Instance map incorrect when objects are converted from duplicates

[wish2023]

Hi, thanks for the awesome blender utils!

I am trying to convert particle emissions to objects and then segment them, but separate objects are considered to be part of the same instance. Here's the minimal code that will generate the issue

import bpy
import bpycv
import cv2
from bpy import context
import numpy as np

# Scene setup
bpy.ops.object.select_all(action='SELECT')
bpy.ops.object.delete()
bpy.ops.mesh.primitive_cube_add(size=1)
bpy.ops.mesh.primitive_plane_add(size=20,)
bpy.ops.object.camera_add(location=(0, 0, 80), rotation=(0, 0, 0))
bpy.context.scene.camera = context.object
bpy.ops.object.light_add(type='SUN')
cube = bpy.data.objects["Cube"]
plane = bpy.data.objects["Plane"]

ps = plane.modifiers.new("part", 'PARTICLE_SYSTEM')
psys = plane.particle_systems[ps.name]
psys.settings.type = "HAIR"
psys.settings.use_advanced_hair = True
psys.settings.count = 2 # Creating two hair emissions of cube
psys.settings.instance_object = cube # Creating two hair emissions of cube
psys.settings.render_type = "OBJECT"
psys.settings.particle_size = 1

plane.select_set(True)
bpy.ops.object.duplicates_make_real() # Make instanced objects attached to this object real

# Render using bpycv
bpy.data.objects["Cube.001"]["inst_id"] = 1001
bpy.data.objects["Cube.002"]["inst_id"] = 1002
result = bpycv.render_data()
cv2.imwrite("demo.jpg", result["image"][..., ::-1])
cv2.imwrite("demo-seg.png", np.uint16(result["inst"]))

The inst_id are correctly shown in the UI (One cube has inst_id = 1001 and second has inst_id = 1002, but all cubes seem to be in the same instance in demo-seg.png (all cubes have inst_id = 1002)

[DIYer22]

objects["Cuda"] objects["Cuda.001"] and objects["Cuda.002"] have same obj.data, that mean they has same obj.data.materials.

Fix by adding those code

bpy.data.objects["Cube.001"].data = bpy.data.objects["Cube"].data.copy()
bpy.data.objects["Cube.002"].data = bpy.data.objects["Cube"].data.copy()
result = bpycv.render_data()