[SOLVED] How to get a list of face-instanciated child objects?

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1

Hello, I am writing a mesh exporter and in some cases face instancing is used to instantiate children objects but I cannot find a way to get a list of these instances.
image
(This is what I mean by face instancing.)

image
This is how the hierarchy looks like, I would like to get a list of instances of Plane.001 so that I can export them as proper meshes with all necessary transforms set.

2

You might get some clues from the OBJ exporter, as I get correct results with that with face instancing. It’s scripts/addons/io_scene_obj/export_obj.py.

3

Indeed, I think I found some code that could help me, I am going to try it and see if it works.

4

Something like this, I guess:

image
image1919×469 162 KB

Cube: 7 objects
Suzanne: 1 objects

Edit: might want to filter out the instancer itself

5

Yes, this is the code snippet I had in mind. I did something similar to suit my needs, the logic is mostly identical:

    dependency_graph = bpy.context.evaluated_depsgraph_get()
    object_instances = dependency_graph.object_instances
    
    objects_to_export = []
    
    # Copy and prepare the objects we want to export (meshes only). START
    for object in bpy.context.scene.objects:
        if object.type != 'MESH': continue
        if object.hide_viewport : continue
        
        if object.is_instancer:
            #####################################################################################################
            # NOTE: @ for now we assume that the instanciation is 1 level deep and that all instances are meshes.
            #####################################################################################################
            for instance in object_instances:
                parent = instance.parent
                if parent and parent.original == object:
                    instance_object         = instance.instance_object.original
                    new_object              = instance_object.copy()
                    new_object.data         = instance_object.data.copy()
                    new_object.matrix_world = instance.matrix_world.copy() # @ Is taking a copy necessary as we do not modify the matrix?
                    
                    new_object.modifiers.new(name="triangulate_modifier", type='TRIANGULATE')
                    objects_to_export.append(new_object)
        else:
            new_object      = object.copy()
            new_object.data = object.data.copy()
            
            new_object.modifiers.new(name="triangulate_modifier", type='TRIANGULATE')
            objects_to_export.append(new_object)
    # Copy and prepare the objects we want to export (meshes only). END
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