[2.8] Boolean modifier issue

Coding Python Support
1

Hello,

I try to use Boolean modifier in a loop to apply a cut for a range of objects. Here’s my code:

planes_to_cut = []

for obj in bpy.data.objects:
	if "Cut_Me_" in obj.name:
		planes_to_cut.append(obj)
	
for plane in planes_to_cut:
    plane.select_set(True)
    bpy.context.view_layer.objects.active = plane
    print("Now cutting " + plane.name)
    boolean_mod = plane.modifiers.new(type="BOOLEAN", name="Boolean")
    boolean_mod.object = bpy.data.objects["Cube"]
    boolean_mod.operation = 'DIFFERENCE'
    bpy.ops.object.modifier_apply(apply_as='DATA', modifier=boolean_mod.name)
    bpy.ops.object.select_all(action='DESELECT')

bpy.data.objects["Cube"].select_set(True)
bpy.context.view_layer.objects.active = bpy.data.objects["Cube"]
bpy.ops.object.delete(use_global=True)

Unfortunately, the script doesn’t remove my targer object (Cube) after the the end of the loop. It disappears from Outliner but I keep seeing in in a viewport as a part of modified meshes.

My blend file:
Boolean_Problem.blend (656.2 KB)

2

Hi,
to remove an item you can use bpy.data.remove(obj, do_unlink = True).

3

The suggested line of code returns the following error:

Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
AttributeError: 'BlendData' object has no attribute 'remove'

According to documentation it should be bpy.data.objects.remove(obj, do_unlink = True), but I still get no results.

planes_to_cut = []

for obj in bpy.data.objects:
	if "Cut_Me_" in obj.name:
		planes_to_cut.append(obj)
	
for plane in planes_to_cut:
    plane.select_set(True)
    bpy.context.view_layer.objects.active = plane
    print("Now cutting " + plane.name)
    boolean_mod = plane.modifiers.new(type="BOOLEAN", name="Boolean")
    boolean_mod.object = bpy.data.objects["Cube"]
    boolean_mod.operation = 'DIFFERENCE'
    bpy.ops.object.modifier_apply(apply_as='DATA', modifier=boolean_mod.name)
    bpy.ops.object.select_all(action='DESELECT')

bpy.data.objects["Cube"].select_set(True)
bpy.context.view_layer.objects.active = bpy.data.objects["Cube"]
bpy.data.objects.remove(bpy.data.objects["Cube"], do_unlink = True)

image
image1613×703 181 KB

4

Oops, sorry for the mistake.

In your example, the cube’s name is “Cut_Me_2” and in the script only “Cube” is delete.
I try your code and as long as you have a cube name “Cube”, it works.

By the way, you don’t need to select the object you want to remove with the code bpy.data.objects.remove(…)

5

If you open the initial .blend file, you’ll see that cutter’s name is “Cube”.

image
image1421×605 128 KB

The problem is that “Cube” somehow gets merged with cutted meshes when the script ends, so I can’t remove it. Maybe my code produces virtual copies of this “Cube” for each cutted mesh or something like that…
Couls you possibly post a modified version of my code that works for you?

6

booleans
booleans2603×800 1.12 MB

See what I obtain from your code. It works like you wrote it.
Maybe you should reset your scene because I’m unable to reproduce your problem.

7

Have you tried running my code in my scene (see my .blend file ib the first post)?

8

You have to rotate Cut_Me_2 and Cut_Me_3 to 180° on the z axis to fix the problem. (maybe a bug, I don’t have play that much with booleans).
But probably because your meshes is a mess, some artefacs remains. so I create the same objects to show you.
Here your scene : Boolean_Problem.blend (702.6 KB)

1 Like
9

Rotating is not an option, because I don’t know, which planes should be rotated and which shouldn’t. I reported it as a bug.

Thanks for your help!