In multi material setup, modifier not taking effect

[lalanikarim]

Version

Prusa Slicer 2.1.0

Operating system type + version

Linux

3D printer brand / version + firmware version (if known)

Custom multi material printer. Klipper.

Behavior

When multiple modifiers are applied to a part (extruder 1) where an extruder change is applied to the first modifier (to 2) and the second modifier changes the extruder back to the original (to 1), the second modifier extruder change (to 1) doesn't take effect. (Rook1.3mf)
If the second modifier changes the extruder to some other extruder (to 3), the modifier takes effect.
(Rook2.3mf)

Is this a new feature request? No

Project File (.3MF) where problem occurs

Upload a PrusaSlicer Project File (.3MF) (Plater -> Export plate as 3MF for Slic3r PE 1.41.2 and older, File -> Save / Save Project for PrusaSlicer, Slic3r PE 1.42.0-alpha and newer)
Images (PNG, GIF, JPEG), PDFs or text files could be drag & dropped to the issue directly, while all other files need to be zipped first (.zip, .gz)

Rook1.zip
Rook2.zip

[lalanikarim]

Rook1 Editor View - Part ext 1, Modifier ext 2, Modifier ext 1

Rook1 Preview

Rook2 Editor View - Part ext 1, Modifier ext 2, Modifier ext 3

Rook2 Preview

[bubnikv]

Isn't it a duplicate of #2657 ? po 30. 9. 2019 v 5:09 odesílatel Karim Lalani <[email protected]> napsal:

…

Rook1 Editor View - Part ext 1, Modifier ext 2, Modifier ext 1 [image: image] <https://user-images.githubusercontent.com/1296705/65847006-5e6c2c80-e305-11e9-9e5f-6151459a7d7e.png> Rook1 Preview [image: image] <https://user-images.githubusercontent.com/1296705/65847026-717efc80-e305-11e9-801c-4a7cc9d0382d.png> Rook2 Editor View - Part ext 1, Modifier ext 2, Modifier ext 3 [image: image] <https://user-images.githubusercontent.com/1296705/65847059-970c0600-e305-11e9-8bd8-7c50adde11fb.png> Rook2 Preview [image: image] <https://user-images.githubusercontent.com/1296705/65847076-aab76c80-e305-11e9-889d-e9b68d461cf4.png> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#3012?email_source=notifications&email_token=ABMPSI2RXVD7BONSV3KLLILQMFUX7A5CNFSM4I3VNE3KYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD74I5IY#issuecomment-536383139>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABMPSI4D7GK3FFNNTAK4DODQMFUX7ANCNFSM4I3VNE3A> .

[lalanikarim]

@bubnikv it might be related but definitely not a duplicate. I described a situation where it works the way it is supposed to (Rook2) and another where it doesn't (Rook1).
If a second modifier in an overlapping region wants to reset the extruder back to original value, slicer ignores it. But if it is changed to any other extruder value, it works just fine.

[bubnikv]

I suppose this is the effect you wanted to achieve.

In PrusaSlicer 2.4.0-alpha1 the modifiers were reworked to be applied in the order they are presented at the side panel.