Odd crash with 2.8

Question

I have a scene that contains some 2500+ individual meshes. They were imported from a STL and separated via Separate(P)/Loose(L) and the center of each mesh is on the origin. I ran the script below to move the origin of each mesh to the center of mass for each individual mesh.

Now, any time I click edit on a single object in that file, my computer locks up entirely, and even after waiting 60+ minutes, it never comes back. No mouse movement, no response to ctrl-alt-del, nothing.

I was able to save the file to a .blend, but even opening that file, and then clicking edit on any object, the computer again hard locks.

######################
import bpy
import os

def recenter(a):
    a.select_set(True)
    bpy.ops.object.origin_set(type='ORIGIN_CENTER_OF_VOLUME',center='MEDIAN')
    a.select_set(False)

objs=bpy.data.objects[0]

for x in objs:
    print(x.name)
    recenter(x)

Can you share that file, preferably stripped done to a bare minimum of objects necessary to cause this problem? https://blend-exchange.giantcowfilms.com/ — Robert Gützkow, Dec 13 '19 at 17:59
Over 2500 meshes are a challenge even for powerful CPUs/GPUs. Does the scene have to have that many objects? — Lukasz-40sth, Dec 13 '19 at 18:23

batFINGER · Answer 1 · 2019-12-18T13:27:21.580

Select and run once on selection

Issues with question script include

When selecting and using operators don't iterate over all objects in a blend bpy.data.objects use bpy.context.scene.objects instead. This ensures that objects are linked to the context scene. Operators run on context.

Only choose the desired type of object to operate on, in this case assume that's mesh.

Many operators "do their thing" on all objects in the context.selected_objects list. A quick test in UI will confirm for set origin.

Most importantly please read

Python performance with Blender operators

Script below calls 2 operators for 3.5K objects, yours 3.5K operator calls.

Test script, chooses all mesh objects and transforms their origins to center of volume.

import bpy

# select only all mesh objects
bpy.ops.object.select_by_type(type='MESH')
# run once for all selected
bpy.ops.object.origin_set(
        type='ORIGIN_CENTER_OF_VOLUME',
        center='MEDIAN')

My bad.. while cleaning it up for posting, I didn't remove the array index. My actual code was:
first=bpy.data.objects[0] others=bpy.data.objects[1:] for x in others:

I'll try your method. — Stony Smith, Dec 18 '19 at 13:11
Here's the broken file. https://www.dropbox.com/s/q6x18a39yrgcqvh/Broken.blend?dl=0 Just a few minutes ago, i opened this file and started selecting and hiding (H) various objects. After a couple of dozen, my computer again hard-locked. Only power cycling brought it back. — Stony Smith, Dec 18 '19 at 16:04

Odd crash with 2.8

1 Answers1