Document how to use group nodes in custom node trees #80827

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Jacques Lucke · 2020-09-16T10:00:46+02:00

Jacques Lucke commented

2020-09-16 10:00:46 +02:00

Maybe I'm missing something, but I could not find documentation on how to use group nodes in custom node trees. The simplest solution is probably to provide an example in the Python docs on the bpy.types.NodeCustomGroup site. Without documenting how this is supposed to be done, we'll likely get more reports like blender/blender#76591.

@randum provided an initial script that can be used. It needs to be refined a bit more though.

node_group.py

Maybe I'm missing something, but I could not find documentation on how to use group nodes in custom node trees. The simplest solution is probably to provide an example in the Python docs on the `bpy.types.NodeCustomGroup` site. Without documenting how this is supposed to be done, we'll likely get more reports like blender/blender#76591. @randum provided an initial script that can be used. It needs to be refined a bit more though. [node_group.py](https://archive.blender.org/developer/F8888411/node_group.py)

Jacques Lucke commented

2020-09-16 10:00:46 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Jacques Lucke commented

2020-09-16 10:00:46 +02:00

Added subscribers: @randum, @JacquesLucke

Jeroen Bakker commented

2020-09-16 13:39:41 +02:00

Added subscriber: @Jeroen-Bakker

Sergey commented

2020-10-12 11:38:29 +02:00

I have started implementing group nodes in Sverchok and I have got some new information which can be added into documentation.

Any addon which uses custom sockets should implement NodeSocketInterface classes for each custom socket. Socket interface has bl_socket_idname attribute which should keep bl_idname of normal socket. Unlike normal sockets interface sockets should be added into tree.inputs or tree.outputs collections. When a socket is plugged to virtual socket of group node the node searches appropriate socket interface by their bl_socket_idname attribute and adds it into tree.inputs or outputs collection. The interface socket can have and draw its properties in node interface panel. According its properties sockets in group node can change their behaviour.

In documentation I have found some methods (register_properties, init_socket, from_socket) which actual interface sockets does not have. Probably documentation is outdated?

>>> D.node_groups- [x].inputs[0]

bpy.data.node_groups['Sverchok group'].inputs[0]

>>> D.node_groups- [x].inputs- [x].bl_rna

<bpy_struct, Struct("SvStringsSocketInterface")>

>>> D.node_groups- [x].inputs- [x].init_socket

Traceback (most recent call last):

File "<blender_console>", line 1, in

AttributeError: 'SvStringsSocketInterface' object has no attribute 'init_socket'

https://docs.blender.org/api/current/bpy.types.NodeSocketInterface.html#bpy.types.NodeSocketInterface.init_socket

Also there is PR on Github dedicated creating UI for node groups. Probably link also can be useful.
https://github.com/nortikin/sverchok/pull/3624

I have started implementing group nodes in Sverchok and I have got some new information which can be added into documentation. Any addon which uses custom sockets should implement `NodeSocketInterface` classes for each custom socket. Socket interface has `bl_socket_idname` attribute which should keep `bl_idname` of normal socket. Unlike normal sockets interface sockets should be added into `tree.inputs` or `tree.outputs` collections. When a socket is plugged to virtual socket of group node the node searches appropriate socket interface by their `bl_socket_idname` attribute and adds it into `tree.inputs or outputs` collection. The interface socket can have and draw its properties in node interface panel. According its properties sockets in group node can change their behaviour. ![95289546-081cbc80-087c-11eb-9a2b-1eb4b17f7c7e.gif](https://archive.blender.org/developer/F8981931/95289546-081cbc80-087c-11eb-9a2b-1eb4b17f7c7e.gif) In documentation I have found some methods (`register_properties`, `init_socket`, `from_socket`) which actual interface sockets does not have. Probably documentation is outdated? ```Text >>> D.node_groups- [x].inputs[0] bpy.data.node_groups['Sverchok group'].inputs[0] >>> D.node_groups- [x].inputs- [x].bl_rna <bpy_struct, Struct("SvStringsSocketInterface")> >>> D.node_groups- [x].inputs- [x].init_socket Traceback (most recent call last): ``` File "<blender_console>", line 1, in <module> ``` AttributeError: 'SvStringsSocketInterface' object has no attribute 'init_socket' ``` https://docs.blender.org/api/current/bpy.types.NodeSocketInterface.html#bpy.types.NodeSocketInterface.init_socket Also there is PR on Github dedicated creating UI for node groups. Probably link also can be useful. https://github.com/nortikin/sverchok/pull/3624

AquaticNightmare commented

2020-10-17 12:32:36 +02:00

Added subscriber: @AquaticNightmare