Printing of slopes is missing the Bidge Layer

[neorm]

Describe the bug If parts are printed with a slope in some cases the top surface gets messy. The Slicer is printing Internal solid Infill on the Infill layer, due to the Speed of the Internal solid Infill it's not working well. It should start with a Bridge Layer first, in some cases, the slicer is doing it. I have made a video to illustrate the problem https://youtu.be/SWV-gBCttPM

3mf File for This Bug Problem slope.zip

To Reproduce Slice attached Part.

Expected behavior Bridge Lines should be printed first on the Infill, and on top of that comes the Internal solid Infill.

Screenshots

Printer model see ZIP File

Desktop (please complete the following information):

• OS: Windows 11
• Bambu Studio SoftFever 1.4.5 / Bambu Studio 1.4.2.13

[SoftFever]

ya, it's bug

[igiannakas]

This is now fixed in the latest 1.8 release following the ports from Noisyfox.

[Jo-Con-El]

@neorm: Could you please verify it and close the issue? Thanks!

[igiannakas]

This is not fixed in 1.9 or earlier. Present also in the latest prusa slicer.

[igiannakas]

@SoftFever

Some progress made on this.

In the print object.cpp -> bridge_over_infill function there is some filtering going on to remove areas where internal bridging may be unnecessary as the infill is thought to be supported adequately from the sparse infill below.

Commenting these lines below out always does internal bridging irrespective of size of the internal overhangs.

                // By shrinking the unsupported area, we avoid making bridges from narrow ensuring region along perimeters.
                unsupported_area   = shrink(unsupported_area, 3 * spacing);
                unsupported_area   = diff(unsupported_area, lower_layer_solids);

[igiannakas]

Funnily enough all slic3r derivative slicers do this as I bet the same filtering code is re-used across Prusa, Bambu and SuperSlicer! Orca may be the first one to "fix" this :D

[igiannakas]

I'll add an option to "Don't filter small internal bridges" and push a PR.

[neorm]

Hi, I'm happy to see that someone is working on it. I'm not at home at the moment. But I'll be back at the weekend, if there is anything i should check let me know. Last time I was checking it the bug was still in there. (2-3 Weeks ago)

edit: Ok, I found the build, will test it when I'm home. I'm so hyped about this, thank you for taking care of it!

[igiannakas]

Hi, I'm happy to see that someone is working on it. I'm not at home at the moment. But I'll be back at the weekend, if there is anything i should check let me know. Last time I was checking it the bug was still in there. (2-3 Weeks ago)

edit: Ok, I found the build, will test it when I'm home. I'm so hyped about this, thank you for taking care of it!

It should be fixed in this build.

however depending on the infill selected, the angle of the slope and the infill density you will get bridging but it may leave a 1 layer gap between it and the solid infill. That shouldn’t matter much at this point as worst case it is supported slightly lower. And much better than before. This is probably the best that can be done for this type of model/ situation.

[igiannakas]

If you do any tests please post them in the above PR.

[neorm]

If you do any tests please post them in the above PR.

ok, i will