all black, or rather as if the v@Cd is set to 0. Naturally that makes it kind of hard to see anything of what I am doing

It might be something I'm doing wrong, but if it is I'm not sure what it could be. Looking at the geometry spreadsheet it seems to have it's properties set correctly.

It does seem to happen quite randomly though, and I have attached a video showing how the geometry looks correct when opening Houdini, but upon switching the display flag on a couple of nodes it suddenly goes black. Previously it has happened randomly quite often as well, without any pattern I can discern, and with seemingly random nodes in the network view. I sometimes can add a node, in which things look as expected, but after tweaking some settings or switching display flags it goes black again.

Any pointers on what to check in terms of possible solutions?

Best,
Marcus