Relative directions Bridging/ Top Lines

[Salo92 0]

Hello!

I would love to have control over the direction bridges are generated in across sparse infill (under the experimental bridging settings).
Or an option to set the Top line directions relative to the center of the model (maybe with a checkbox or as [r45, r135]).

Why?
I have a circular model consisting of hundreds of blocks that I'm printing without infill. This makes the top of every block effectively an unsupported overhang, and using normal settings results in ugly scars where the first top layer starts. A solution is under the experimental settings where you can generate bridges across sparse infill. However sometimes the bridging algorithm decides to bridge in the optimal direction (parallel to the outline of the circle) and sometimes the bridge direction is 90 degrees in the wrong direction (see pic).

[gr5 2,170]

Or you could increase the infill amount?  Or use "gradual infill" feature where you increase the infill just a few layers below the "top skin" layers.  "gradual infill" takes some experimenting (all in prepare mode - no need to print the part until you've mastered the settings), but can be quite powerfull.

[Salo92 0]

Thank you for the reply but (gradual) infill isn't what I'm looking for.
After playing with MANY settings and printing over 50 tests I've come to the conclusion that what I need is very specific: I need to control the line direction of the first top layer, relative to the center of the model.
The bridging option over sparse infill already does exactly what I want, the algorithm just seems a little funky when deciding what direction is optimal.
Having a new option to set the Top Line directions being relative to the model instead of absolute would also work.

While my proposed changes sound niche, I think they could be helpful to many people. I'd try writing the code myself but I am a noob and for all talk of Cura being open source I can't find any tutorials on the subject.

The user Burtoogle might have been able to help me but he's gone dark since September...

 

 

Edited June 23, 2021 by Salo92

[gr5 2,170]

Yes you should talk to burtoogle.  He is inactive on this forum but he is responsive on his github account.   I'd repost what you say above onto a github issue (you have to have a github account but they are free).  He created the many of the "experimental" bridging features.  Maybe post something more specific that shows the bug in bridging - post at least a much simpler STL file that shows the problem -- with normal bridging the area to be covered only has walls part way around that you bridge between.  But with "skin over sparse infill bridging", there are walls all the way around so the algorithm was possibly never written to handle which walls to pick - not sure.

 

https://github.com/smartavionics/Cura

[Salo92 0]

Thank you! I will be sure to contact him.