Use AYON event system for 3dsMax Callback

[moonyuet]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior:

Why isn't 3dsmax using the OpenPype event system like the other hosts? Let's create an issue to track that and fix that in a separate PR. Each host should try and emit the events in a DCC agnostic way so that global OpenPype tooling could hook into it, like scene saves, etc.

Originally posted by @BigRoy in ynput/OpenPype#5499 (comment)

Expected Behavior:

1. Using AYON event system for the callbacks in 3dsmax.
2. Can take references from the Maya hosts.

Version

3.16.5

What platform you are running AYON on?

Windows

Steps To Reproduce:

n/a

Are there any labels you wish to add?

• I have added the relevant labels to the bug report.

Relevant log output:

No response

Additional context:

No response

[cuID:OP-6769]

[BigRoy]

For more details on Max's event system see these documentation pages:

• General Event Callback Mechanism
• Registering Python Callbacks
• File Open Save Callbacks - File Notifications
• File Reset ("new file"?) Callbacks - System Notification

As such it looks like that on host install we should be able to do this in OpenPype:

pseudocode

from functools import partial
from openpype.lib import (
    register_event_callback,
    emit_event
)

import pymxs
rt = pymxs.runtime


def emit_event_notification_param(event):
    notification = rt.callbacks.notificationParam()
    emit_event(event, {"notificationParam": notification})


def register_callbacks():

    id = rt.Name("openpype_callbacks")

    # init
    rt.callbacks.addScript(
        rt.Name('postSystemStartup'),
        partial(emit_event_notification_param, "init"),
        id=id
    )

    # open
    # todo: we might want filePreOpenProcess and filePostOpenProcess?
    rt.callbacks.addScript(
        rt.Name('filePreOpen'),
        partial(emit_event_notification_param, "before.open"),
        id=id
    )
    rt.callbacks.addScript(
        rt.Name('filePostOpen'),
        partial(emit_event_notification_param, "open"),
        id=id
    )

    # save
    # todo: we might want filePreSaveProcess and filePostSaveProcess?
    rt.callbacks.addScript(
        rt.Name('filePreSave'),
        partial(emit_event_notification_param, "save"),
        id=id
    )
    rt.callbacks.addScript(
        rt.Name('filePostSave'),
        partial(emit_event_notification_param, "after.save"),
        id=id
    )

    # new
    # todo: not entirely sure whether systemPostNew means "new file"
    rt.callbacks.addScript(
        rt.Name('systemPostNew'),
        partial(emit_event_notification_param, "new"),
        id=id
    )

Then that would roughly mimic what Maya does by emitting OpenPype events:

• "init" dcc startup initialization finished
• "save" workfile saved
• "open" workfile opened
• "new" new workfile started

Which is implemented in Maya here and then install also install callbacks to those here.

---

Removing all callbacks should then be as easy as:

rt.callbacks.removeScripts(id=rt.name("openpype_callbacks"))

---

I have never worked in 3DsMax so take this with a grain of salt.