Houdini: add model family (initial support)

[MustafaJafar]

Changelog Description

Adding model family to Houdini.
The main purpose to support Maya (load/publish model from maya to/from houdini).

Additional info

Currently, The new creator plugin is almost the same as 'create_pointcache.py'
But renaming the product type to 'model'.
It's considered to support multiple representations in the future.

Additional info 2

This PR uses collect_instances_type.py to abc family to publish families of Model instances.

Testing notes:

1. Create Model Family
2. Publish Local and on farm.

[moonyuet]

it errors out integrate.py after exporting the object.

[MustafaJafar]

it errors out integrate.py after exporting the object.

Yes, the PR needs small addition to work. I added that info to additional info in the PR description.

I can't decide what solution is favored:

• solution one: implement get_publish_families see Houdini: support get_publish_families method #485
• solution two: remove get_publish_families and add/modify collect_pointcache_type.py to add abc to families associated with model instances.

Also, this comment #486 (comment) should be considered because it affects the execution flow of publishing models.

[moonyuet]

it errors out integrate.py after exporting the object.

Yes, the PR needs small addition to work. I added that info to additional info in the PR description.

I can't decide what solution is favored:

• solution one: implement get_publish_families see Houdini: support get_publish_families method #485
• solution two: remove get_publish_families and add/modify collect_pointcache_type.py to add abc to families associated with model instances.

Also, this comment #486 (comment) should be considered because it affects the execution flow of publishing models.

If you talk about the solution two, you can consider the code below for the model creator. You just need to make sure the identifier is neither io.openpype.creators.houdini.pointcache nor io.openpype.creators.houdini.bgeo. And you can add one more condition to add abc as part of instance.data["families"] if identifier is "io.openpype.creators.houdini.model". Of course, the collector needs better naming after this (maybe rename it as collect_instance_types.py instead of collect_pointcache_type.py)

class ExtractModelABC(ExtractAlembic):
    """Extract model as ABC."""
    identifier = "io.openpype.creators.houdini.model"
    label = "Extract Alembic (Model)"
    families = ["model"]

    # Driven by settings
    optional = True

For solution one, I slightly look at how the creator built in the maya host, guess the published families somehow need to be decided during creating the instance. not sure if we can do some tricks on settings(some multiselection one) to let user decide which families type they want to publish?(not sure if it is a good idea.)

[MustafaJafar]

For solution one, I slightly look at how the creator built in the maya host, guess the published families somehow need to be decided during creating the instance. not sure if we can do some tricks on settings(some multiselection one) to let user decide which families type they want to publish?(not sure if it is a good idea.)

suppose we are allowed to publish multiple representations per product.
Let's take this example I think it can help us:
In publisher UI I'm able to select publishing my model as (we can select them all)

• alembic
• fbx
• usd

For development,
we'd need to add families based on my selection.
So, does get_publish_families support such a scenario ? maybe @BigRoy can tell us ?

Personally, I'd prefer to use get_publish_families because the logic would be saved in one place which is easier to maintain.
That logic only specifies which publish families to use based on the creator attributes.

---

I think we should move this discussion to a dedicated place.
As it's not a necessity for this PR to work.

[MustafaJafar]

In this 475d1db I've added @moonyuet's suggestion about using a collector to add abc to families.

I didn't update extractor because it already runs on Model instances as they already have abc in families list.

ayon-core/client/ayon_core/hosts/houdini/plugins/publish/extract_alembic.py

Lines 11 to 16 in d51e7a9

	class ExtractAlembic(publish.Extractor):
	order = pyblish.api.ExtractorOrder
	label = "Extract Alembic"
	hosts = ["houdini"]
	families = ["abc", "camera"]

[moonyuet]

General model family publishing looks good

[antirotor]

Did a model roundtrip between Houdini and Maya without any issue