Cutting a color painted object removes all paint

[alexzogh]

Describe the bug

I attempted to cut a painted model that was too big for the plate. As soon as I cut the model, all of the paint disappeared on the colored model.

3mf File for This Bug

To Reproduce Steps to reproduce the behavior:

1. choose any painted object in the 3mf
2. Click on the cut icon
3. click on 'perform cut'
4. See error - the object will now be cut, but naked with no paint

Expected behavior

I expected the object to be cut, but all of the paint to be intact

Screenshots

Photo of a selected colored object about to be cut

Photo of the same selected colored object after clicking "perform cut" - all painting has been removed

Desktop (please complete the following information):

• OS: Windows 10 version 22H2
• Bambu Studio version 01.03.01.01

[lanewei120]

it is the current behavior by design, not a bug marked as a feature

[alexzogh]

How in the world is undoing and fundamentally changing everything about an object when you just want it cut a 'feature'? Who in the world would ask for such a feature? When I resize the object I don't lose the painting. When I Split, or modify (add, subtract, etc..) it doesn't lose the painting. So are those all bugs then? Very inconsistent behavior when some features behave one way, and others don't.

[alexzogh]

The original PrusaSlicer keeps the coloring after all model manipulations including a cut

[YifanWuBambu]

@alexzogh @randyre This multi-color model is not generated by the multimaterial painting tool. It's color is assigned by specify the extruder of each part of object in the object list or context menu. Bambu Studio also support this.

Why painted color will be missing after cut operation?

There is some technology limitation that the painted triangles are generated and encoded based on the triangle mesh of an object (here we call it source triangle mesh). So if the source triangle mesh is changed by operations like cut, simplify, the painted triangles not no longer valid. Move/Scale operation does not change the source mesh, so the painted triangles still works.

[ResiduaLiu]

How in the world is undoing and fundamentally changing everything about an object when you just want it cut a 'feature'? Who in the world would ask for such a feature? When I resize the object I don't lose the painting. When I Split, or modify (add, subtract, etc..) it doesn't lose the painting. So are those all bugs then? Very inconsistent behavior when some features behave one way, and others don't.

You are right, but I think you misunderstand the reply. "Marked as feature" means this github issue will be labeled as "feature" rather than "bug". It is a reference for the developers. The Bambu team will solve the problem you proposed.

[rafffel]

Any news about that one ?

[randyre]

@YifanWuBambu Is there a way to have it only affect the triangles that touch the cut and put them back to the base color, and leave the rest of the model colored, That way there's not as much work to do to get painted again.

[bachrach44]

Any update on this? I also find it super annoying to spend all this time coloring an object, only to have all my hard work cancelled when I try to set it up for printing.

[remcoder]

I just ran into this in v1.8.2.56 too. It's a limitation that's easily encountered.

btw, if you lose the colors accidentally this way. At least know you can CTRL-Z to undo the cut.

[partymandkse]

I guess this one have been going one for a while, but i'd like to give my +1 to this annoying issue. Haven't tried Orca slicer yet, but this certainly makes me wannna do it.

[pgifford]

I guess this one have been going one for a while, but i'd like to give my +1 to this annoying issue. Haven't tried Orca slicer yet, but this certainly makes me wannna do it.

OrcaSlicer has the same problem which is not surprising since it is periodically updated to the latest Bambu Studio code.